Drilling Advanced Aircraft Structures with PCD Drills
By
Richard Garrick
President
Precorp Inc.
Abstract
With the increased usage of Carbon Fiber Reinforced Plastics (CFRP) in the newest
generation of commercial aircraft, the opportunity for using PCD drills has also
increased. PCD has long been the preferred solution for the drilling of CFRP. However,
given the manufacturing demands of commercial aircraft, a single drilling solution would
be required to drill all possible material stack combinations which include CFRP stacked
with aluminum (Al) and CFRP stacked with titanium (Ti). All of these possible
combinations must be drilled with accuracy, excellent surface finish, minimal coolant
usage and minimal exit burr, over the course of thousands of holes in the least amount of
time possible. Precorp Inc. has developed a PCD drill that successfully drills all possible
stack combinations while meeting the quality criteria. This drill is referred to as the 86
series PCD drill. The 86 series has been applied to an automated drill/fastening system
where holes are not cleaned and de-burred before fastener insertion. In open hole fatigue
testing of holes drilled using the 86 series compared to carbide drills, the holes generated
by use of the 86 series proved to be the highest strength holes produced.
Introduction
Increasing fuel prices combined with a competitive market have forced builders of
commercial aircraft, such as Boeing and Airbus, to change the structures of commercial
aircraft to be lighter and more efficient. This has called for a higher usage of CFRP. The
first commercial aircraft to incorporate CFRP in bulk as the primary structure was the
Boeing 777, first put into service in 1995. This plane incorporated 10 tons of CFRP in its
structure. The next generation of aircraft, the Boeing 787 and the Airbus A380 will
incorporate approximately 35 tons of CFRP in their structure. This fundamental design
change in these aircraft will translate to a 20% more fuel efficient plane compared to
other models of it same size. Structurally, 50% of the weight of the Boeing 787 will be
CFRP. 20% will be aluminum and 15 % will be titanium, the remainder being steel and
various materials.1
The use of these materials combined with the manufacturing demands of the commercial
industry presents new problems. Traditionally, aluminum has been the major component
of the commercial aircraft structure. Easy to drill, the industry has instituted automated
drill and fastener systems that allow a hole to be drilled with inexpensive carbide or high
speed steel drill bits and a fastener to be inserted in 4 seconds. This industry now must
apply these same automated systems to materials that do not allow for the use of a high
speed steel and carbide due to the abrasive nature of the CFRP. In addition, PCD has long
been the preferred method of drilling CFRP,2,3 however tungsten carbide drill bits have
been the preferred tool for drilling titanium. Given the current science, these automated
systems would require a tool change per the material stack drilled.
In the new generation aircraft structures, two materials are stacked, and then a hole is
drilled and a fastener is inserted, thereby fastening the two materials together. In the
majority of the cases, the two materials stacked are CFRP/CFRP. However, in areas of
high load and stress, CFRP may be stacked with aluminum or titanium. In the
manufacturing of the Boeing 787, the drilling and fastening of different sections has been
divided amongst different partners. Below is a table showing the quantities of holes
required per material, per size, for two of the partners.
Partner 1
0.1900
0.2500
0.3125
0.3750
Partner 2
CFRP
5894
2277
154
274
CFRP/Ti
CFRP/Al
CFRP/Ti/Al
673
1822
852
3767
64
CFRP
CFRP/Ti
CFRP/Al
6400
9600
CFRP/Ti/Al
0.1900
0.2500
0.3125
0.3750
4200
1500
300
Table 1. Hole Quantity Requirements for Spirit Aerosystems and Vought Aircraft
Although the majority of the holes are in CFRP/CFRP or CFRP/Al which are easily
drilled using PCD at high speed and feed rates, the limiting factor for the manufacturing
will be the drilling of the titanium which is traditionally drilled at lower speed and feed
rates using tungsten carbide drills.
Stack Material
Tool Material
CFRP/CFRP
PCD
CFRP/Al
PCD
CFRP/Ti
WC
Layer 1
Speed (rpm)
Feed (in/min)
18000
180
18000
180
4500
18
Layer 2
Speed (rpm)
Feed (in/min)
Life(holes drilled)
18000
180
1500
10000
40
1000
700
2
45
0.250" drill
Table 2. Speed and Feed matrix for 0.250” drill in different stack materials
The challenge set forth is to develop a common drill that can be used for all material
stacks, to maximize life and minimize cycle time.
Machining Titanium
The following characteristics of machining titanium are the reasons why PCD has not
been considered a valid solution to drilling titanium.

Titanium is a poor conductor of heat. Heat generated by the cutting action does
not dissipate quickly. Therefore most of the heat generated during the cutting
action is directed to the cutting edge causing the edge of the tool to be subject to
high thermal loads due to the relatively low specific heat, thermal conductivity
and density of titanium.4,6

Titanium has a strong alloying tendency or chemical reactivity with materials in
the cutting tools at tool operating temperatures.

Titanium has a low modulus of elasticity. This requires rigid systems and the use
of sharp, properly shaped cutting tools to prevent the material from moving away.

Titanium fatigue properties are strongly influenced by surface damage. High
surface finishes must be maintained to maximize fatigue properties.

Titanium’s work-hardening characteristics are such that titanium alloys
demonstrate a complete absence of “built up edge”. Because of the lack of
stationary mass of metal (built up edge) ahead of a cutting tool, a high shearing
angle is formed. This causes a thin chip to contact a relatively small area on the
cutting tool face and results in high bearing loads per unit area. The high bearing
force, combined with the friction developed by the chip as it rushes over the
bearing area, results in a great increase in heat on a very localized portion of the
cutting tool.4
Given these characteristics of machining titanium, tungsten carbide is the preferred
method for drilling titanium. Keeping these characteristics in mind, once applied
correctly, the tungsten carbide tool simply wears. If these same principles of machining
titanium were applied correctly to a PCD drill, under the proper drilling conditions, a
PCD drill would be effective in drilling titanium since the ultimate condition is normal
wear.
PCD drill failure in titanium is a mechanical failure. Due to brittle nature of PCD, and the
work hardening properties of titanium, classic failure is an edge failure.
Figure 1. “broken” PCD edge of drill after drilling Titanium
Given the brittle nature of PCD, it is clear that it would be unable to work in the same
operating range as carbide if it were to be a viable solution for drilling titanium. The use
of low cutting speeds would be required. A change of 20 surface per minute to 160
surface feet per minute using carbide tools results in a temperature change from 800 to
1700 F.5 PCD would clearly need to be applied at the lower end of the operating range
with regard to speed without applying excessive thrust to the tool so as to cause the point
to fail.
Figure 2. Showing point failure due to excessive thrust
In order for PCD drills to be used successfully, the following would need to be achieved:
1. A robust drill design with the strongest possible geometry, while maintaining
proper geometry for cutting other materials such as CFRP and aluminum.
2. Speeds and feeds would need to be optimized so as to find the narrow window in
which the balance of forces is such that PCD may survive any mechanical failure.
3. The coolest possible drilling environment must be used.
PCD Veined Drills
PCD veined drills were first patented in 1987 for use in the printed circuit board industry.
Since that time, PCD veined tooling has found application in the medical, ceramic, green
carbide, metal matrix composite, automotive and aircraft industries.
PCD veined drills are manufactured by grinding a slot in a tungsten carbide blank. The
slot is filled with diamond powder then cycled through a PCD sintering process using a
high temperature/high pressure press. The end product is a tungsten carbide blank with a
vein of PCD. This vein configuration may be ground at any geometry needed for the
cutting tool. This blank is then ground into a cutting tool with cutting edges consisting of
PCD.
The advantage of the PCD veined drill is its ability to have positive cutting geometry. It
also allows for smaller sized drills to be manufactured. Non-veined PCD drill technology
incorporates a flat, silver solder brazed wafer. These tools do not have positive geometry
and are limited by the braze joint surface area for smaller sizes.3
PCD Veined Drilling of Titanium
In the development of a PCD drill for titanium, the first step was to apply technology
already proven effective in CFRP and CFRP/AL. Understanding what would be required,
a stronger drill, run at slower speeds was developed. This drill is referred to as the 86
series.
Figure 3. 86 Series Veined Drill
Figure 4. Carbide drill used for drill CFRP/Ti stacks
Once operating parameters were optimized, a 0.2500” PCD veined 86 series was used in
drilling CFRP/Ti and compared to a standard carbide drill commonly used in the industry
today for drilling CFRP/Ti stacks. A Makino A55 horizontal machining center was used
with flood coolant. A peck cycle of 0.040” peck depth was used for the titanium portion
of the stack. Peck cycles are commonly used for CFRP/Ti stacks to prevent damage
caused to the CFRP by the titanium chip exiting the hole.
Material
0.304" thickCFRP/0.242" thick titanium
CFRP
RPM
Feed
6000
60"/MIN
Ti
RPM
Feed
Peck
Depth
700
1.16"/min
.040"
Table 3. Operating parameters of 0.2500” diameter 86 series,
PCD veined drill in CFRP/Ti stack
Standard Drill Hole Size
Hole Size
0.252
0.252
0.2515
0.2515
Size(CFRP)(in)
0.2505
Size(Ti)(in)
0.251
Size (in)
Size
0.251
Size(CFRP)
Size(Ti)
0.2505
0.25
0.25
0.2495
0.2495
0.249
1
21
41
61
81
101
121
141
161
1
181
3
5
7
9
11
13
15
17 19
21
23
25
27
29
31
33
Hole #
Hole Number
Graph 1. Graphs comparing hole size using 86 series veined PCD drill in CFRP/Ti stack
compared to using a standard carbide drill.
The 86 series demonstrates a consistent hole size difference between the CFRP and the
Titanium of approximately 0.0004” over the course of two hundred holes. The carbide
drill showed hole variance over 0.001” over the course of 34 holes.
Standard Drill Exit Burr Size
0.02
0.018
0.018
0.016
0.016
0.014
0.014
0.012
0.01
Exit Burr (IN)
0.008
Size (in)
Size (in)
Exit Burr (IN)
0.02
0.012
0.01
Series1
0.008
0.006
0.006
0.004
0.004
0.002
0.002
0
0
1
21
41
61
81
101
121
141
161
1
181
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
Hole #
Hole Number
Graph 2. Graphs comparing exit burr size using 86 series veined PCD drill in CFRP/Ti
stack compared to using a standard carbide drill.
Exit burr specifications for titanium most drill and fastener systems is for the exit burr to
be less than 0.008”. The PCD drill produced an exit burr less than 0.008” up to 140 holes.
The carbide drill only produced 4 holes with an acceptable exit burr over 34 holes.
Torque (Ncm)
25
20
15
Torque(Ncm)
10
5
0
1
34
67
100
133
166
Hole Number
Graph 3. Torque measured on drill while drilling CFRP/Ti stacks
Thrust(N)
350
300
250
(N)
200
Thrust(N)
150
100
50
0
1
34
67
100
133
166
Hole Number
Graph 4. Thrust measured on 86 series veined drill while drilling CFRP/Ti stack
Torque and thrust followed consistent increases over the course of the 200 hundred holes.
Accepted manufacturing practice is to re-sharpen a PCD drill at 335 N of thrust. This
insures maximum life of the drill while not running a risk of breaking the drill. As shown
in the pictures below, a wear land has formed on the cutting edge of the 86 series PCD
veined drill after the 200 holes in the titanium. This is classic wear that is easily resharpened. The drill may be put back into service after re-sharpening and expected to
achieve the same results as the new drill.
Figure 4. Wear on 86 Series PCD drill after 200 holes
86 Series Applied to Automatic Drill and Fasten Systems
Having proved that the 86 Series can successfully drill CFRP/Ti stacks, the next step was
to apply it to the automated drill fastener system in which a hole must be drilled to finish
tolerances, and a fastener is automatically inserted in one clamping. This would require
that the drill produce a hole within the 0.003” tolerance, with an exit burr that cannot
exceed 0.008”, an interlaminate burr that cannot exceed 0.003”, and maintain a surface
finish less than 64 micro inch. Exit burr size ultimately became the most difficult quality
requirement to achieve therefore, exit burr size became the indicator of tool life and hole
quality.
The process of automatic drill and fasten systems is the part is clamped, a hole is drilled
through the material, a fastener is inserted into that hole, and a collar nut is swaged onto
the fastener. Traditionally, when drilling and fastening CFRP/CFRP, CFRP/Al and
CFRP/Ti stacks, the hole is drilled, then the two panels are pulled apart, cleaned, deburred, then put back together for fastener insertion. The challenge set forth is to produce
a hole that exceeds quality requirements without the need to break down the panel to
clean and de-burr the hole.
One of the difficulties of the application was coolant was not an option due to
requirement of not being able to clean the part. Instead, a minimal quantity lubrication
(MQL) system would be applied. MQL is a cutting lubricant that has been atomized into
an air stream that flows through the tool. MQL serves as a cutting lubricant and lacks the
cooling properties of liquid coolant. Although it does reduce heat caused by friction, this
poses problems as to the life of the tools due to the critical role coolant plays in the
machining of titanium.
In order to qualify the process of the automatic drill fastener system, sample coupons
would need to be drilled using the qualified tooling. Those sample coupons would then be
fatigue tested to determine the strength of the hole. Preliminary testing of various tools
qualified two tools to be used in the fatigue coupon drilling test. They were the Precorp
86 series PCD veined drill and the Precorp 40DH series tungsten carbide drill.
Hole Diameter Delta
Hole Diameter Delta
0.2525
0.2525
0.2515
CFRP H DIA 1
inch max
Ti H DIA 2 inch
max
Upper Limit
0.2505
Diameter (Inches)
Diameter (Inches)
0.2515
Lower Limit
0.2495
0.2485
CFRP H DIA 1
inch max
Ti H DIA 2 inch
max
Upper Limit
0.2505
Lower Limit
0.2495
0.2485
0.2475
0.2475
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97
1
5
9
13
17
21
25
29
33
37
41
Test Hole Number
45
49
53
57
61
65
69
73
77
81
85
89
93
97
Test Hole Number
86 Series PCD Drill
40 DH Tungsten Carbide Drill
Graphs 5 & 6. Hole size produced by the 86 Series PCD drill compared to the 40DH
series tungsten carbide drill.
Burr Data
0.012
0.01
Burr Data
0.012
Deviation (Inches)
0.008
0.01
Deviation (Inches)
0.008
Burr Limits
0.006
Burr Limits
0.006
ILENBURR inches
EXIT BURR inches
0.004
EXIT BURR inches
0.004
0.002
0.002
0
1
0
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
Test Hole Number
86 Series PCD Drill
93
97 101
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97 101
Test Hole Number
40 DH Tungsten Carbide Drill
Graphs 7 & 8. Exit burr size produced by the 86 Series PCD drill compared to the 40DH
series tungsten carbide drill.
Once the 86 series and the 40 DH series were qualified to be used in the fatigue panel
drilling, open hole fatigue panels were drilled. These panels consisted of two holes drilled
into a titanium coupon. Seven coupons of each possible size (0.1875”, 0.2500”, 0.3150”,
0.3750”) were produced using both the 86 series and 40 DH series. These coupons were
then placed in a fatigue cell and cycled until failure.
Due to the proprietary nature of the results, quantitative results are unavailable for this
publication. However, the end users official comment is “the series 86 performed better
than the 40DH, which itself had performed better than any "industry standard" carbide
tool”.
Conclusion
With the increased usage of CFRP in commercial aircraft, PCD will be used more
abundantly throughout the aircraft industry. To maximize the usage of PCD and to reap
the benefits of its usage, PCD may be applied to drilling CFRP/Ti stacks. Because
temperature is the largest factor in machining titanium, best results are achieved when
using liquid coolant. The operating range of PCD veined drills in titanium is narrower
than that of tungsten carbide however once optimized, it can be applied successfully. The
application of PCD veined drills to CFRP/Ti stacks increases tool life and improves hole
quality thereby reducing tool changes and increasing production and tool value.
References
1) Kamiura, Masayoshi, “Toray Carbon Fiber Composite Materials Businesses”,
Toray IR seminar-No.7, June 6, 2005
2) Abrasive Technology, Techview, “AT EverlastTM Veined PCD Drill-A Case
Study”
3) Bunting, John, Precorp Inc., “Drilling Advanced Composites with Diamond
Veined Drills”.
4) www.supraalloys.com/machining_titanium.htm, “Machining Titanium and its
Alloys”.
5) Trucks, Dr. H.E., “Machining Titanium Alloys”, Titanium Industries Inc.
www.titanium.com
6) Deutsche Titan GmbH, “Machining Titanium and Titanium Alloys” Nov. 2000
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semihtml version (cancel wysiwyg) in ocp edit window:
[semihtml]   [box type=curved][hide="Drilling Advanced
Aircraft Structures with PCD Drills, by Rich Garrick&quot;]<br />
[center][b][font size="1.5em"]Drilling Advanced Aircraft Structures with
PCD Drills<br /> <br /> [/font][/b][/center][center]By <br /> <br />
[b]Richard Garrick<br /> President<br /> Precorp Inc.<br /> <br /> <br
/> [/b][/center][font face="verdana,arial,helvetica,sans-serif"
size="2of"][b]Abstract[/b][/font]<br /> <br /> [left]With the increased
usage of Carbon Fiber Reinforced Plastics (CFRP) in the newest
generation of commercial aircraft, the opportunity for using PCD drills
has also increased. PCD has long been the preferred solution for the
drilling of CFRP. However, given the manufacturing demands of commercial
aircraft, a single drilling solution would be required to drill all
possible material stack combinations which include CFRP stacked with
aluminum (Al) and CFRP stacked with titanium (Ti). All of these possible
combinations must be drilled with accuracy, excellent surface finish,
minimal coolant usage and minimal exit burr, over the course of
thousands of holes in the least amount of time possible. Precorp Inc.
has developed a PCD drill that successfully drills all possible stack
combinations while meeting the quality criteria. This drill is referred
to as the 86 series PCD drill. The 86 series has been applied to an
automated drill/fastening system where holes are not cleaned and deburred before fastener insertion. In open hole fatigue testing of holes
drilled using the 86 series compared to carbide drills, the holes
generated by use of the 86 series proved to be the highest strength
holes produced.<br /> <br /> <br /> [/left][font
face="verdana,arial,helvetica,sans-serif"
size="2of"][b]Introduction[/b][/font]<br /> <br /> Increasing fuel
prices combined with a competitive market have forced builders of
commercial aircraft, such as Boeing and Airbus, to change the structures
of commercial aircraft to be lighter and more efficient. This has called
for a higher usage of CFRP. The first commercial aircraft to incorporate
CFRP in bulk as the primary structure was the Boeing 777, first put into
service in 1995. This plane incorporated 10 tons of CFRP in its
structure. The next generation of aircraft, the Boeing 787 and the
Airbus A380 will incorporate approximately 35 tons of CFRP in their
structure. This fundamental design change in these aircraft will
translate to a 20% more fuel efficient plane compared to other models of
it same size. Structurally, 50% of the weight of the Boeing 787 will be
CFRP. 20% will be aluminum and 15 % will be titanium, the remainder
being steel and various materials.[sup]1[/sup]<br /> <br /> The use of
these materials combined with the manufacturing demands of the
commercial industry presents new problems. Traditionally, aluminum has
been the major component of the commercial aircraft structure. Easy to
drill, the industry has instituted automated drill and fastener systems
that allow a hole to be drilled with inexpensive carbide or high speed
steel drill bits and a fastener to be inserted in 4 seconds. This
industry now must apply these same automated systems to materials that
do not allow for the use of a high speed steel and carbide due to the
abrasive nature of the CFRP. In addition, PCD has long been the
preferred method of drilling CFRP,[sup]2,3[/sup] however tungsten
carbide drill bits have been the preferred tool for drilling titanium.
Given the current science, these automated systems would require a tool
change per the material stack drilled. <br /> <br /> In the new
generation aircraft structures, two materials are stacked, and then a
hole is drilled and a fastener is inserted, thereby fastening the two
materials together. In the majority of the cases, the two materials
stacked are CFRP/CFRP. However, in areas of high load and stress, CFRP
may be stacked with aluminum or titanium. In the manufacturing of the
Boeing 787, the drilling and fastening of different sections has been
divided amongst different partners. Below is a table showing the
quantities of holes required per material, per size, for two of the
partners. <br /> <br /> <br /> <table cellspacing="1" cellpadding="1"
border="1" align="center" style="width: 580px;"><tbody><tr><td><table
width="566" rules="none" frame="void" cellspacing="0" cellpadding="0"
border="0" class="MsoNormalTable" style="border-style: none; width:
424%; margin-left: 5.4pt; border-collapse: collapse; float: none; textalign: left; vertical-align: top; background-image: none;"><tbody><tr
style="height: 13.5pt;"><td width="164" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(189, 211, 255) none repeat
scroll 0% 50%; width: 122.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 13.5pt;">[b][font param="Arial" size="10pt"]Partner
1[/font][/b]<br /> <br /> </td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(189, 211,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 13.5pt;">[center][font
param="Arial" size="10pt"]CFRP[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center][font param="Arial"
size="10pt"]CFRP/Ti[/font][/center]</td><td width="178" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(189, 211,
255) none repeat scroll 0% 50%; width: 133.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 13.5pt;">[center][font
param="Arial" size="10pt"]CFRP/Al[/font][/center]</td><td width="81"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 60.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center][font param="Arial"
size="10pt"]CFRP/Ti/Al[/font][/center]</td></tr><tr style="height:
12.75pt;"><td width="164" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 122.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 12.75pt;">[right][font param="Arial"
size="10pt"]0.1900[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-background-
inline-policy: -moz-initial; height: 12.75pt;">[center][font
param="Arial" size="10pt"]5894[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="178"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 133.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="81"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 60.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
12.75pt;"><td width="164" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 122.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 12.75pt;">[right][font param="Arial"
size="10pt"]0.2500[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 12.75pt;">[center][font
param="Arial" size="10pt"]2277[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[font param="Arial"
size="10pt"]673[/font][/center]</td><td width="178" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 133.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 12.75pt;">[center][font
param="Arial" size="10pt"]3767[/font][/center]</td><td width="81"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 60.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]64[/font][/center]</td></tr><tr style="height: 12.75pt;"><td
width="164" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
background: rgb(209, 224, 255) none repeat scroll 0% 50%; width:
122.8pt; -moz-background-clip: -moz-initial; -moz-background-origin: moz-initial; -moz-background-inline-policy: -moz-initial; height:
12.75pt;">[right][font param="Arial"
size="10pt"]0.3125[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 12.75pt;">[center]&nbsp;&nbsp;[font
param="Arial" size="10pt"] 154[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -moz-
background-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]1822[/font][/center]</td><td width="178" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 133.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="81"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 60.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
13.5pt;"><td width="164" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; background: rgb(209, 224, 255) none repeat scroll 0% 50%;
width: 122.8pt; -moz-background-clip: -moz-initial; -moz-backgroundorigin: -moz-initial; -moz-background-inline-policy: -moz-initial;
height: 13.5pt;">[right][font param="Arial"
size="10pt"]0.3750[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 13.5pt;">[center]&nbsp;&nbsp;[font
param="Arial" size="10pt"] 274[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center]&nbsp;&nbsp;[font param="Arial" size="10pt"]
852[/font][/center]</td><td width="178" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 133.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="81" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
background: rgb(209, 224, 255) none repeat scroll 0% 50%; width: 60.8pt;
-moz-background-clip: -moz-initial; -moz-background-origin: -mozinitial; -moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
12.75pt;"><td width="164" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; width: 122.8pt; height: 12.75pt;"><br /> <br
/> </td><td width="77" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; width: 57.8pt; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; width:
49.15pt; height: 12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="178" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 133.8pt; height: 12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="81" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 60.8pt; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
13.5pt;"><td width="164" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; background: rgb(189, 211, 255) none repeat scroll 0% 50%;
width: 122.8pt; -moz-background-clip: -moz-initial; -moz-backgroundorigin: -moz-initial; -moz-background-inline-policy: -moz-initial;
height: 13.5pt;">[b][font param="Arial" size="10pt"]Partner
2[/font][/b]<br /> <br /> </td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(189, 211,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 13.5pt;">[center][font
param="Arial" size="10pt"]CFRP[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center][font param="Arial"
size="10pt"]CFRP/Ti[/font][/center]</td><td width="178" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(189, 211,
255) none repeat scroll 0% 50%; width: 133.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 13.5pt;">[center][font
param="Arial" size="10pt"]CFRP/Al[/font][/center]</td><td width="81"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 60.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center][font param="Arial"
size="10pt"]CFRP/Ti/Al[/font][/center]</td></tr><tr style="height:
12.75pt;"><td width="164" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 122.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 12.75pt;">[right][font param="Arial"
size="10pt"]0.1900[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="178"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 133.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]6400[/font][/center]</td><td width="81" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 60.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
12.75pt;"><td width="164" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 122.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 12.75pt;">[right][font param="Arial"
size="10pt"]0.2500[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-background-
inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]4200[/font][/center]</td><td width="178" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 133.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 12.75pt;">[center][font
param="Arial" size="10pt"]9600[/font][/center]</td><td width="81"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 60.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
12.75pt;"><td width="164" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 122.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 12.75pt;">[right][font param="Arial"
size="10pt"]0.3125[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]1500[/font][/center]</td><td width="178" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 133.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="81"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 60.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
13.5pt;"><td width="164" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; background: rgb(209, 224, 255) none repeat scroll 0% 50%;
width: 122.8pt; -moz-background-clip: -moz-initial; -moz-backgroundorigin: -moz-initial; -moz-background-inline-policy: -moz-initial;
height: 13.5pt;">[right][font param="Arial"
size="10pt"]0.3750[/font][/right]</td><td width="77" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 57.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height:
13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.15pt; -moz-
background-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center]&nbsp;&nbsp;[font param="Arial" size="10pt"]
300[/font][/center]</td><td width="178" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 133.8pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="81" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
background: rgb(209, 224, 255) none repeat scroll 0% 50%; width: 60.8pt;
-moz-background-clip: -moz-initial; -moz-background-origin: -mozinitial; -moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center]&nbsp;&nbsp;[/center]</td></tr></tbody></table></td></t
r></tbody></table>[center][b]Table 1[/b]. Hole Quantity Requirements for
[b]Spirit Aerosystems[/b] and [b]Vought Aircraft[/b][/center] <br />
Although the majority of the holes are in CFRP/CFRP or CFRP/Al which are
easily drilled using PCD at high speed and feed rates, the limiting
factor for the manufacturing will be the drilling of the titanium which
is traditionally drilled at lower speed and feed rates using tungsten
carbide drills.<br /> <br /> <br /> <table cellspacing="1"
cellpadding="1" border="1" align="center" style="width:
580px;"><tbody><tr><td style="width: 100%;"><table width="514"
rules="none" frame="void" cellspacing="0" cellpadding="0" border="0"
class="MsoNormalTable" style="border-style: none; width: 385%; marginleft: 4.9pt; border-collapse: collapse; float: none; text-align: left;
vertical-align: top; background-image: none;"><tbody><tr style="height:
12.75pt;"><td width="85" rowspan="9" style="border-style: none; padding:
0cm 5.4pt; background: rgb(141, 184, 253) none repeat scroll 0% 50%;
width: 63%; -moz-background-clip: -moz-initial; -moz-background-origin:
-moz-initial; -moz-background-inline-policy: -moz-initial; height: 12%;
text-align: left; vertical-align: middle;">[center][font param="Arial"
size="10pt"]0.250&quot; drill[/font][/center]</td><td width="85"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 63.5pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="120"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 90pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height: 12.75pt;">[b][font
param="Arial" size="10pt"]Stack Material[/font][/b]<br /> </td><td
width="91" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
background: rgb(189, 211, 255) none repeat scroll 0% 50%; width:
68.05pt; -moz-background-clip: -moz-initial; -moz-background-origin: moz-initial; -moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][b][font param="Arial"
size="10pt"]CFRP/CFRP[/font][/b][/center]</td><td width="68"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 50.8pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][b][font param="Arial"
size="10pt"]CFRP/Al[/font][/b][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 49.7pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][b][font param="Arial"
size="10pt"]CFRP/Ti[/font][/b][/center]</td></tr><tr style="height:
13.5pt;"><td width="85" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; background: rgb(189, 211, 255) none repeat scroll 0% 50%;
width: 63.5pt; -moz-background-clip: -moz-initial; -moz-backgroundorigin: -moz-initial; -moz-background-inline-policy: -moz-initial;
height: 13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td width="120"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 90pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height: 13.5pt;">[b][font
param="Arial" size="10pt"]Tool Material[/font][/b]<br /> </td><td
width="91" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
background: rgb(189, 211, 255) none repeat scroll 0% 50%; width:
68.05pt; -moz-background-clip: -moz-initial; -moz-background-origin: moz-initial; -moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center][b][font param="Arial"
size="10pt"]PCD[/font][/b][/center]</td><td width="68" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(189, 211,
255) none repeat scroll 0% 50%; width: 50.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 13.5pt;">[center][b][font
param="Arial" size="10pt"]PCD[/font][/b][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(189, 211, 255) none repeat scroll 0% 50%; width: 49.7pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center][b][font param="Arial"
size="10pt"]WC[/font][/b][/center]</td></tr><tr style="height:
13.5pt;"><td width="85" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; width: 63.5pt; height:
13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td width="120"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; width: 90pt;
height: 13.5pt;"><br /> <br /> </td><td width="91" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; width: 68.05pt; height:
13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td width="68"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; width:
50.8pt; height: 13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="66" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 49.7pt; height:
13.5pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
13.5pt;"><td width="85" valign="bottom" nowrap="nowrap" style="borderstyle: none; padding: 0cm 5.4pt; background: rgb(209, 224, 255) none
repeat scroll 0% 50%; width: 63%; -moz-background-clip: -moz-initial; moz-background-origin: -moz-initial; -moz-background-inline-policy: moz-initial; height: 13%; text-align: left; vertical-align:
middle;">[center][font param="Arial" size="10pt"]Layer
1[/font][/center]</td><td width="120" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 90pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 13.5pt;">[font param="Arial" size="10pt"]Speed
(rpm)[/font]<br /> </td><td width="91" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 68.05pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 13.5pt;">[center][font param="Arial"
size="10pt"]18000[/font][/center]</td><td width="68" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 50.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 13.5pt;">[center][font
param="Arial" size="10pt"]18000[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.7pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
13.5pt;">[center][font param="Arial"
size="10pt"]4500[/font][/center]</td></tr><tr style="height:
12.75pt;"><td width="85" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; background: rgb(209, 224, 255) none repeat scroll 0% 50%;
width: 63.5pt; -moz-background-clip: -moz-initial; -moz-backgroundorigin: -moz-initial; -moz-background-inline-policy: -moz-initial;
height: 12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="120"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 90pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height: 12.75pt;">[font
param="Arial" size="10pt"]Feed (in/min)[/font]<br /> </td><td width="91"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 68.05pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]180[/font][/center]</td><td width="68" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 50.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 12.75pt;">[center][font
param="Arial" size="10pt"]180[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.7pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]18[/font][/center]</td></tr><tr style="height: 12.75pt;"><td
width="85" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 63.5pt; height: 12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="120" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 90pt; height: 12.75pt;"><br /> <br /> </td><td width="91"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; width:
68.05pt; height: 12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="68" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 50.8pt; height: 12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="66" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 49.7pt; height:
12.75pt;">[center]&nbsp;&nbsp;[/center]</td></tr><tr style="height:
12.75pt;"><td width="85" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; background: rgb(209, 224, 255) none repeat scroll 0% 50%;
width: 63.5pt; -moz-background-clip: -moz-initial; -moz-backgroundorigin: -moz-initial; -moz-background-inline-policy: -moz-initial;
height: 12.75pt;">[center][font param="Arial" size="10pt"]Layer
2[/font][/center]</td><td width="120" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 90pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -moz-
initial; height: 12.75pt;">[font param="Arial" size="10pt"]Speed
(rpm)[/font]<br /> </td><td width="91" valign="bottom" nowrap="nowrap"
style="padding: 0cm 5.4pt; background: rgb(209, 224, 255) none repeat
scroll 0% 50%; width: 68.05pt; -moz-background-clip: -moz-initial; -mozbackground-origin: -moz-initial; -moz-background-inline-policy: -mozinitial; height: 12.75pt;">[center][font param="Arial"
size="10pt"]18000[/font][/center]</td><td width="68" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 50.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 12.75pt;">[center][font
param="Arial" size="10pt"]10000[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.7pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]700[/font][/center]</td></tr><tr style="height:
12.75pt;"><td width="85" valign="bottom" nowrap="nowrap" style="padding:
0cm 5.4pt; background: rgb(209, 224, 255) none repeat scroll 0% 50%;
width: 63.5pt; -moz-background-clip: -moz-initial; -moz-backgroundorigin: -moz-initial; -moz-background-inline-policy: -moz-initial;
height: 12.75pt;">[center]&nbsp;&nbsp;[/center]</td><td width="120"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 90pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height: 12.75pt;">[font
param="Arial" size="10pt"]Feed (in/min)[/font]<br /> </td><td width="91"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 68.05pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]180[/font][/center]</td><td width="68" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; background: rgb(209, 224,
255) none repeat scroll 0% 50%; width: 50.8pt; -moz-background-clip: moz-initial; -moz-background-origin: -moz-initial; -moz-backgroundinline-policy: -moz-initial; height: 12.75pt;">[center][font
param="Arial" size="10pt"]40[/font][/center]</td><td width="66"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; background:
rgb(209, 224, 255) none repeat scroll 0% 50%; width: 49.7pt; -mozbackground-clip: -moz-initial; -moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial; height:
12.75pt;">[center][font param="Arial"
size="10pt"]2[/font][/center]</td></tr><tr style="height: 13.5pt;"><td
width="85" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 63.5pt; height: 13.5pt;">[center]&nbsp;&nbsp;[/center]</td><td
width="120" valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt;
width: 90pt; height: 13.5pt;"><br /> <br /> [font param="Arial"
size="10pt"]Life (holes drilled)<br /> <br /> [/font]</td><td width="91"
valign="bottom" nowrap="nowrap" style="padding: 0cm 5.4pt; width:
68.05pt; height: 13.5pt;">[center]<br /> <br /> [font param="Arial"
size="10pt"]1500[/font][/center]</td><td width="68" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; width: 50.8pt; height:
13.5pt;">[center]<br /> <br /> [font param="Arial"
size="10pt"]1000[/font][/center]</td><td width="66" valign="bottom"
nowrap="nowrap" style="padding: 0cm 5.4pt; width: 49.7pt; height:
13.5pt;">[center]<br /> <br /> [font param="Arial"
size="10pt"]45[/font][/center]</td></tr></tbody></table></td></tr></tbod
y></table>[center][font param="Times New Roman" size="12pt"][b]Table
2[/b]. Speed and Feed matrix for 0.250&quot; drill in different stack
materials[/font]<br /> <br /> [/center]The challenge set forth is to
develop a common drill that can be used for all material stacks, to
maximize life and minimize cycle time.<br /> <br /> <br /> [b][font
param="Times New Roman" size="12pt"][font
face="verdana,arial,helvetica,sans-serif" size="2of"]Machining
Titanium[/font]<br /> <br /> [/font][/b]The [font
face="verdana,arial,helvetica,sans-serif"]following
[/font]characteristics of machining titanium are the reasons why PCD has
not been considered a valid solution to drilling titanium.<br /> <br />
<ul type="disc" style="margin-top: 0cm;"><li class="MsoNormal">Titanium
is a poor conductor of heat. Heat generated by the cutting action does
not dissipate quickly. Therefore most of the heat generated during the
cutting action is directed to the cutting edge causing the edge of the
tool to be subject to high thermal loads due to the relatively low
specific heat, thermal conductivity and density of
titanium.[sup]4,6[/sup]</li></ul><sup /><ul type="disc" style="margintop: 0cm;"><li class="MsoNormal">Titanium has a strong alloying tendency
or chemical reactivity with materials in the cutting tools at tool
operating temperatures.</li></ul><ul type="disc" style="margin-top:
0cm;"><li class="MsoNormal">Titanium has a low modulus of elasticity.
This requires rigid systems and the use of sharp, properly shaped
cutting tools to prevent the material from moving away.</li></ul><ul
type="disc" style="margin-top: 0cm;"><li class="MsoNormal">Titanium
fatigue properties are strongly influenced by surface damage. High
surface finishes must be maintained to maximize fatigue
properties.</li></ul><ul type="disc" style="margin-top: 0cm;"><li
class="MsoNormal">Titanium’s work-hardening characteristics are such
that titanium alloys demonstrate a complete absence of &quot;built up
edge&quot;. Because of the lack of stationary mass of metal (built up
edge) ahead of a cutting tool, a high shearing angle is formed. This
causes a thin chip to contact a relatively small area on the cutting
tool face and results in high bearing loads per unit area. The high
bearing force, combined with the friction developed by the chip as it
rushes over the bearing area, results in a great increase in heat on a
very localized portion of the cutting tool.[sup]4[/sup]</li></ul>Given
these characteristics of machining titanium, tungsten carbide is the
preferred method for drilling titanium. Keeping these characteristics in
mind, once applied correctly, the tungsten carbide tool simply wears. If
these same principles of machining titanium were applied correctly to a
PCD drill, under the proper drilling conditions, a PCD drill would be
effective in drilling titanium since the ultimate condition is normal
wear.<br /> <br /> PCD drill failure in titanium is a mechanical
failure. Due to brittle nature of PCD, and the work hardening properties
of titanium, classic failure is an edge failure.<br /> <br /> <br /> <br
/> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />
<br /> <br /> [/hide]<br /> <br /> [/box] <br /> <br /> [box
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CFRP/Ti Advanced Composite Stack Material&quot;]<br /> bla bla<br />
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