Physical Metallurgy
Design alloys for aircraft engine.
◈ Introduction
When we design alloys for aircraft, we have to consider many kinds of
conditions. They depend on the part of aircraft. Our team choose engine
alloys for our topic and especially We choose turbine alloys. A turbine is a
machine or engine which uses a stream of air, gas, water, or steam to turn a
wheel and produce power. Those three facts need to be regarded for turbine
alloys. Firstly, the property of turbine alloy must have high strength and hightemperature strength, because it spins very rapidly. Secondly, the cost of
material need to be regarded. Thirdly, the weight of material need to be
regarded, because heavy aircraft needs lots of fuel. We are going to consider
those three factors.
◈ Definition.
An aircraft engine is a propulsion system for an aircraft.
Aircraft engines are almost always a type of lightweight
internal combustion engine.
◈ Requirement for aircraft engine
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․
․
․
․
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reliable
lightweight
powerful
small and easily streamlined
repairable
fuel efficient
◈ Problems of materials applied aircraft engine
1) Low room temperature ductility.
2) Creep resistance and fracture toughness become lower as room
temperature ductility increases due to changing of microstructure.
3) Above 800℃, there is the problem of oxidation resistance.
4) Shortage of datum.
5) High cost to manufacture.
◈ FYI : Changing of materials applied aircraft.
1)
2)
3)
4)
Wood.
Aluminum alloy.
Titanium alloy.
Compo-site material.
◈ Design alloys for aircraft engine.
1)
2)
3)
4)
5)
6)
7)
8)
Reliable
Lightweight
Powerful.
Fuel efficient to give the aircraft the range the design requires.
Capable of operating at sufficient altitude for the aircraft.
Safety.
Environmental consideration.
Economical consideration.
◈ Jet Engine
Google Research jet engine image
(http://www.free-online-private-pilot-ground-school.com/turbine-engines.html )
◈ Jet Engine Media player
http://video.naver.com/2008111918405323069
http://blog.naver.com/dreamline20?Redirect=Log&logNo=1300
05560138&vid=0
◈ Considerable Metal Element
1)Iron Alloys
1. Pure iron
2. Carbon steel
C, Mn, P, S, Ni, Cr, Mo
2) Aluminium Alloys
1. 99% Pure Aluminium
2. Al - Cu (4.4%)
3. Al - Cu (4.0%) - Mg(1-1.5%) - Si(0.5%) - Mn(0.5-1%)
4. Duralumin + Mg(0.5%-1.5%)
5. Al - Mn : It has good corrosion resistance.
6. Al - Mn(1.2%) : It has high internal force.
7. Al - Mg(2.5%)
3) Magnesium Alloys
4) Titanium Alloys
◈Turbine - Temperature
Kim Mok-soon, High Temperature Metallic Materials, Inha, 2004
◈ Design new turbine alloys
*NIMONIC alloy 75
(Ni 80.0, Cr 19.5)
*NIMONIC alloy 80A
(Ni 76.0, Cr 19.5, Ti 2.4, Al 1.4)
*NIMONIC alloy 90 / NIMOLOY alloy PK37
(Ni 60.0, Cr 19.5, Co 16.5, Ti 2.5, Al 1.5)
*Jet Engine - Turbine
Ni
60 * 0.93
55.800
Cr
19.5 * 0.93
18.135
Co
16.5 * 0.93
15.345
Ti
2.5 * 0.93
2.325
Al
1.5 * 0.93
1.395
Fe
3 * 0.996
2.988
C
3 * 0.004
0.012
NIMONIC alloy 90
(93%)
FeC (3%)
Mg (4%)
Mg
4.000
*Turbine - Structure
Kim Mok-soon, High Temperature Metallic Materials, Inha, 2004
*Turbine - material
Kim Mok-soon, High Temperature Metallic Materials, Inha, 2004
*Design A New Turbine Alloys For Aircraft
As We mentioned about this project, it's very hard to design new
alloys, so We are going to design a new turbine alloy which is based
on 93% of NIMONIC alloy 90. We choose that 7% of (FeC - Mg)
alloy into the NIMONIC alloy 90. FeC is cheap and it has high
strength. Mg is very light. That is why, they can cover their short
points each others. Following table is a final ratio of new turbine
alloy.
Conclusion
We tried to find out appropriate material of aircraft, and considered
such as high strength and high-temperature strength, cost of material
and the weight of material. We tried to add (FeC - Mg) alloy into the
NIMONIC alloy 90. FeC is heavy but Mg is light. Mg has low hardness
but FeC has high strength. In addition, both materials are cheaper
than Ni (which is main material of NIMONIC alloy 90).
(Ni) U$/ton 8,810 (Mg) U$/ton 3,950
( Base metal, Minor metal http://blog.naver.com/bizdsk?Redirect=Log&logNo=40056770901)
However, our knowledge is not enough to know about everything, and
it's a kind of assumption. The reason is why, it can't be used directly
for real aircraft. It must be verified by correct experiment. However,
We hope that this report is a new attempt of aircraft material
experiment.
Thank You!!
By 1Group