MMT QUESTION BANK
BY
KOMAL VERMA
UNIT-1
1. Classify the metal removal process and machines in brief.
2. Explain the geometry of single point cutting tool along with their angles and explain the tool
signature also.
3. Define tool nomenclature system with the help of following:
•
ASA
•
ORS
•
NRS
4. Explain the mechanism of chip formation.
5. What are the different types of chip formation? Explain with neat sketch.
6. What is chip breaker? Explain.
7. Compare the orthogonal & oblique cutting.
8. What are the different types of cutting force and also give the power required for metal cutting?
9. Explain the theories of metal cutting in detail.
10. Explain the friction in metal cutting process.
11. What are the thermal aspects of machining?
12. Explain measurement of chip tool interface temperature in machining process.
13. Drive inter relationship between ORS and ASA systems using inclination angle. Rake angle &
cutting edge angle.
14. Describe tool with 9, 11, 7, 7, 7, 10 and 4 signatures in ASA &ORS system.
15. In orthogonal turning of a 50 mm dia. mild steel bar on a lathe the following data were
obtained: Rake angle=15, cutting speed=100m/min, 0.2 mm rev, cutting force= 180 kg, feed
force= 60 kg. Calculate the shear plane angle(φ), coefficient of friction(μ), cutting power, the
chip flow velocity(Vc) and shear force, if the chip thickness= 0.3 mm.
UNIT-2
1.
What are the various types of cutting fluids? Explain in brief.
2.
Explain the effects of cutting parameters on cutting speeds and
feed.
3.
Discus the importance of shear angle from the stand point of
metal cutting performance. What factors influence its value?
4.
Which are the suitable tool future criteria that are generally
practiced in industries? Explain your answer with examples.
5.
A 600 mm long job of diameter 150 mm of steel is to be turn with
a depth of a 1.5 mm & feed rate 0.25 mm/rev. the following data is applicable for the problem:
(i)
Tool cost= rs. 40
(ii)
Tool change time = 1.5 min
(iii)
Labour cost /hr = Rs. 12
(iv)
Machine overhead/hr = Rs. 40
(v)
Tool cutting edge = 8
(vi)
Ideal time = 5 min.
(vii)
VT.22
Find the optimum cutting speed, tool life and the cost of operation for the throwaway type tool using
minimum cost criteria.
6.
Write short note on cutting tool materials.
7.
Differentiate between Emulsion and sulpherised fatty mineral.
8.
Differentiate Plain Tungsten Carbide and Coated Carbide Tools.
9.
What are the effect of the following variables on tool life:
(i)
Cutting Speed, feed and depth of cut
(ii)
Tool material and tool geometry
10.
Write short note on Thermal Aspects of metal machining.
11.
A carbide cutting tool tested for 3 hours while machining MS at 40
m/min. If a similar tool is used a 30% higher speed to machine MS. Calculate the value of cutting
speed if the tool is to machine for 2 hours. Assume n= 0.27 in Taylor’s tool life equation VTn = C.
12.
Describe adhesion, diffusion and electrochemical mechanism of
tool wear.
13.
Show that the cutting speed for minimum cost of production is
given by:
Vmin = C/[(1/n-1)(Ct + Tr /Cn )]n
Where
Tr= Tool changing time
Ct = Cost of tool per cutting edge
Cm = Cost of operating time/min
C = constant in taylor’s tool life equation
N = Index
14.
How will you measure the temperature at the tool point, using tool chip
thermocouple techniques? Describe with the help of a neat sketch.
15.
Discuss in brief the following:
(i)
Carbide tipped tools.
(ii)
Criteria used in economics in machining
(iii)
Factors upon which tool life depends.
16.
Show that the cutting speed for the maximum production rate is given by:
C/[(1- n2/n)Tr]n
Where
Tr= Tool changing time
C = constant in taylor’s tool life equation
N = Index
17.
18.
Explain the concept of machinability.
What are the various sources of heat generation in metal cutting? How is the
generated heat distributed among the chip, tool and workpiece?
19.
How are holes corrected by boring operation? Sketch a horizontal boring
machine showing various movements available on it.
20.
Describe the differential indexing method taking a suitable example.
21.
Describe the quick return mechanism of a shaper.
UNIT-3
1.
Write short notes on programme controlled turret lathes.
2.
Differentiate between automatic and semiautomatic lathe
machine. Describe a typical single spindle automatic bar type machine.
3.
Explain how transfer devices help in mass production. Explain the
working of a lift and carry type transfer mechanism.
4.
Describe a swiss type automatic and tell how it differs from the
other single spindle automatics.
5.
Discuss the importance of transfer devices in automatic
production line. Explain working of walking beam transfer mechanism.
6.
Describe the ultrasonic machining method with the help of a
sketch. Discuss effects of amplitude, frequency, type and size of abrasive, slurry concentration,
etc. on the M.R.R.
7.
Write short notes on multiple automatic machines.
8.
What do you understand by Numeric controlled machine tools?
What are their advantages and disadvantages over conventional machine tools.
9.
Discuss the importance of transfer devices in automatic
production line. Classify such devices and explain the working of a lift and carry type transfer
mechanism.
10.
What is tool layout, explain the preparation of tool layout.
11.
Sketch a flat lapping machine and describe the principle of
obtaining geometrical accuracy on the job by this process. What is the role of carrier fluid in this
process.
12.
Explain theory of grinding and derive the relationship between
force on individual grit and velocity of wheel and work piece size, wheel size and feed.
13.
Give the various types of bonds used in grinding wheels and very
briefly discuss the cases where a particular bond is used.
14.
What are the various abrasives used in grinding wheels? How a
grinding wheel is designated.
15.
Explain center less grinding machine and its limitations.
16.
Differentiate between Honing and Lapping.
17.
How is the selection of grinding wheel done depending upon the
requirement?
18.
Differentiate between natural abrasive and artificial abrasive.