Question Bank

During shaping like single point machining/turning) a steel plate at feed, 0.20 mm/stroke and

depth 4 mm by a tool of λ = γ = 0° and φ = 90° Fz and Fx were found (measured by

dynamometer) to be 800 N and 400 N respectively, chip thickness, a2 is 0.4 mm. From the

aforesaid conditions and using Merchant’s Circle Diagram determine the yield shear strength of

the work material in the machining condition?

Calculate the time taken to turn a brass component of 60 mm diameter by 84 mm long diameter

if the cutting speed is 50 m/min and the feed is 0.4 mm/rev. Only one cut has to be considered.

Neglect tool approach and tool travel

We have set up a lathe and are doing an orthogonal cut. The feed rate of the lathe is 0.1mm, and

the chip thickness after the cut is 0.2mm. The depth of the chip being cut is 5mm. The surface

cutting speed of the tool is 2m/s. The tool has a rake angle of 10deg. The tangential force is

measured as 200N, and the cutting force is 500N. a) Calculate the shear force and velocity. b)

Calculate the total energy produced in the cut, c) Calculate the energy used to shear d) Explain the

difference between the total and the shear energy.

What type of chip is expected at higher cutting speeds?

Sketch a single edge cutting tool and label the a) face, b) flank, c) nose, d) cutting edge, e) relief, f)

shank.

What factors will affect surface finish? Derive the ideal surface finish equation for a turning process

17. a) Define machinability. b) What determines the machinability of a metal?

17. a) Define machinability. b) What determines the machinability of a metal?

We are going to estimate the effects of feedrate on tool life. Some simple calculations yield the

Taylor tool life coefficients of n = 0.4 and a C = 400. Find the change in tool life (in %) when velocity

drops by a) 20% and b) 40%

What happens to the cutting process as the temperature rises?

What would happen if a drill without flutes was used?

Which of the statements about lathes below is most correct?

a) jawed chucks hold only standard sizes of pieces. b) mandrels hold work pieces from the outside. c) the chasing dial is used for measuring fine cuts. d) lead screws and feed rods are lathe parts

What type of grinding is suited to the outside surfaces for the parts below?

Explain about tool tuning in relation with chatter in machining process.

Explain the mechanism behind the Self-excited vibration.

Write short notes about criteria for Cutting Fluid Selection

Explain the role of friction in power consumption in machining process.

Write short notes about “Mitigation of Build edge formation”.

Why are ceramic cutting tools generally designed with negative rake angles?

Explain the term carbon seeking and how it affects the PCD cutting tools

Which conventional machining process consumes high specific cutting energy

Explain about the design considerations for SPDT

Explain the difference between the PVD and CVD coating process

Compare hard turning with Grinding

Write short notes about ductile regime grinding of ceramics

Explain the relationship between the cutting force with cutting velocity for High speed

machining.

Write a short note about the spindle design requirement for High speed machining

Expalin the use chip breakers in machining

What is lay pattern in a machined surface?. Indicate the lay pattern for

1. Surface Grinding 2. End Milling 3. Shaping

Taking a suitable example discuss how cutting tool wear can be mathematically modeled

using different approaches? What benefits can be achieved from such modelling?

(b) Write a note on 'tool life testing' and the success rate and reliability of the methods

used for the same.

(c) Discuss the following:

(i) Wear-Land wear.

(ii) Crater wear

Write notes on the following:

(a) Measurement of wear of cutting tools in machining.

(b) Economics of metal machining and its importance. . .

(c) Mechanics of lapping.

(d) Force system in milling operation

A HSS tool requires regrinding after 2 hours and 45 minutes when machining steel at a

cutting speed of 35m/min: Calculate the tool Iife if the speed is increased to 70m/min.

How does metallurgy of the work material and the cutting tool affect the machinability in

any machining operation?

Discuss what different types of wear can take place in cutting tool. Explain any three of

them along with the mechanism involved

Taking the optimization variables as 'specific cost' and 'production rate', describe the

procedural steps that are involved in optimizing any machining operation? Support your

answer with a suitable example.

How brittle fracture is analyzed in tools using the fracture mechanics approach.

Discuss the mechanism of grinding in detail. Also describe the cutting action of the grit

and the effect of grit force on wheel wear.

(b) How grinding wheels are tested?

(c) Mention the procedural steps required in simulating any grinding process. What

advantages are associated with it?

Using the concept of dynamometry and theoretical considerations, explain how the

following can be measured during metal cutting

(i) Force measurement.

(ii) Heat measurement.

(iii) Temperature measurement.

Discuss in detail the force system in oblique cutting. How does it differ from orthogonal

cutting?

Describe the following in relation to orthogonal cutting

(i) Shear strain.

(ii) Rate of strain.

(iii) Total energy consumed per unit volume

A cutting tool must posses the following property to enable high speed machining

a) Hardness 2) red hardness c) wear resiatnce d) hardness and toughness

b) Cast iron during machining process produces

c) a. Continuous chips b. Discontinuous chips

d) c. Continuous chips with built up edge d. Segmented chips

e) The lip angle of a single point tool is usually

f) a. 20 degree to 40 degree b. 40 degree to 60 degree

g) c. 60 degree to 80 degree d. 80 degree to 90 degree

h) Consider the following statements in respect of a grinding wheel of specifications, 51-

A-36-L-7-R-23, using the standard alphanumeric codification:

i) 1. Abrasive used in the wheel is aluminium oxide 2. The grain size of abrasive is

medium

j) 3. The wheel grade is medium hard 4. It has an open structure

k) 5. It has resinoid as bonding agent

l) Which of these statements are correct?

m) a. 1, 2 and 3 b. 1, 3 and 4 c. 2, 3 and 5 d. 1, 4 and 5

n) In orthogonal cutting, shear angle is the angle between

o) a. Shear plane and the cutting velocity b. Shear plane and the rake plane

p) c. Shear plane and the vertical direction d. Shear plane and the direction of elongation

of crystals in the chip.

Two cutting tools are being compared for a machining operation. The tool life equations are:

Carbide tool: VT1.6 = 3000

HSS tool: 6.0 VT6 = 200

where V is the cutting speed in m/min and T is the tool life in min. The carbide tool will provide

higher tool life if the cutting speed in m/min exceeds

(A) 15.0 (B) 39.4 (C) 49.3 (D) 60.0

Expalian the role of regulating wheel in centerless grinding process.

The value of chip reduction coefficient, ζ does

not depend upon

(a) cutting velocity

(b) depth of cut

(c) cutting tool material

(d) tool rake angle

During plain turning mild steel by a tool of geometry, 0°, 0°, 8°, 7°, 15°, 90°, 0 (mm) at s0= 0.2

mm/rev, the chip thickness was found to be 0.5 mm. Determine the values of cutting ratio and

shear angle in the above case.

A TAP is a cutting tool used to create which one of the following geometries

a) External threads b) Flat planar surfaces c) holes d) internal thread

Write a short note about

a) Reaming b) Boring c) Broaching

In an orthogonal cutting process v = 2.5 m.s-1, α = 6°, and the width of cut is b = 10 mm. The

underformed chip thickness is 200 µm. If 13.36 g of steel chips with a total length of 500 mm are

obtained, what is the slip plane angle? density = 7830 kg.m-3. If a toolpost dynamometer gives

cutting and thrust forces of Fh = 1100 N and Fv = 440 N, determine the percentage of the total

energy that goes into overcoming friction at the tool-chip interface and the percentage that is

required for cutting along the shear plane. (Density ρ = 7830 kg.m-3.)

A horizontal spindle surface grinder is cutting with t = 5 mm and U = 40 GPa. Estimate the

tangential force on the wheel if the wheel speed is 30 m.s-1, the cross-feed per stroke is 1.2

mm, the work speed is 0.3 m.s-1, and the wheel depth of cut is 0.05 mm.

What is flow stress in machining operation explain its importance for modeling of machining

process.

Select the process which corrects the following Errors in the cylinder bore

a) Curvature b) conicity c) barrel form d) lack of roundness e) taper f) waviness

Explain its operating principles.

Writes a short notes about a) Burn b) Residual stress in a grinding process