Question Paper of METAL CUTTING for M.Tech (PE) (Sem.- 1st), Paper ID [ E0442 ], PTU Question Paper.

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Roll No…………….

Total No. of Questions: 08

M.Tech (PE) (Sem.- 1^st)

METAL CUTTING

Subject Code: PE-502

Paper ID: E0442

Time: 3 Hrs.                                                                 Max. Marks: 100

Instruction to Candidates:

1)    Attempt any five questions out of eight.

2)    Each question carries TWENTY marks.

Q1)

(a)  What are the various mechanisms of chip formation during maching of mild steel?

(b) Explain the concept of shearing strain for chip deformation.

Q2)

(a)  A metal cutting test results indicates that for a given operation the optimum rake should be 10⁰. For convince of chip flow a 2-3⁰of inclination angle is recommended. What is the back rake and side rake of this tool, if principle cutting edges angle is 60⁰?

(b) Explain the effect of cutting variables on chip reduction coefficients.

Q3)

(a)  A tool shape with 6⁰ back rake and 55⁰ side cutting edge angle has to be used under orthogonal cutting conditions. The cutting forces are F_z=260kg and F_xy=190 kg. The cutting velocity is 90m/minute Calculate.

(a)  The necessary side rake angle so that cutting is orthogonal

(b) The kinetic coefficient of friction

(c)  Energy consumed in friction per unit volume of metal removal if  the chip reduction coefficient is 2.75.

(d) Explain the construction and working of four component strain gauge type drill dynamometer.

Q4) 

(a)  Derive an expression for thrust force at the chisel edge  zone of a twist drill.

(b) Estimate the cutting components of the machining force during the orthogonal machining of an aluminium alloy with an uncut thickness of 0.15mm, width of  cut being 2.5 mm.

Q5)

(a)  What are the various heating teachniques in hot working process? Discuss the  advantages and disadvantages over each other.

(b) Explain the term “Form Stability” at low cutting speed.

Q6)

(a)  Explain the mechanism of tool wear during machining process. Compare the  wear characteristics of conventional cutting tool materials.

(b) What do you mean by the economics of metal cutting ? Derive an expression for  optimum cutting speed for maximum production rate. Assume suitable assumptions.

Q7)

(a)  Derive an expression for maximum grit chip thickness during grinding process.

(b) Explain the effect of temperature during grinding process.

Q8) Write short note on the followings:

(a)  Diffusive wear model

(b) Lapping and Honing process