Manufacturing Processes for Engineering Materials by Steven R. Schmid Serope Kalpakjian | 9788131705667 | 8131705668 | Holooly

Manufacturing Processes for Engineering Materials [EXP-50967]

59 SOLVED PROBLEMS

Question: 9.3

Action of a grinding wheel A surface-grinding operation is being carried out with the wheel rotating at a constant spindle speed. Will the wheel act soft or act hard as it wears down over a period of time?

Verified Answer:

Referring to Eq. (9.6), Relative grain force [lat...

Question: 4.2

Adhesive wear in sliding The end of a rod made of mild steel is sliding over the unlubricated surface of hardened tool steel with a load of 100 kg. The hardness of mild steel is 150 HB. What is the distance traveled to produce a wear volume of 1 mm^3 by adhesive wear of the mild steel rod?

Verified Answer:

The parameters in Eq. (4.6) for adhesive wear are ...

Question: 10.5

Analysis of a plastic extruder An extruder screw with a thread angle of 20° has a melt-pumping zone that is 1 m long, with a channel depth of 7 mm for a 50-mm-diameter barrel. The screw is used to extrude 5-mm-diameter circular nylon bars through a die with a 20-mm land length at 573 K. If the

Verified Answer:

Note from Fig. 10.12 that the viscosity of nylon a...

Question: 6.3

Back tension required to cause slip in rolling It is to be expected that in rolling a strip that if the back tension, sb, is too high, the rolls will begin to slip. Derive an expression for the magnitude of back tension required to make the rolls begin to slip.

Verified Answer:

Slipping of the rolls means that the neutral point...

Question: 10.6

Blown film Assume that a plastic shopping bag, made from blown film, has a lateral (width) dimension of 300 mm. (a) What should be the extrusion die diameter? (b) These bags are relatively strong. How is this strength achieved?

Verified Answer:

(a) The perimeter of the bag is (2) (300)= 600 mm....

Question: 8.6

Calculation of material-removal rate, power required, and cutting time in face milling Refer to Fig. 8.54, and assume that D = 160 mm, w = 70 mm, l = 450 mm, d = 3 mm, v = 0.5 m/min, and N = 120 rpm. The cutter has 10 inserts and the workpiece material is a high-strength aluminum alloy. Calculate

Verified Answer:

The cross section of the cut is

wd

...

Question: 7.1

Calculation of maximum punch force Estimate the force required in punching a 30-mm diameter hole through a 3-mm thick annealed aluminum-alloy 6A1-4V sheet at room temperature.

Verified Answer:

The force is estimated from Eq. (7.4),

F_{m...

Question: 2.3

Calculation of modulus of resilience from hardness A piece of steel is highly deformed at room temperature. Its hardness is found to be 400 HB. Estimate the modulus of resilience for this material.

Verified Answer:

Since the steel has been subjected to large strain...

Question: 2.1

Calculation of ultimate tensile strength A material has a true stress–true strain curve given by σ = 689,655ε^0.5 kPa Calculate the true ultimate tensile strength and the engineering UTS of this material.

Verified Answer:

Since the necking strain corresponds to the maximu...

Question: 6.1

Calculation of upsetting force A cylindrical specimen made of annealed 1112 steel has a diameter of 200 mm and is 125 mm high. It is upset, at room temperature, by open-die forging with flat dies to a height of 50 mm. Assuming that the coefficient of friction is 0.2, calculate the upsetting force

Verified Answer:

The average-pressure formula, from Eq. (6.18), is ...

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