State whether or not the following statements are true for orthogonal cutting, explaining your reasons: a. For the same shear angle, there are two rake angles that give the same cutting ratio. b. For the same depth of cut and rake angle, the type of cutting fluid used has no influence on chip thickness. c. If the cutting speed, shear angle, and rake angle are known, the chip velocity can be calculated. d. The chip becomes thinner as the rake angle increases. e. The function of a chip breaker is to decrease the curvature of the chip.

2 1.34 Describe the consequences of exceeding the allowable wear and (Table 21.4) for various cutting-tool materials.

21.38 As shown in Figure. 21.14, the percentage of the total cut?ting energy carried away by the chip increases with increasing cutting speed. Why?

Title It has been stated that it is generally undesirable to allow temperatures to rise excessively in... Description    It has been stated that it is generally undesirable to allow temperatures to rise excessively in machining operations. Explain why. By the student. This is an open-ended problem with a large number of acceptable answers. The consequences of allowing temperatures to rise to high levels in cutting include: (a) Tool wear will be accelerated due to high temperatures. (b) High temperatures will cause dimensional changes in the workpiece, thus reducing dimensional accuracy. (c) Excessively high temperatures in the cutting zone may induce metallurgical changes and cause thermal damage to the machined surface, thus affecting surface integrity.