Difficulty: Easy
Correct Answer: all of these
Explanation:
Introduction / Context:
The shear angle governs chip thickness, cutting force, and temperature in metal cutting. Understanding what affects it enables better selection of feeds, tool geometry, and cutting strategy for surface finish and productivity.
Given Data / Assumptions:
Concept / Approach:
According to classic cutting mechanics (e.g., Merchant-type relations), shear angle depends on geometry and deformation, notably the rake angle, uncut chip thickness (set by feed and depth), and friction. Chip thickness ratio directly reflects shear angle. Thus feed (which sets uncut chip thickness), measured chip thickness, and rake all influence the shear angle.
Step-by-Step Solution:
True feed increases uncut chip thickness → affects chip thickness ratio → alters shear angle.Measured chip thickness is related to shear angle via chip ratio r = t1 / t2 → changes in r shift shear angle.Increasing positive rake tends to increase shear angle, lowering cutting forces.
Verification / Alternative check:
Experimental plots show shear angle rising with increased positive rake and decreasing with increased friction or higher chip thickness ratios.
Why Other Options Are Wrong:
Any single factor alone is incomplete; lubrication (E) influences friction and thus shear angle indirectly, but the primary listed parameters (A, B, C) explicitly govern chip geometry and mechanics.
Common Pitfalls:
Ignoring that feed changes both force and heat via shear angle; assuming shear angle is fixed for a given material.
Final Answer:
all of these
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