Metal Cutting Theory

Problems

Problem 1

• The following data are available from orthogonal cutting experiments.

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• In both cases, depth of cut (feed) to = 0.13 mm, width of cut w = 2.5mm, rake angle = −5, and cutting speed V=2 m/s. Determine the shear angle, friction coefficient μ, shear stress and shear strain on the shear plane, chip velocity Vc and shear velocity Vs, as well as energies uf , us and ut.

Solution

• Sol:- – First, consider the aluminum workpiece, where • tc = 0.23 mm, Fc = 430 N, Ft = 280 N,• to = 0.13 mm, w = 2.5 mm, α= −5 and• V = 2 m/s.

• Now we know

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• Also

• So • φ = 28.2 degrees.

• the coefficient of friction is given by

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Problem 2

• In a dry cutting operation using a −5 degrees rake angle, the measured forces were Fc=1330N and Ft = 740 N. When a cutting fluid was used, these forces were Fc = 1200 N and Ft = 710 N. What is the change in the friction angle resulting from the use of a cutting fluid?

Solution

• Sol:-• For friction angle

Solution (Continued..)