A Critical Comparison of Metal-Cutting Theories With New Experimental Data

The following alloys were investigated in orthogonal metal-cutting tests at varying cutting speeds, rake angles, and feeds: Steel SAE 1112 annealed and as-received; steel SAE 1020 as-received; steel SAE 4135, annealed, as-received, and Rockwell hardnesses 27 and 35–37; aluminum alloy 2024-T4; aluminum alloy 6061 in the 0 and T6 conditions; alpha brass. The new data obtained in the present investigation under wide variation of test conditions (speed for SAE 1112 annealed and as-received was varied from 0.083–1010 fpm) confirmed earlier observations [1, 3] that the shearing stresses are independent of the test conditions investigated. These observations were supported by theoretical considerations. Correlation of metal-cutting data with compression data on the basis of the incremental or distortion-energy theory was good for the ductile metals. Less perfect correlation was observed with SAE steel 4135 and aluminum alloy 2024-T4. It was found further that none of the known theoretical angle relationships were in agreement with all of the experimental data.