Assessment of Chip Thickness Ratio for Optimal Shear Angle in Machining Special Grade Steel

Abstract

Shear angle plays a crucial role in establishing machining precision, tool life, minimal metal deformation, and reduction in cutting resistance. This research focuses on estimation of shear angle in two-dimensional machining of special steel grade. The input variables considered were cut depth, feed rate, and machining speed, while the dependent characteristics were chip thickness ratio and shear angle. Pearson product moment correlation coefficient was employed for analysis. Machining tests were conducted on the lathe and orthogonal forces were measured. Based on experimental data, chip thickness ratio and shear angle were evaluated. Outcomes from the study show that the minimum and maximum shearing inclination was 12.8 degree and 44.3 degree, respectively. Investigation show that the best combination of speed, cut depth and feed rate for optimal shear angle 25.14⁰ was 0.4 mm/rev, 101 m/min, and 0.9 mm, respectively. Optimal shearing inclination occurred at a chip thickness ratio of 0.42mm, and the cutting force was 313N. More so, the correlation coefficient between the optimal shear angle and chip thickness ratio was observed to be 1, which indicates a strong relationship between both machining parameters. In metal cutting, with proper combination of cutting conditions, tool geometry and chip thickness ratio, optimal shear angle can be obtained for minimum cutting forces and maximum productivity.