Surface morphology and effect of cutting force and temperature in formation of the white layer during hard machining

Abstract

In hard machining, different tribological phenomenon occur, out of which white layer formation and surface characterization are an important aspect. The white layer is found to be harder and fragile. It may cause a crack and may lead to failure in machined parts. Here, an experimental work is conducted in machining hardened AISI D2 steel. Cutting speed, feed, and depth of cut are taken as the input parameters. The level of each parameter is two. The white layer development process considering the impact of cutting force, temperature and morphology of hardened surfaces, etc. are covered in the study. The study of white layer morphology and hardness are carried out with FESEM and microvicker's tester. The parametric study reveals occurrence of white layer due to the cutting force and temperature. Temperature has an important effect in increasing the surface hardness due to which the thickness of white layer changes. ANOVA analysis showed that cutting speed is the influencing variable for white layer thickness and microhardness, whereas depth of cut is influential for temperature, flank wear and cutting force.