Influence of cryogenic heat-treatment soaking period and temperature on performance of sintered carbide cutting tools in milling of Inconel 718

Abstract

Cryogenic heat treatment is an innovative heat treatment applied to improve the mechanical properties of sintered carbide cutting tools. In this study, the effect of cryogenic heat treatment used at different temperatures and soaking periods on the mechanical properties of carbide cutting tools was investigated. Cryogenic heat treatment was applied at two different temperatures, −145 °C and − 196 °C, for 24 and 36 h soaking periods. The microstructure of the cryogenic heat-treated cutting tool was investigated as microhardness and grain size. As a result of microstructure analysis, heat treatment soaking period was found to be more effective than heat treatment temperature. Milling tests of the Inconel 718 superalloy were performed under dry conditions using cryogenic heat-treated cutting tools and non-heat treated tools. The effect of heat treatment on cutting tool performance was studied in terms of the amount of tool wear, cutting force, surface roughness values. According to the results obtained, the cryogenic heat treatment applied to the cutting tools has a positive effect on cutting performance. In addition, in the examinations carried out on worn cutting tools, effective wear mechanisms were found to be oxidation, adhesion and abrasion.