Innovative experimental measurements of cutting temperature and thermal partition during Ti-6Al-4V orthogonal cutting

Abstract

Excessive machining temperature, also called overheating phenomenon, remains a significant influencing factor that determines the lifetime of aeronautics safety components. During metal cutting, the thermal partition in the different shear zones can vary, depending on kinematic process parameters and cutting edge geometry. In order to identify the temperature gradient beneath the machined surface, a new methodology has been developed with the use of a single wire thin thermocouple. Indeed, the miniaturization of the K-thermocouple allows to measure in the primary shear zone temperature. Orthogonal cutting tests are performed at several uncut chip thickness to reproduce the milling chip shape, and the impact of rake angle uncut chip thickness is underlined. Experimental results show that less than 15% of total cutting power is transferred into the machined surface with an unworn tool. This proportion decrease with the reduction of rake angle. Cutting energy in primary shear zone is hardly evacuated by the chip for thin uncut chip thicknesses.