Evaluation of the applicability of the hot ring compression test to determine the coefficient of friction in the ABNT 1045 steel machining test through statistical analysis

ABSTRACT

Friction at the tool-chip and tool-workpiece interfaces is complex, making it difficult to determine the coefficient of friction in machining processes. Thus, several tribological tests were developed to simulate the cutting conditions and determine the coefficient of friction. This work presents a comparative analysis of the coefficient of friction between ABNT 1045 steel and WC-10Co coated with AlCrN using two methods: machining test and hot ring compression test. The machining test was carried out with an oblique cut at the cutting speeds used in the test were 150 and 220 m/min. The acquisition of the signals of the machining force components by means of a dynamometer. The ring compression test was carried out at temperatures of 200 and 400 °C. Friction coefficients were obtained through a mathematicals models. The statistical analysis of the coefficient of friction showed equivalence of the coefficient of friction in the oblique machining test at a cutting speed of 150 m/min with the hot ring compression test at 200 °C. As well as in the machining test at a cutting speed of 220 m/min with the hot ring compression test at 400 °C. The macrographic analysis of the ring after deformation in the ring compression test observed the influence of the test temperature on the displacement of the neutral radius. The surface analysis of the rings and matrices of the compression test was performed using optical microscopy (OM) and roughness Ra, where an increase in roughness was observed after the test and the presence of abrasive wear.

Keywords
Coefficient of friction; hot ring compression test; machining test