Comparative analysis of the tool life of submicron hard alloy WC-10Co sintered from powder obtained by electro discharge in oil

Abstract

In this paper, comparative studies of the microstructure, mechanical characteristics and service life of a cutting insert made of submicron cemented carbide WC-10Co, obtained as a result of recycling VK10 cemented carbide by Electro Discharge Erosion (EDE) in oil, were carried out. The specific energy consumption directly for the formation of pulses in the process of EDE is to a relatively small value (5.7 kW·h/kg). Excess carbon formed as a result of oil pyrolysis during EDE was removed by heat treatment. The granulometric composition of the obtained powder and the microstructure of the particles were studied. It is shown that the particles of the resulting powder consist of plate-like WC grains with an average diameter of 0.46 pm and interlayers of cobalt. The WC-10Co cutting insert, obtained by sintering this powder in vacuum, was used for a comparative analysis of service life during fine turning of aluminum alloy D16T. As objects for comparative analysis, cutters equipped with blades made of industrial alloys VK8 and VK6OM of a similar design were used. The microstructure and mechanical characteristics of the experimental alloy and the analogues presented have been studied. On the basis of studies of the microstructure and chemical composition of the back surface of the cutting inserts, the wear mechanism of the cutters was analyzed. It is shown that the hardness of the alloys has the main effect on their wear resistance when cutting an aluminum alloy with the presented cutters. The influence of the hardness of the cutters on the surface roughness of the resulting part was also studied. The obtained submicron cemented carbide WC-10Co exhibits the highest hardness (1590 HV) and wear resistance of the presented samples due to the smallest WC grain diameter (0.59 pm).