Micro milling of tungsten-copper composite materials produced through powder metallurgy method: Effect of composition and sintering temperature

Abstract

Each passing day, materials are produced with different compositions by the method of powder metallurgy. The machinability of the produced materials is as important as the mechanical and chemical properties. In aforesaid article, cutting force variations, tool wear, surface roughness and burr formation during the micro milling of W-Cu alloys in different content sintered at 2 different temperatures were investigated. Significant amount of characterization study has been done and different measuring systems (like dynamometer, SEM, roughness measurement, surface profilometer) and software are used. The effect of the selected sintering temperatures on the microstructure are shown by SEM photographs, and then, effects of these temperatures on cutting force, tool wear, surface roughness and burr formation, which are caused by compositions with different Cu contents, are discussed. According to the obtained results, high sintering temperature and high tungsten ratio have been increased hardness values of samples. For this reason, tool wear in micro milling of W-%10wtCu sample sintered at 1100ºC is the maximum level. In addition, the sintering temperature and tungsten ratio significantly affect the cutting forces and surface roughness. As a result of abrasive wear mechanism, deterioration in tool geometry causes increasing of cutting forces, deterioration of surface quality and burr formation.