Microstructure and mechanical properties of Cu–Fe-ZTA cermets prepared by vacuum hot pressing sintering

Abstract

Cermets with Cu and Fe as matrix and zirconia toughened alumina (ZTA) as reinforcement phase were prepared by vacuum hot pressing sintering. Electroless Ni plating was carried out on ZTA particles to improve the interfacial bonding ability between ZTA and metal matrix. Cu-xFe-ZTA cermets (x = 20, 50, 80) were prepared by using different proportions of Cu powders and Fe powders as the binder in order to investigate the influence of binder types on the grinding performance of cermets. The phase composition, microstructure, mechanical properties and grinding properties of Cu–Fe-ZTA cermets were systematically studied. It revealed that the difference of cermet grinding performance lay in the bonding force between metal matrix and abrasive. The coating ability of abrasive is stronger with the increase of Cu content in the matrix. Because the matrix is soft and easy to grind, the cermet grinding wheel material has strong self-sharpening, and Cu–20Fe-ZTA grinding effect is the best. The friction coefficient of Cu–20Fe-ZTA cermets was 0.405, the grinding surface roughness was 7.972 μm, and the residual stress σx and σy were 180.5 and 89.6 MPa, respectively. As the Fe content decreased, the grinding mechanism changed from ploughing and cutting to friction.