Investigation on preparation, microstructure, and properties of AgTiB2 composite

Abstract

AgTiB2 composites with different contents of TiB2 were prepared by high-energy milling and powder metallurgy. The morphology and size of the milled Ag/TiB 2 compound powders were characterized by a scanning electron microscopy and a laser particle analyzer. The effect of sintering temperature and TiB 2 content on the microstructure and properties of AgTiB2 composite was studied. The results show that: (1) with increase of the milling time, the powders become finer and more uniform. Nevertheless, the powders begin to coarsen and agglomerate above a certain milling time. In the range of experiments, the desired powders with a relative uniform size can be obtained at 60 h; (2) the increase in TiB2 content results in serious agglomerations of TiB2 in the AgTiB2 composites; and (3) the Ag—0.25 wt%TiB2 composite has a good combination of properties after sintering at 750° C for 2 h, and the hardness and electrical conductivity are 73.3HV and 17.8 MS m-1, respectively.