Development of Solid Lubricants Dispersed Bronze Bearing Material by P/M (Second Report) -Effects of V Addition on Sinter Densification of Cu-Sn Alloy Compacts

Abstract

In the previous paper, we reported the densification of the bronze matrix was promoted by the diffusion of Cr under solid state sintering at 1030 K. In the present work, effects of V addition on sintering properties and microstructures of the bronze matrix were investigated, and compared with Cr. Mixed powders were prepared from pulverized V powders and atomized 90Cu-10Sn powders, of which particle sizes were 106-150/an and 1-38μm respectively. Compacts pressed at 390 MPa were sintered at 670-1030 K for 0.3-180ks in H 2. V diffuses preferentially into the surface and grain boundary of the bronze powder. With increasing sintering time at 1030 K, pores of matrix decrease rapidly. This indicates that the densification of the bronze is promoted by the diffusion of V as same as the case of Cr. However, some pores are observed on the matrix and the grain size is bigger than the case of Cr after 180ks sintering at 1030K. From these results, it is assumed the effects of densification by V addition is slightly smaller than Cr.