MANUFACTURING PROCESS AND MECHANICAL-PROPERTIES OF FINE TIB DISPERSEDTI-6AL-4V ALLOY COMPOSITES OBTAINED BY REACTION SINTERING

Fine TiB dispersed Ti-6Al-3V alloy composites were developed using a p owder metallurgy method, in which high hardness, high strength,high we ar resistance and superplasticity were expected. Boride powder (i.e. T iB2), MoB, CrB and Ti-6Al-4V prealloyed powder were mechanically blend ed in a high energy ball mill. The powder obtained was pressed into di es and consolidated by reaction sintering. The dispersed boride partic les produced reactive TIE in the matrix during sintering. In the hot i sostatic press (HIP) which followed, samples showed a very fine micros tructure of TiB dispersing homogeneously. At room temperature, hardnes s, compressive strength and wear resistance had the tendency to increa se as blended boride content increases. The results of compressive and tensile test at 1173 K, in the strain rate range of 1 x 10(-3)-1 x 10 (-4) s(-1), showed that TiB dispersed composites exhibited m values of no less than 0.38 and large elongation and superplasticity was confir med. (C) 1998 Elsevier Science S.A. All rights reserved.