The abrasive wear of sintered titanium matrix-ceramic particle reinforced composites

摘要

Particulate (TiC, TiB{sub}2 or Si{sub}3N{sub}4) reinforced Ti composites were produced by vacuum sintering (at 1400℃ for 2 h). Ti + TiC composites could be sintered to high fractional densities (> 93%), even at high TiC loadings (e.g., 40 volumepercent (vol%)). No reactions were observed to occur between the Ti and TiC. By contrast, the Ti and TiB{sub}2 and Ti and Si{sub}3N{sub}4 reacted to form composites consisting of Ti, TiB and TiB{sub}2 andα-Ti(N), Ti{sub}5Si{sub}3, Ti{sub}3Si, andTi{sub}2N, respectively. As a consequence, Ti was consumed and/or the reaction products intrinsically generated porosity during sintering. These composites were more difficult to consolidate via solid state sintering, particularly at higher volumefractions. Despite the porosity, the composites were more wear resistant (pin-on-drum abrasive wear against 100μm garnet particles) than unreinforced Ti, with the exception of the Ti + 2.5 vol% TiB{sub}2 and Ti +≤10 vol% TiC composites. The ranking ofmicrohardness and abrasion wear resistance of the composites was as follows: (hardest, most wear resistant) Ti + Si{sub}3N{sub}4 (i.e.,α-Ti(N), + Ti{sub}5Si{sub}3, Ti{sub}3Si, and Ti{sub}2N)＞＞Ti + TiB{sub}＞＞ Ti + TiC (softest, least wear resistant).The microhardness coupled with the apparent strength of the chemical interface that developed between the constituent composite phases was responsible for the observed wear behavior.