Titanium alloy based dispersion-strengthened composites

摘要

Titanium based metal matrix composites reinforced with ceramic particulate are well known, based on a blend of titanium alloy powders with ceramic powders, e.g., aluminum oxide powders, utilizing a low energy ball milling process, followed by cold compacting and sintering to produce an appropriate composite. This prior art process is disadvantaged from the point of view that there are virtually no particles in the blend below the micrometer size range, which lack has a deleterious effect on the subsequent processing of the composite. This problem has been overcome by utilizing dry high energy intensive milling in the process, which has the effect of providing the necessary number of small particles below the micrometer size range as well as enhancing the reactivity of different particles with one another. In order to produce a titanium base alloy alumina metal matrix composite, titanium dioxide powder is blended with aluminum powder and subjected to dry high energy intensive milling until the separate particle phases achieve a size of 500 nanometers maximum. The intermediate powder product is then heated to form the titanium alloy/amumina metal matrix composite in which the ceramic particles have an average diameter of no more than 3 mu, and the oxide consists of more than 10% and less than 60% by volume fraction of the total composite. The composites have extensive application to tough and strong engineering alloys.