Mechanical behavior of damage tolerant TiB whisker-reinforced in situ titanium matrix composites

Abstract

The results of a systematic study of the effects of alloying and microstructure on the mechanical behavior of in situ titanium matrix composites are reported in this paper. In situ composites are produced by alloying with B which promotes the formation of TiB whiskers during rapid solidification processing. The composite powders are subsequently compacted and extruded to align the whiskers prior to systematic heat treatment in the β and/or α + β phase fields. The processing conditions for the development of in situ composites with attractive combinations of strength, ductility, damage tolerance and creep resistance are thus established. The improvements in the composite properties are rationalized using simple micromechanics principles. The paper highlights the potential for the microstructural design of composites using micromechanics and conventional physical metallurgy principles.