In-situ dual-deoxidation design of advanced titanium matrix composites by pressureless sintering

Abstract

We establish a methodology of in-situ dual-deoxidation to fabricate advanced titanium matrix composites (TMCs) by pressureless sintering (PLS). Specifically, the in-situ dual-deoxidation of impurity O in Ti matrix was designed as the in-situ formation of H2O and La2O3 particles, which was accomplished by PLS of advanced TMCs from powder mixtures containing Ti–6Al–4V matrix of TiH2 and 60Al40V together with LaB6 addition. Interestingly, the advanced TMCs with in-situ La2O3 particle and TiB whisker have various merits, including the significantly reduced O content in the Ti matrix, the refined equiaxed α-Ti grain with monolayer nanosized L phase grain boundary, and especially the nearly full-density evading Kirkendall's pore. Resultantly, the advanced TMCs circumvent the strength–ductility trade-off of representative Ti–6Al–4V TMCs by various materials processing methods. Our results provide a novel strategy for fabricating cost-effective advanced TMCs by PLS to yield superior mechanical properties.