Compression resistance of particle reinforced titanium matrix composites prepared by selective laser melting

Abstract

Selective laser melting (SLM) was used to prepare LaB6 particle-reinforced titanium matrix composites(PRTMCs), the influence of laser energy on the densification behavior, phase, microstructure and the corresponding mechanical properties under quasi-static and impacting conditions were studied.The results show that the densification behavior of Ti-6Al-4V alloy is changed to some extent by the introduction of LaB6 particles, and the density of PRTMCs is reduced by either too high or too low laser energy input.Significant grain refinement happens after the addition of LaB6 particles, the grain boundary of the initial β and acicular α is weakened.As a consequence, the yield stress and ultimate compressive stress of the PRTMCs are enhanced but the ductility is weakened to some extent, meanwhile, PRTMCs exhibit obvious strain rate strengthening effect.Compared with the SLMed Ti-6Al-4V, the strain strengthening effect in the plastic deformation stage and brittle fracture characteristics in the instability stage of PRTMCs become more notable.Through this study, a theoretical basis for the dynamic compressive performance of laser additive manufactured PRTMCs can be provided.

Keywords

• selective laser melting
• titanium matrix composite
• particle reinforcement
• dynamic com-pressive property