Fabrication and characterization of laminated Ti-(TiB+La2O3)/Ti composite

Abstract

The incorporation of ceramic particulate reinforcements into titanium alloys can improve the specific strength and specific stiffness, while inevitably reduce the plasticity and ductility. In this study, in situ synthesized multilayer Ti-(TiB+La2O3)/Ti composite was designed by learning from the microstructure of nature biological materials with excellent mechanical properties. The Ti-(TiB+La2O3)/Ti composite with unique characteristic of laminated structure was prepared by combined powder metallurgy and hot rolling. The method has the synthesize advantages with in-situ reaction of Ti and LaB6 at high temperature and controllability of reinforcements size and constituent phases in composites. The result shows that the pores in the as sintered laminated structure composite completely disappeared after hot rolling at 1050°C. The agglomerated reinforcement particles were well dispersed and distributed uniformly along the rolling direction. The thickness of pure Ti layer and (TiB+La2O3)/Ti composite layer decreased from 1mm to about 200μm. Meanwhile, the grains size was refined obviously after rolling deformation. The room temperature tensile test indicates that the elongation of the laminated Ti-(TiB+La2O3)/Ti composite improved from 13% to 17% in comparison with the uniform (TiB+La2O3)/Ti composite, while the tensile strength had little change. It provides theoretical and experimental basis for fabricating the novel high performance laminated Ti-(TiB+La2O3)/Ti composites.