Configuration design and fabrication of laminated titanium matrix composites

The introduction of particulate reinforcements into titanium alloys can improve the strength and stiffness, but it generally results in unsatisfactory plasticity and ductility. In this study, in situ synthesized multilayer titanium matrix composites were designed and fabricated by learning from the microstructure of nature biological materials with attractive mechanical properties. Laminated Ti-(TiB + La2O3)/Ti composites with different reinforcement volume fraction were fabricated through powder metallurgy, followed by hot rolling process. The results show that pore defects, TiB whisker and large La2O3 particle agglomerates can be observed in the composites after vacuum sintering at 1573 K, further the pores are disappeared and the grains are refined significantly after hot rolling at 1323 K. Meanwhile, the reinforcements agglomerates are well dispersed and distributed uniformly along the rolling direction. The tensile testing results indicate that the Ti-10 vol.% (TiB + La2O3)/Ti composite shows promising mechanical properties due to the configuration design of laminated structure, which results in an improvement of 30% in elongation with <4% decline in tensile strength compared with 5vol.% (TiB + La2O3)/Ti composites. Moreover, further increase in reinforcement volume fraction leads to slight increase in tensile strength and significant decrease in elongation due to the increasing of large Ia(2)O(3) agglomerates. (C) 2016 Elsevier Ltd. All rights reserved.