Microstructure and mechanical properties of Ti-aluminides reinforced Ti matrix composites synthesized by pulsed current hot pressing

Ti-aluminides reinforced Ti matrix composites were fabricated by a pulsed current hot pressing technique, in that a combustion synthesis reaction occurs at the interface between Ti and Al foils. This reaction causes the formation of multi layered Ti-aluminides between Ti foils, and these Ti and Ti-aluminides were densified and bonded to each other. The composites thus fabricated were of alternately laminated structure. With increasing the thickness of Al foils used, the thickness of Al3Ti layer formed in Ti-aluminides increased. These composites became strong in tensile strength at room temperature, which is related to the thickness of the Al foils. The tensile strength and the elongation of a composite produced from 0.04 mm thick Ti and 0.012 mm thick Al foils was about 700 MPa and 3.5%, respectively, while they are about 420 MPa and 2.6% for a composite produced from 0.04 mm thick Ti and 0.024 mm thick Al foils. This good ductility of the composite is considered to prevent the propagation of numerous cracks emanating from the Ti-aluminides when reaching Ti layers.