Properties of Ti-Aluminides-Reinforced Ti-Matrix Laminate Fabricated by Pulsed-Current Hot Pressing (PCHP)

Ti-aluminides-reinforced Ti-matrix composites were fabricated from 0.04 mm-thick Ti foils and 0.012 mm- and 0.024 mm-thick aluminum foils, in a process using a pulsed-current hot pressing (PCHP) equipment, and the effect of reaction temperature on properties of the composites was investigated. The composites were of laminated structure and composed of Ti and reacted layers containing Ti-aluminides. The composition of the reacted layers was dependent on the reaction temperature employed. Tensile testing at room temperature revealed that the reaction temperature was effective for the mechanical properties, including tensile strength, elongation and fracture mode, of the composites. The tensile strength and the elongation of composites fabricated at 1273 K from 0.04-mm-thick Ti and 0.012-mm-thick Al foils were 810 MPa and 3.64%, respectively, while they were 677 MPa and 3.44% for composites fabricated at 1173 K. Microstructure observations of fractured specimens showed that Ti layers of the composites fabricated at 1173 and 1273 K played a significant role in improving ductility by prohibiting the growth of numerous cracks emanating from Ti-aluminides.