Processing and microstructural characterisation of laminated Ti-intermetallic composites synthesised using Ti and Cu foils

Ti-intermetallic laminated composites were fabricated by reaction synthesis in vacuum using Ti and Cu foils. The copper layers were completely consumed due to the formation of intermetallic phases. The Ti–Cu reaction was studied by interrupting in steps the reaction process to observe the microstructural changes. Microstructural examinations using scanning electron microscopy (SEM) and X-ray microprobe analysis demonstrated that five intermetallic compounds: Ti2Cu, TiCu, Ti3Cu4, Ti2Cu3, TiCu4 were formed after heat treatment at 1173 K for 1.8 ks. Heat treatment for 18 ks resulted in a microstructure consisting of Ti and TiCu layers, but with a thick Ti2Cu interphase layer. The TiCu layers give high hardness to the composite, while unreacted titanium provides the necessary high ductility.