Using metallic additives as a bonding layer to produce Ti-based laminated composites via spark plasma sintering

Abstract In this research work, Ti laminated composites were successfully prepared by employing metallic additive powders between Ti sheets; this was done using the spark plasma sintering process. Accordingly, Mo, Cr, Si and Co were inserted between Ti layers, and spark plasma sintering was carried out at 1250°C. Regarding the Ti-Si laminated composite, the final products comprised divided sintered Si and Ti sheets not stuck together. A new sample was prepared at a temperature higher than 1850°C with the appropriate bonding of layers. The XRD pattern of the samples cross-section revealed dominant Ti peaks in Ti-Cr and Ti-Mo; meanwhile, in the related XRD patterns, the intermetallic compounds between Ti and metallic additives of Co and Si were the dominant peaks. The FESEM images taken from the samples cross-section demonstrated the ultra-short-range diffusion of Mo into the Ti sheets. The process was amplified from Cr additives to Co; it appeared that the laminated structure was changed into a uniform one of the Ti-Co alloy. Regarding the Si additive, the laminated structure turned into the intermetallic of Ti5Si3-Ti5Si4 islands and seemed to be the composite. Studying the mechanical properties also showed the highest Vickers hardness of 1121±32 HV1 for the Ti-Si sample in terms of the intermetallic nature of the formed sample, whereas the highest bending strength of 998±16 MPa was noticed in the Ti-Cr laminated composite.