Influence of raw material selection and fabrication parameters on microstructure and properties of micro-laminated TiB2-TiAl composite sheets

Effect of various raw materials and preparation parameters on microstructure and properties of TiB2-TiAl composite sheets manufactured by hot rolling and subsequent reaction annealing of Ti-(TiB2/Al) laminates, comprising alternating Ti foils and TiB2/Al composite foils was investigated. The results showed that the microstructure and properties of TiB2-TiAl composites strongly depended on microstructure homogeneity of the starting material of Ti-(TiB2/Al) laminates, which was pronouncedly improved by increasing the TiB2 content and rapidly deteriorated when the rolling reduction was more than 70%. Therefore, the most appropriate raw material of Ti-(5 vol% TiB2/Al) laminate was subjected to hot rolling with the reduction of 65% and subsequent reaction annealing, and thus fully dense TiB2-TiAl composite sheets with desirable micro-laminated structure composing of alternating TiB2-rich layer and TiAl layer were successfully obtained and the composite sheets exhibited enhanced tensile properties at 750 °C.