Microstructure and tensile behavior of novel laminated Ti-TiBw/Ti composites by reaction hot pressing

摘要

A novel laminated Ti-TiBw/Ti composites composed of Ti layers and TiB whisker reinforced Ti (TiBw/Ti) composite layers were successfully fabricated by reaction hot-pressing. Herein, the TiBw/Ti composite layers were in situ synthesized by reaction in the system of Ti and TiB_2 powders during the hot pressing process. The composite layer can effectively refine grains of Ti layer. Moreover, in-situ synthesized TiB whiskers obviously restrain the growth of Ti matrix grains of the TiBw/Ti composite layers. It is worth pointing out that the in situ synthesized TiBw can strengthen the interface between Ti layer and TiBw/Ti layer. The tensile testing results show that the ultimate strength and the ductility of laminated composites can be increased to 617 MPa and 20.5%, respectively, from 546 MPa and 17.5% of pure Ti, indicating that the strengthening effect and the toughening effect of the composites were effectively exploited by tailoring the novel laminated structure of Ti-TiBw/Ti composites.