Achieving BNNSs intrinsic strengthening in Ti-based composite through reaction-interface engineering

For the purpose of achieving boron nitride nanosheets (BNNSs) intrinsic strengthening and relating microscopic interface characteristics to macroscopic mechanical behavior in BNNSSs/Ti composites, the BNNSs/Ti composites were fabricated by field-assisted hot pressing (FHP) and subsequent 923K, 1023K, 1123K or 1223K hot-rolling (HR). Herein, we succeeded in simultaneously maintaining the BNNSs intrinsic structure and considerable interfacial nano-sized TiB_w. Interestingly, the superior tensile property (UTS: 1166 MPa, El. 9.3 %) was realized in 1123K as-rolled BNNSs/Ti composite, whereas the dramatic ductility deterioration exhibited in composite when the HR temperature setting at 1223K. BNNSs load transfer and interface failure behavior were investigated by direct in-situ tensile SEM observation. The nano-TiB_w on partially reacted BNNSs played a predominant role on BNNSs load-transfer efficiency and contributed to the desirable ductility. These findings highlighted the untapped potential for improving mechanical properties in BNNSs reinforced metal matrix composite.