Enhanced strength and toughness in boron nitride nanosheets/Ti composites through in-situ interfacial nano-TiBw manipulation

Abstract

Achieving intrinsic strengthening of boron nitride nanosheets (BNNSs) in Ti matrix composites was still an unsettled issue due to its severe and uncontrollable interface reaction. In the present study, high-performance BNNSs/Ti composites were fabricated by using the warm compaction (WC) technique and rapid heat treatment (HT) strategy on the basis of interfacial nano-TiB_w design. The intrinsic structure of BNNSs was well-retained and nano-TiB_w on partially reacted BNNSs led to a brilliant interface bonding and BNNSs intrinsic strengthening. Tensile tests revealed that 0.1 wt.%BNNSs/Ti composites exhibited the tensile strength (UTS) of 876 MPa (61% higher than pure Ti) and the fracture elongation of 22.6%, demonstrating the well-balanced property. By employing the in-situ TEM experiment, we solve an existing debate, uncovering the synergistic toughening effect from BNNSs and interfacial nano-TiB_w which effectively inhibited the micro-cracks propagation on BNNSs and heterogeneous interface. This work paves a new way for developing high-performance BNNSs/Ti composites by reaction interface manipulation and underscores the importance of maintaining BNNSs intrinsic structure in the Ti matrix.