Simultaneous Enhancement of Strength, Ductility and Wear Resistance of Tc4 Matrix Composites Via Boron Nitride Incorporation

Abstract

BN-strengthened TC4 composites were synthesized through a combined process of ball milling and spark plasma sintering (SPS). The investigation systematically characterized the microstructural evolution, tensile behavior, and tribological performance of the composites as a function of BN addition. Experimental results demonstrated that BN decomposed into boron (B) and nitrogen (N) during the sintering process. B atoms reacted in situ with the matrix to form TiB whiskers (TiBw), while N atoms were incorporated into the matrix, enhancing its strength through solid solution strengthening. Notably, the composites with 0.15 wt% BN exhibited an exceptional strength-ductility synergy (1240 MPa/14.7%), achieving simultaneous enhancements in both strength and ductility relative to pure TC4 and surpassing the mechanical properties of previously reported TC4 composites in the literature. The superior mechanical performance of the composites results from a synergistic combination of grain refinement strengthening, solid solution strengthening, and load transfer mechanisms. In addition, the composites exhibited markedly enhanced wear resistance in comparison with the pure TC4 alloy. This study proposes an effective strategy for developing titanium matrix composites with improved strength, ductility, and wear resistance for advanced engineering applications.

Keywords: Titanium matrix composites, Boron nitride nanosheets, Mechanical properties, Strengthening mechanisms