Enhancing the mechanical properties and corrosion resistance of commercially pure titanium using tungsten carbide composites fabricated via additive manufacturing

Abstract

Commercially pure Ti (CP Ti) exhibits an exceptional corrosion resistance, and it is thus critical in the aerospace, marine, and petrochemical fields. However, pure Ti also displays a modest strength and limited wear resistance. Therefore, several studies have explored the incorporation of reinforcing phases, such as ceramics and carbides, leading to the development of metal matrix composites. This study investigates the fabrication of CP Ti-WC composites using an additive manufacturing process and explores the effect of the WC content on the microstructure, mechanical properties, and corrosion resistance. Regarding the mechanical properties, the tensile strength and hardness progressively increase with increasing WC content owing to microstructural refinement and solid solution strengthening caused by W. The alloy containing 5 wt% WC displays the respective maximum strength and hardness of 1042 MPa and 362.2 HV. Furthermore, WC addition enhances the corrosion resistance of CP Ti in a 70 % H2SO4 solution. Compared to those of the other samples, the alloy with 5 wt% WC exhibits the lowest mass loss (0.00242 mg/cm2) and current density in the passivation region, which are attributed to the microstructural refinement aiding in the formation of a stable oxide layer. Thus, this research highlights the potential of CP Ti-WC composites, which exhibit improved mechanical performances and corrosion resistances for use in demanding applications, with insights into microstructural control and property enhancement.