Titanium alloys have poor wear resistance, tend to adhere during sliding, and exhibit high friction, which limits their use in parts subject to friction and wear. Using the strong mechanical and self-lubricating properties of boron nitride nanoplatelets (BNNP) and the layered structure of plasma-sprayed coatings, this work fabricates a BNNP-reinforced Ni₃Al composite coating on TC4 titanium alloy, based on the idea that interfacial reactions between BNNP and the Ni₃Al matrix strengthen bonding both within and between splats. Instrumented micro-scratch tests show the friction coefficient arises mainly from plowing and adhesion; BNNP slightly lowers the plowing component and, through its lubricity, forms a film between indenter and coating that greatly reduces the adhesion component. Sliding wear tests show the Ni₃Al coating itself improves the wear resistance of TC4, and adding BNNP further lowers the friction coefficient and wear rate while reducing wear on the counter-ball. The BNNP/Ni₃Al composite coating exhibits excellent wear resistance and low friction at both room temperature and 800°C, demonstrating strong potential for titanium alloy components operating under high-temperature friction and wear conditions.

Plasma Spray,Tribological properties,Mechanical Properties,Boron Nitride Nanoplatelet