Fabrication of a multiscale structure in Ti₅₀Zr₃₀Nb₁₀Al₁₀ refractory multi-principal element alloy: Wear mechanism studies at room and elevated temperatures

TiZr-based refractory multi-principal element alloys (RMPEAs) have attracted significant attention due to their excellent comprehensive properties. Although notable progress has been made in enhancing the mechanical properties of alloys through multiscale design, the influence of such design on wear resistance remains unclear. In this work, a multiscale-strengthened lightweight (Ti₅₀Zr₃₀Nb₁₀Al₁₀)₉₇B₃ RMPEA was fabricated through combining plasma atomization, spark plasma sintering, and aging treatment, which shows enhanced wear resistance. The enhanced room-temperature tribological performance is primarily attributed to the wear deformation resistance provided by multitype-multifunctional strengthening phases: the α2 phase accommodates deformation via bending and orientation mismatch, while the B2 phase suppresses dislocation transmission to greater depths by annihilating interfacial dislocations through amorphization. At 600 °C, the wear rate of the optimized alloy is 3 × 10⁻⁵ mm³/(Nm), approximately two orders of magnitude lower than that of the unoptimized alloy. This improvement is primarily attributed to the protection effect of the high-hardness tribo-layers and the synergistic strengthening-deformation coordination of the multiscale structure.