Study on the influence mechanism of internal strain on wide-temperature range tribological behavior of Ti6Al4V alloy

Abstract

Rolled titanium alloys exhibit significant internal strain, adversely affecting mechanical performance. This study examines how internal strain influences the frictional behavior of Ti₆Al₄V across a broad temperature range. To alleviate strain, Hot Isostatic Pressing (HIP) was applied. HIP transformed the microstructure by restoring substructures and promoting recrystallization, reducing hardness by ∼ 10 %. However, reduced strain suppressed crack initiation and propagation, preventing the formation of large-sized wear debris. Post-HIP, smaller wear debris with high surface energy promoted a high-temperature oxidation layer, enhancing wear resistance at elevated temperatures. These findings provide insights into the role of internal strain in titanium alloy tribology and demonstrate HIP's effectiveness in improving high-temperature wear resistance.