Effects of Annealing Temperature and Aging Treatments on Microstructure, Hardness, and Wear Behavior of Ti–6Al–4V

In the present work, the microstructure, hardness, and wear behavior of the Ti–6Al–4V alloy was studied under different heat treatment conditions. For this purpose, four samples were annealed at temperatures from 800 to 1050°C for 1 h and then quenched in water and air. One of the samples was aged at 550°C for 4 hours. Microstructural investigations by optical microscopy and scanning electron microscopy demonstrated that the solution annealing at 800°C leads to a limited precipitation growth without changing microstructure and increasing hardness. By increasing the solution annealing temperature and consequently quenching in water, higher hardness was obtained along with the formation of α and α' martensite. The solution annealing at 1050°C caused the formation of the martensite phase which would be transformed to disorder the β phase; due to this phase transformation, hardness increased up to 47% compared to the hardness of the controlled sample (as receive). The n all of the samples, with or without heat treatment, the oxidative abrasion mechanism was observed along with signs of shear wear. In all of the samples, with or without heat treatment, the oxidation abrasive wear mechanism was observed along with signs of lamination wear.