Microstructure and mechanical properties detecting of annealed SLM Ti–6Al–4V by laser ultrasonic center frequency offset

Abstract

In this paper, the relationship between the ultrasonic eigenvalue and the microstructure of Ti–6Al–4V titanium alloy fabricated using selective laser melting (SLM) after annealing treatment is investigated, and a relationship model correlating the ultrasonic center frequency offset with dislocation density is developed. Based on dislocation strengthening theory, models for yield strength, tensile strength, and hardness, derived from the ultrasonic center frequency offset, are further developed and validated using experimental data. The results indicate that the microstructure and mechanical property model based on ultrasonic center frequency offset achieves an accuracy of approximately 0.89.