On the evaluation of uniaxial tensile and fracture properties of Ti‐6Al‐4V by spherical indentation tests with different calculation models

Abstract

This study assessed the efficacy of models in predicting uniaxial tensile and fracture properties of Ti‐6Al‐4V (TC4) alloys via spherical indentation tests (SITs). Four models, including one empirical, one numerical, and two analytical, were selected as representatives to evaluate uniaxial tensile properties. A series of experiments were conducted on TC4 alloys obtained from three manufacturing processes: selective laser melting (SLM), forging, and welding. The empirical model underestimated the material's strength, while the other models were mostly conservative, with errors within 10%, acceptable for engineering applications. However, although the incremental model is able to provide a desirable result, it may be inaccurate for calculating the yield strength. Thus, the source of errors in each model was thoroughly investigated through theoretical analysis and finite element calculations. Additionally, based on the results of optimal strength assessment, this study validated the effectiveness of the critical stress model to evaluate the fracture toughness of TC4 alloys.