Analytical prediction of yield strength for Ti-6Al-4V in laser powder bed fusion

In additive manufacturing (AM), material properties are directly related to the evolution of microstructures affected by processing parameters. Compared to the traditional test-and-trial and finite element analysis (FEA) approaches, physics-based analytical simulation is more cost-efficient, resource-saving, and environmentally friendly for building the processing-structure-properties relationship to rapidly predict the microstructure evolution and material properties based on the input processing parameters. Yield strength is an important property that scholars and industries attach importance to. There has not been appropriate analytical work to model this property for laser powder bed fusion or AM. In this work, several theories, including the Hall-Petch equation, mechanical threshold stress (MTS), and grain size-modified MTS models, have been employed to predict the yield strength processed. Ti-6Al-4V, a popular alloy in industries such as aerospace and medical, is utilized as the sample material for validation. The prediction accuracy of various models has also been compared with the discussion. This work provides a capstone for the analytical simulation of yield strength for AM.