Thermal Behavior and Densification Mechanism during Selective Laser Melting Additive Manufacturing of Metal Powder

Abstract

Herein, based on the ABAQUS commercial finite‐element analysis (FEA) software, a set of user subroutines is designed, and then a 3D FEA model is proposed to systematically and quantitatively investigate the effects of laser processing parameters on the evolution of molten pool structure and complicated thermal behavior during the selective laser melting (SLM) additive manufacturing of H13 die steel. The SLM experiments are conducted to verify the accuracy and reliability of simulation and reveal the densification behavior of SLM‐fabricated H13 die steel parts. The underlying thermal mechanism is revealed, and the relationship among laser processing parameters, thermal behavior, and densification is established. It is found that the densification behavior is highly sensitive to the applied volume energy density (VED). The densification level is effectively controlled by adjusting VED, hence obtaining the parts with excellent performance. The SLM‐fabricated specimens with nearly full dense cross sections are obtained, as the applied VED increases to 111 J mm−3. Research results found herein lie a foundation for the actual SLM processing of H13 die steel and provide a theoretical basis and technical support for the laser rapid prototyping of other die steels or even complete die parts.