Microstructure distribution and orientation-structure topology optimization of metallic materials for laser additive manufacturing

The type and distribution of microstructure of metallic materials in laser additive manufacturing have an important influence on the overall mechanical properties, and how to control the location distribution of microstructure rationally through topology optimization to improve the mechanical properties of the part is one of the research focuses. In this paper, we propose a method of microstructure distribution and orientation-structure topology optimization (MDOSTO) for laser additive manufacturing. This method obtains the position distribution of the microstructure of columnar and equiaxed grains under a macroscopically optimised design. Based on the anisotropy of columnar crystals and the isotropy of equiaxed grains to obtain a microstructure with alternating grains distribution for optimal mechanical properties. The flexibility is compared with the structure of disordered grain distribution by two arithmetic examples (Miniature binding beam and Cantilever Beam), and the flexibility is reduced by 26.3% and 26.6%, respectively, which verifies the feasibility and effectiveness of the method. This method makes full use of the properties of different microstructures to improve the mechanical properties of the part.