Cellular Automata Analysis of Effects of Substrate Conditions on Microstructure and Texture Evolution during Selected Laser Melting

A Cellular Automata Finite Difference (CAFD) method was applied to analyze the effects of substrate grain size and texture on the microstructure and texture evolution during additive manufacturing. It was found that the grain size within the substrate is only effective at a short distance. Grains developed from the surrounding powders can lead to an almost similar microstructure away from the substrate. Texture evolution during build-up can be explained by the two main components of {001} and {011} . Development of the former and the latter components can be described by the competitive growth mechanism at the regions beneath and on the sides of the melt-pool, respectively. As a result, the former component is more pronounced at the higher ratios of the melt-pool width to the hatch distance. An almost similar fiber texture can develop from a substrate with the fiber texture of {001}||build-direction (BD). However, a substrate having the fiber {011}||BD evolves into the component {011} , implying that other components of this fiber are not favored. In either case, due to the highly elongated melt-pool, the orientation {001}||hatch-direction (HD) is preferred and {011}||HD is not likely to happen.