Numerical modelling and microstructural evolution of hybrid Ti-6Al-4V/Ti-Al-Si-Cu composite coating

Additive manufacturing is a commercially competitive manufacturing technique with the possibility of altering the entire perception of design and fabrication. It offers suitable capabilities for the building and repairing applications in the aerospace industry, which usually requires high level of accuracy and customization of parts which usually use materials known to pose difficulties in fabrication such as titanium alloys. The major factors that determine the formation of the dendritic structure are the thermal gradients within the substrate during cooling and the cooling rates. The rapid cooling and input of heat locally during the laser deposition process resulted in metallurgical modifications such as the formation of a complete martensitic structure, a mixture of columnar grains and layer of bands. During the deposition process, the metal solidified, and the developed model enabled predictability of microstructural development and the sizes of the grain growth. The 3D numerical investigation provided clarification and had substantial effects in the prediction of the overall resulting molten pool size and geometry size.