Three Dimensional Temperature Gradient Mechanism in Selective Laser Melting of Ti 6Al 4V

Abstract

Selective laser melting (SLM) is widely used in making threedimensional functional parts layer by layer. Temperature magnitude and history during SLM directly determine the molten pool dimensions and surface integrity. However, due to the transient nature and small size of the molten pool, the temperature gradient and the molten pool size are challenging to measure and control. A threedimensional finite element (FE) simulation model has been developed to simulate multilayer deposition of Ti6Al4 V in SLM. A physicsbased layer buildup approach coupled with a surface moving heat flux was incorporated into the modeling process. The melting pool shape and dimensions were predicted and experimentally validated. Temperature gradient and thermal history in the multilayer buildup process was also obtained. Furthermore, the influences of process parameters and materials on the melting process were evaluated.