Improving the accuracy and reliability of temperature field simulation during laser metal deposition

Laser metal deposition (LMD), as a major metal additive manufacturing (AM) process, features complex thermal history. The local temperature field, which varies with location and time, plays a vital role in affecting the microstructure and mechanical properties of the final product. This study develops a robust numerical model based on finite element analysis (FEA) to determine the temperature field in an accurate and reliable way. Taking a titanium alloy as an example, the melt pool geometry is used to select the best heat source model and key thermal parameters. Temperature measurements underneath the melt pool using thermocouples are employed to quantify the location-dependent heat convection model by comparing the thermal history. Some strategies for further refinement of this numerical model are also discussed in this paper. This improved numerical model is expected to provide a solid ground to support reliable simulation of microstructure and mechanical properties for the LMD process.