The effect of processing parameters on the molten pool dynamics during laser powder bed fusion of CuCrZr/316L multi-material

Abstract

The multi-material components formed by laser powder bed fusion (LPBF) have shown potential in advanced equipment due to their superior performance. The uneven distribution of immiscible in the molten pool is a challenge for the performance of multi-material components. In this study, a thermo-fluidic particle scale numerical model coupled with a ray-tracing method is established to understand the formation of the immiscible CuCrZr/316L multi-material. The impact of process parameters on the distribution of CuCrZr and 316L is investigated. Results reveal that the experimental and simulation results agree well with a maximum molten pool width and depth difference of 7%. The recoil pressure and Marangoni convection contribute to the mixing of 316L and CuCrZr. As the scanning speed decreases or the scanning power increases, a longer molten pool lifetime is obtained, which increases the immiscible CuCrZr/316L mixing. A large number of CuCrZr islands are formed inside the molten pool at high energy density with improved homogeneity. This work can provide fundamental insights into understanding the distribution of immiscible metal material in the multi-materials LPBF process.

Keywords

• Laser powder bed fusion
• Copper/steel multi-material
• Molten pool dynamics
• Computational fluid dynamics model
• Ray tracing