Modeling and Experimental Investigation of Pre-Mixed Multi-Powder Flow in Fabricating Functional Gradient Material by Laser Metal Deposition Process

Laser Metal Deposition (LMD) is an effective process to fabricate Functionally Gradient Material (FGM) from pre-mixed powders. Since the supplied multi-powder directly affects the deposited FGM’s composition, investigation on Pre-Mixed Multi-Powder (PMMP) flow during LMD is greatly needed. This paper presents a comprehensive numerical PMMP flow model. By solving discrete particle force balance equations coupled with continuity equations and momentum equations for carrier gas, the dynamic behavior of PMMP flow through powder feeder pipe and out of nozzle was calculated. To verify modeling results, pre-mixed Cu and 4047 Al powder was transported and patterned in an epoxy resin coating after exiting nozzle. The distribution of exiting pre-mixed powder was plotted by quantifying the volume percentages of different powders. The gathered distribution data was used to estimate the exiting pre-mixed powder’s composition, and finally validate modeling results.