Experimental Investigation: Controlling/Predicting Deposit Microstructure and Mechanical Performance in 316L Stainless Steel Produced via OneClick Metals Laser Powder Bed Fusion Printer

Metal additive manufacturing (AM) offers an exciting new tool for rapidly producing near net shape components with minimal post processing. Understanding and predicting the mechanical performance of AM metal components is important for reliable utilization. However, due to the relatively short time that metal AM has been around, the process, microstructure, and property relationships are poorly understood. An experimental design was conducted to reveal the effects of laser scanning velocity and laser power at ranges of 1280mm/s to 128mm/s and 200W to 80W, respectively. The parameters were paired and adjusted in a way to keep the energy density at 7 linear power densities ranging from 625 W/m to 156.25 W/m. Three replicates of 49 paired parameters were printed and analyzed to establish the microstructural evolution related to the changes in the printing parameters. Quantitative metallography was conducted using a Keyence VHX-X1 750 and revealed variations in porosity percent, density and shape of discontinuity, microstructure, and grainsize. Hardness measurements provide insight into the effect of the microstructural differences on the mechanical performance. Results discussing how printing parameters can predict/control component porosity, microstructure, and mechanical strength will be presented.