Effect of Environmental Factors on Stainless Steel 316L Powders Used for Laser Powder-Bed Fusion Additive Manufacturing

Additive manufacturing (AM) processes, such as laser powder-bed fusion (LPBF), are commonly used to produce various components by using a laser to melt metal powders. Due to its widespread utilization, stainless steel 316L is one of the most commonly used materials in LPBF. It is well known that powders used in LPBF are affected by various factors, such as the manufacturing process, composition, and size. It is widely believed that variations in powder properties, such as powder size, composition, etc., can affect the printed parts. Results from literature highlight the impact of powder properties on the porosity, mechanical properties, and surface characteristics of printed LPBF parts. In this work, the effects of environmental factors, such as humidity, on the properties of powders will be studied. The study will look into the flowability, microstructure, and powder size of as-received powders. Next as-received powders will be subjected to humid environments and tested for various powder properties. Results will be compared to assess the impact of humid and as-received powders. It is believed that increase in powder humidity would decrease the flowability of metal powders used for LPBF and therefore would affect printed parts. This will allow us to gain a deeper understanding of the effect of humid powder on powder properties.