Investigation of the Process-Induced Defects in Metal Fused Deposition Modeling Process for Ultrafuse 316L Stainless Steel

Abstract

The current article presents a case study of the defects that can occur in the metal fused deposition modeling (FDM) process, a popular additive manufacturing technique for producing metal parts. The metal parts of Ultrafuse 316L SS filament (a metal-polymer composite) were produced and then subjected to de-binding and sintering. The defects in the brown parts (after de-binding) and the silver parts (after sintering) were analyzed carefully. The main defects detected include brittleness, cracks, blisters, layer delamination, part deformation, and porosity. Further, the formation of these defects was found to be influenced by the process parameters such as heating rate, holding time, temperature, and atmosphere. The analysis of these effects suggests to use furnace temperature of 310 °C, heating rate of 1 °C/min and holding time of around 10 to 15 minutes to minimize the defects. As regard to the atmosphere, vacuum is preferred over other environments to produce parts with reduced defects and enhanced quality.