Experimental Investigation on Wear Behavior of Additively Manufactured Components of IN718 by DMLS Process

Abstract

Direct metal laser sintering (DMLS) is a promising technology having applications in diverse areas like aerospace, automotive and energy. This technique is capable of fabricating complex components from hard to machine materials like Inconel and titanium alloys with relative ease. Inconel 718 is a widely preferred material for high-end applications involving challenging environments such as elevated temperatures and pressures, wherein the wear behavior of the material is of utmost significance. So this study aimed to investigate the wear behavior of DMLS IN718 specimens and compare it with that of conventionally cast specimens manufactured by vacuum induction melting (VIM) process. The testing of the specimens was done using a pin-on-disk wear tester against two different disks; IN718 is made by VIM casting process and wrought En-31 under varying normal load and sliding velocity. Also, the DMLS IN718 specimens were built in two orientations, i.e., horizontal and angular. It was observed that the wear rate increased with an increase in load and sliding velocity. The coefficient of friction showed a decreasing trend while sliding against IN718 but exhibited a random behavior with En-31. The wear behavior of the DMLS and conventionally cast-made IN718 specimens was found to be in a similar range, and the built orientation in DMLS did not significantly impact the wear behavior. The subsequent scanning electron microscope images of the wear tracks revealed that the mechanism of wear was a combination of adhesive wear and delamination wear resulting from abrasive action.