Experimental Tribological Study on Additive Manufactured Inconel 718 Features Against the Hard Carbide Counter Bodies

Abstract

In past years, machining processes have been required when fabricating the complex Inconel 718 parts, and these processes cause undesired tensile residual stresses. Inconel 718 also exhibits extreme work hardening throughout the machining process. To avoid these issues, recently, Inconel 718 parts with high geometric complexity and dimensional accuracy, the laser powder bed fusion (LPBF) process, which belongs to additive manufacturing, has been extensively used. These Inconel 718 parts with LPBF processing are frequently utilized in various industries, including aerospace, automotive, pharmaceutical, and food processing, because of their high strength, biocompatibility, and corrosion resistance. Wear resistance is essential in addition to these properties for designing and crushing applications. In this paper, tribological tests were conducted on the LPBF-processed Inconel 718 parts and compared to casted Inconel 718 parts against the four types of counter bodies, namely boron carbide, silicon carbide, tungsten carbide, and titanium carbide. The studies were carried out for 30 min with a constant load of 5 N, frequency of 10 Hz, and stroke length of 1 mm. In comparison to casted samples, LPBF-processed samples showed low coefficient of friction (COF) values. The highest COF was observed on the cast Inconel 718 against the tungsten carbide counter body. The wear mechanisms were studied using scanning electron microscopy.