Tribocorrosion performance of additively manufactured CuNi30 and SS-316L in marine environment: Seawater resistant alloys
Muhammad Ammar Anjum, Ananya Nath, Sneha Goel, Ermei Mäkilä, Sagar Sarkar, Antti Salminen, Ashish Ganvir
Abstract
This study presents the first systematic investigation of the tribocorrosion resistance of additively manufactured CuNi30 in artificial seawater (ASTM D1141-98), along with mechanical and tribocorrosion performance comparison against SS-316L. Both alloys were produced by laser powder bed fusion (PBF-LB/M), achieving relative densities of 99.8% (CuNi30) and 99.1% (SS-316L). The as-built CuNi30 exhibited a tensile strength of 503MPa, which increased to 638MPa after heat treatment at 550°C for 2 hours, reaching parity with SS-316L. Phase identification through X-ray diffraction confirmed the precipitation of Nb-rich precipitates (NbNi 3 ) after heat treatment which contributed to the observed strengthening. The tribocorrosion performance was evaluated using a ball-on-disk setup, where potentiostatic, potentiodynamic, EIS, and COF measurements were recorded under both static and sliding conditions to assess corrosion-wear interactions. The results revelated that SS-316L is more susceptible to tribocorrosion damage due to its lower polarization stability and the formation of thin unstable third body layer. The calculated wear rate showed a decrease from 9.07x10 -8 mm 3 /N·mm for SS-316L to 2.08x10 -8 mm 3 N·mm for heat-treated CuNi30, highlighting the superior tribocorrosion resistance of CuNi30.