Tribological Investigations on Additively Manufactured Inconel 718 Features with Silicon Carbide Ball: Role of the Tribo-Oxide Layer

The current investigation delved into the friction and wear characteristics of abrasive-finished Inconel 718 alloys fabricated by additive manufacturing and casting methods. Silicon carbide balls were used as counter-body materials for all tribology tests. Variable loads of 10 N, 20 N, and 30 N were applied, along with frequencies of 5 Hz and 15 Hz, while maintaining a 1 mm stroke length for 30 min. Cast samples showed an increase in coefficient of friction (COF) when the load increased from 10 to 20 N at 5 Hz. COF value was decreased from 0.28 to 0.25 when the load was increased from 20 to 30 N while the frequency was maintained at 5 Hz. At the same frequency of 5 Hz, additively manufactured samples displayed a constant increase in COF from 0.19 to 0.35 as the load increased from 10 to 30 N. Consistent COF values were determined at 15 Hz for cast and additively manufactured samples. The COF for cast samples at a frequency of 15 Hz was 0.26, 0.25, and 0.25 for loads of 10 N, 20 N, and 30 N, respectively. For the same loads and frequencies, COF values of 0.23, 0.24, and 0.24 were reported in additively manufactured samples. At 15 Hz, both cast (7.25 x 10-6 mm3/N.m to 9.91 x 10-6 mm3/N.m) and additively manufactured (5.80 x 10-6 mm3/N.m to 6.18 x 10-6 mm3/N.m) samples exhibited constant increasing trends of specific wear rates when the loads increased from 10 to 30 N.