Y.H. Lu

Fretting Wear Behavior and Mechanism of Inconel 690 Alloy Related to the Displacement Amplitude

ABSTRACT Fretting wear tests on Inconel 690 alloy were carried out at different displacement amplitudes. The results indicated that with an increase in displacement amplitude, the ratio of tangential force to normal load and wear volume increased. The fretting mode gradually transformed from mostly stick, mixed stick–slip, to full sliding, showing the competition of fretting-induced fatigue cracking and fretting-induced wear. There was a gradient plastic strain created by fretting, which resulted in the formation of a nanocrystalline tribologically transformed structure (TTS) and plastic deformation layers. The plastic strain in the plastic deformation layer gradually increased with an increase in displacement amplitude.

Effect of Cold Rolling on the Fretting Wear Behavior and Mechanism in Inconel 600 Alloy

ABSTRACT The fretting test was carried out using an SRV IV fretting test rig in order to investigate the fretting wear behavior and mechanism in Inconel 600 alloy at room temperature. The materials were rolled to different reductions before the test. The effect of cold rolling on the friction coefficient and wear volume was subsequently investigated. The surface and cross-sectional morphologies of the wear scar were studied by scanning electron microscopy (SEM), laser scanning confocal microscopy (LSCM), and electron back-scattering diffraction (EBSD). The results indicated that the cold rolling had a different effect on wear behavior in different slip regimes. In the stick regime, cold rolling strongly decreased the wear volume, although it did not affect the friction coefficient. The 25% rolled specimen had the minimum wear volume. The mechanisms of as-received and 50% rolled specimens were delamination and oxidation wear, whereas for the 25% rolled specimen, cracking was the main wear mechanism. In the gross slip regime, cold rolling had little effect on the friction coefficient or wear volume. The fretting wear process gave rise to a decrease in the Σ3 grain boundary, an increase in local misorientation, and a change in the crystal orientation.