The Effect of Modulation Ratio of Cu/Ni Multilayer Films on the Fretting Damage Behaviour of Ti-811 Titanium Alloy

Abstract

To improve the fretting damage (fretting wear and fretting fatigue) resistance of Ti-811 titanium alloy, three Cu/Ni multilayer films with the same modulation period thickness (200 nm) and different modulation ratios (3:1, 1:1, 1:3) were deposited on the surface of the alloy via ion-assisted magnetron sputtering deposition (IAD). The bonding strength, micro-hardness, and toughness of the films were evaluated, and the effect of the modulation ratio on the room-temperature fretting wear (FW) and fretting fatigue (FF) resistance of the alloy was determined. The results indicated that the IAD technique can be successfully used to prepare Cu/Ni multilayer films, with high bonding strength, low-friction, and good toughness, which yield improved room-temperature FF and FW resistance of the alloy. For the same modulation period (200 nm), the micro-hardness, friction, and FW resistance of the coated alloy increased, decreased, and improved, respectively, with increasing modulation ratio of the Ni-to-Cu layer thickness. However, the FF resistance of the coated alloy increased non-monotonically with the increasing modulation ratio. Among the three Cu/Ni multilayer films, those with a modulation ratio of 1:1 can confer the highest FF resistance to the Ti-811 alloy, owing mainly to their unique combination of good toughness, high strength, and low-friction.

A Review of Research Progress on the Fretting Fatigue Mechanism and Protection Measures of Metal Matrix Composites

“…Therefore, considerable work has been conducted to investigate the use of surface modification techniques in improving the resistance of materials to fretting fatigue, mainly by reducing the COF or increasing the hardness and yield strength of the fretting contact surface to improve the material's resistance to fretting fatigue damage performance. Commonly used methods [114][115][116][117] are surface mechanical strengthening, surface heat treatment, chemical heat treatment, electrochemical treatment, thermal spray technology, dry film lubrication layer, ion coating and ion implantation technology, chemical vapor deposition, and physical vapor deposition.…”

Influence of soft interlayers on fretting fatigue and fretting wear resistance of Ti-6Al-4V alloy

“…The Cu/Ni film could significantly improve the fretting wear and fretting fatigue resistance of Ti-811 at room temperature because its excellent comprehensive properties with well toughness, high strength and good lubrication action. The studies of Zhang [7,8], Jin [9] and Du [2] indicated that the lubrication coating were beneficial to improving the wear resistance of materials by reducing its friction coefficient. Thus, the soft foils of copper, nickel and PTFE with well lubrication were helpfully to reduce the friction coefficient of fretting wear on titanium alloy surface.…”