Microstructures, mechanical properties, and grease-lubricated sliding wear behavior of Cu-15Ni-8Sn-0.8Nb alloy with high strength and toughness

Abstract

Alloys used as bearings in aircraft landing gear are required to reduce friction and wear as well as improve the load-carrying capability due to the increased aircraft weights. Cu-15Ni-8Sn-0.8Nb alloy is well known for possessing good mechanical and wear properties that satisfy such requirements. In this study, the microstructure, mechanical properties, and grease-lubricated sliding wear behavior of Cu-15Ni-8Sn-0.8Nb alloy with 0.8 wt% Nb are investigated. The nanoscale NbNi3 and NbNi2Sn compounds can strengthen the alloy through the Orowan strengthening mechanism. A Stribeck-like curve is plotted to illustrate the relationship among friction coefficient, normal load, and sliding velocity and to analyze the grease-lubricated mechanism. The wear rate increases with normal load and decreases with sliding velocity, except at 2.58 m/s. A wear mechanism map has been developed to exhibit the dominant wear mechanisms under various friction conditions. When the normal load is 700 N and the sliding velocity is 2.58 m/s, a chemical reaction between the lubricating grease and friction pairs occurs, resulting in the failure of lubricating grease and an increase in wear.

Investigation of second phase concentration effects on tribological and electrical properties of Cu–WS2 composites

“…4. Typical copper peaks can be noticed at about 43° for Cu (1 1 1), at about 51° for Cu (2 0 0) and at about 74° for Cu (2 2 0) [18,20,[36][37][38][39]. Tungsten disulfide peaks are detected at about 14° for WS2 (0 0 2), near to 29° for WS2 (0 0 4), at 44° for WS2 (0 0 6) and at about 59° for WS2 (0 0 8) [10,18,20,40,41].…”

Comprehensive characterisation of tribo-layer in a Cu-15Ni-8Sn alloy during dry sliding wear

“…The heavy oxide layers in MML show a higher oxidation level than in OL. (4) The PDL shows a T-M lamellar structure with a high density of dislocations located inside. The lamellar structures are refined and then the elongated nanocrystallines are formed with continuing plastic deformation during the dry wear test, owing to the driven by minimising the total free energy of a high density of dislocations.…”

“…Age-hardening Cu-15Ni-8Sn alloy, a spinodal hardening alloy, is one of the most promising substitutes for Cu-Be alloys, showing exceptional bearing properties under both dry and lubricated sliding [1-5]. Thus the Cu-15Ni-8Sn alloys can stably operate under severe load in bearing or bushing systems, such as bearings or bushing for large jet aircraft, off-road systems, and heavy-duty mechanical systems [6-8].…”