High temperature tribological behaviour of Al/Al₂O₃ composite coating on γ-TiAl

Abstract

To improve the high temperature wear resistance of Ti-46?5Al-1Cr-1?5V, an Al/Al 2 O 3 composite ceramic coating was prepared on it by radio frequency sputtering. In this paper, microstructure, elements distribution, phase identification of the Al/Al 2 O 3 composite coating were investigated. Also, its nanohardness and elastic modulus were examined. High temperature dry sliding wear behaviour at 300uC was analysed in details. The results indicated that the homogeneous and dense composite coating was about 20 mm thick. Additionally, the composite coating possessed higher H/E and H 3 /E 2 ratios than those of substrate. Compared to the substrate, the Al/Al 2 O 3 composite coating recorded a lower friction coefficient and the volume loss of Al/Al 2 O 3 coating was only 1/3 of the bare substrate under dry sliding conditions at 300uC. All the results demonstrated that the Al/Al 2 O 3 coating has effectively improved the wear resistance of Ti-46?5Al-1Cr-1?5V at 300uC.

Linear reciprocating wear behaviour of plasma-sprayed Al2O3–Cr2O3 coatings at different loading and sliding conditions

“…Similar studies are performed by Manojkumar et al [9] on wear rate analysis of plasma-sprayed Al 2 O 3 -ZrO 2 composite coating. A number of research groups have explored the tribological properties of thermally sprayed coatings under varying test parameters, such as load and sliding velocity [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], sliding distance [22,27], time of sliding [28], number of cycles [12,29], frequency, reciprocating amplitude [26] and high temperature [20,23,29] conditions. However, few reports are available on the compound effects of the variations in loading and sliding conditions on the tribological performance of the coating.…”