Jia-jie Kang

Effect of flame remelting on microstructure and wear behaviour of plasma sprayed NiCrBSi-30%Mo coating

ABSTRACT The effects of flame remelting on the microstructural features, mechanical properties and dry sliding wear properties of supersonic plasma sprayed NiCrBSi-30 wt-% Mo coating were evaluated. The modified microstructure of the flame remelted coating, such as reduction in micro-defects, decrease in line roughness, laminar architecture elimination and material homogenisation was obtained. The Vickers micro-hardness and elastic modulus measurement showed an enhancement for flame remelted coating. The main wear mechanism of the as-sprayed coating was adhesive/delaminative wear. While the main wear mechanism of the flame remelted coating was adhesive wear. The wear resistance of flame remelted coating surpassed that of the as-sprayed coating and was by far superior to the substrate.

Tribological behaviour of textured titanium under abrasive wear

ABSTRACT In order to improve the tribological behaviour of titanium used in aerospace exploration. Dimple textures were prepared on a commercial pure titanium grade 2 (TA2) surface by laser surface texturing. Tribological behaviour of the textured TA2 was investigated under two kinds of simulated lunar soil particles in dry sliding contact. The tribological mechanisms were analysed using NanoMap-D 3D surface profilometer, scanning electron microscope and energy-dispersive spectroscopy. An orthogonal analysis was used to study the influence of dimple parameters on anti-friction and anti-wear performances. The result showed that the textured titanium surface exhibited a better anti-friction and anti-wear performance under the small particle wearing condition compared with that under the large particle. The dimple density had a remarkable effect on both the anti-friction and anti-wear performances under small particle wear, while it became weaker under large particle wear. The dimple depth had almost no effect on the tribological behaviour.