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The Al 2 O 3 -TiO 2 coating for turbine blades is being used since long. During the last decades, a large number of papers have been published, but work on property assessment of Al 2 O 3 -TiO 2 coating on rotating component from tribological point of view is very less. This paper assesses the wear behaviour of Al 2 O 3 -TiO 2 coating on inconel 601. The Al 2 O 3 -TiO 2 coating on inconel 601 is deposited by plasma spray process. The SEM results show that above 300 o C, the friction coefficient decreases due to softening of coating material. The wear rate increases with increase in temperature. The coating showed brittle fracture at higher temperature. Other test results have shown the drastic changes in property due to load and temperature.

The magnesium alloys occupy an important place in marine applications, but their poor corrosion resistance, wear resistance, hardness and so on, have limited their application. To meet these defects, some techniques are developed. Microarc oxidation is a one such recently developed surface treatment technology under anodic oxidation in which ceramic coating is directly formed on the surface of magnesium alloy, by which its surface property is greatly improved. In this paper, a dense ceramic oxide coating, ~20 μm thick, was prepared on an Y1 magnesium alloy through microarc oxidation in a Na 3 SiO 3 -Na 2 WO 4 -KOH-Na 2 EDTA electrolytic solution. The property of corrosion resistance of ceramic coating was studied by CS300P electrochemistry-corrosion workstation, and the main impact factor of the corrosion resistance was also analysed. Microstructure and phase composition were analysed by SEM and XRD. The microhardness of the coating was also measured. The basic mechanism of microarc coating formation is explained in brief.The results show that the corrosion resistance property of microarc oxidation coating on the Y1 magnesium surface is superior to the original samples in the 3⋅5 wt% NaCl solutions. The microarc oxidation coating is relatively dense and uniform, mainly composed of MgO, MgAl 2 O 4 and MgSiO 3 . The microhardness of the Y1 magnesium alloy surface attained 410 HV, which was much larger than that of the original Y1 magnesium alloy without microarc oxidation.

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Since hydroxyapatite has excellent biocompatibility and bone bonding ability, porous hydroxyapatite ceramics have been intensively studied. However, porous hydroxyapatite bodies are mechanically weak and brittle, which makes shaping and implantation difficult. One way to solve this problem is to introduce a strong porous network onto which hydroxyapatite coating is applied. In this study, porous zirconia and aluminaadded zirconia ceramics were prepared by ceramic slurry infiltration of expanded polystyrene bead compacts, followed by firing at 1500°C. Then slurry of hydroxyapatite-borosilicate glass mixed powder was used to coat the porous ceramics, followed by firing at 1200°C. The porous structures without the coating had high porosities of 51-69%, high pore interconnectivity, and sufficiently large pore window sizes (300-500 μm). The porous ceramics had compressive strengths of 5⋅3∼36⋅8 MPa, favourably comparable to the mechanical properties of cancellous bones. In addition, porous hydroxyapatite surface was formed on the top of the composite coating, whereas a borosilicate glass layer was found on the interface. Thus, porous zirconia-based ceramics were modified with a bioactive composite coating for biomedical applications.