الفهرس 
Introduction
Surface engineeringOnly 14 pages are availabe for public view
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Abstract
Thermal barrier coatings (TBC?s) is one of the used surface modification techniques to increase the surface stability of alloys during service without loosing the mechnical properties of the bulk material. Thermal barrier coatings (TBC?s) consists of metallic part which is oxidation resistance alloy and ceramic part. Plasma spraying is a technique used to over lay the TBC?s on the surface of high temperature alloys.Thermal barrier coatings (TBC?s) can be used as duplex or graded. In order to meet the required properties for operation and efficiency objectives, it is important to characterize the formed TBC?s before application.In the present study of TBC?s, three substrates were examined: Nibase alloys, namely, hastelloy x, Inconel 716 and IN 738. The powder used as bond coat in this study is NiCoCrAlY, CoCrAlY or IN 738 and ceramic coat is partially stabilized zirconia.The oxidation and hot corrosion resistance of these systems are investigated. The TBC?s stability was examined using SEM and EDX. The results showed that the failure mechanism of TBC?s in hot corrosion experiments was the degradation of the ceramic coat due to the precipitation of melted salts in pores, in addition to the formation of thermally growing oxide as hard phase, which accelerates failure.