METHOD FOR MANUFACTURING CERAMIC THERMAL BARRIER COATINGS HAVING EXCELLENT ADHESION AND THERMAL DURABILITY

摘要

The present invention relates to a manufacturing method for a ceramic thermal shield coating layer having an excellent adhesion force and thermal durability, comprising: (a) a step of respectively preparing a first suspension, on which first oxide particles for thermal shield coating are dispersed, and a second suspension, on which second oxide particles for thermal shield coating are dispersed; (b) a step of using the first suspension to form a first coating layer on a basic material by suspension plasma spraying (SPS); (c) a step of using a mixed suspension of the first suspension and the second suspension to form a buffering layer on the first coating layer by SPS; and (d) a step of using the second suspension to form a second coating layer on the buffering layer by SPS. According to the present invention, the manufacturing method for the ceramic thermal shield coating layer is able to use two types of suspension, which include YSZ, including an oxide particle crushed by a high-energy milling or a complex oxide particle, which is made into an alloy, and rare-earth zirconate, to form a double-layered ceramic thermal shield coating layer by the SPS with a connected suspension supplier, to deposit rare-earth zirconate which has a pyrochlore or a fluorite phase with a low thermal conductivity and an excellent high-temperature phase stability, on an upper layer, which is a high-temperature layer, on the relevant coating layer, and to deposit YSZ which has a thermal expansion coefficient, which is very similar to that of a substrate, and superior high-temperature mechanical characteristics, on a lower layer, which is a low-temperature layer, thereby forming the double-layered ceramic thermal shield coating layer which is available at a little higher temperature than that of the conventional YSX single-layered coating, and has an adhesion force and a high-temperature durability at 1,200 °C or higher, which are the same as or improved from those of the conventional YSZ single-layered coating.