ENVIRONMENTAL BARRIER COATING FOR HIGH TEMPERATURE CERAMICS COMPONENT

PROBLEM TO BE SOLVED: To provide an environmental barrier coating for a high temperature ceramics component. SOLUTION: The environmental barrier coating is composed of: a bond coat layer 14 made of silicon; an optional silica layer 15; at least one transition layer 16 containing a primary transition material in which about 85 to 100 vol.% of mullite and BSAS are individually or mixedly used and a secondary material selected from rare earth oxides, rare earth bisilicates, rare earth monosilicates, rare earth elements, rare earth-containing aluminosilicate glasses, rare earth-alkaline-earth-containing aluminosilicate glasses, rare earth aluminates, phosphorus pentoxides or the like, and their mixtures of 0 to about 15 vol.%; and an external layer 18 comprising a main outer material made of about 85 to 100 vol.% of BSAS and a secondary material of 0 to about 15 vol.%. The reaction between the a sintering aid in the coating and at least either the main transition material or the main outer material produces the transition layer 16 having a porosity of 0 to about 30 vol.% and the external layer 18 having a porosity of 0 to about 15 vol.%. COPYRIGHT: (C)2011,JPO&INPIT