摘要 |
A new composition and methods for densifying a refractory oxide coating. The new composition includes two substituents. The first substituent is the reaction mixture produced by combining 80% formic acid and saturated aqueous chromic acid. The second substituent includes either phosphoric acid or monoaluminum phosphate. The proportions of the first substituent:second substituent vary from about 5:9 (weight:weight) to about 3:2 (weight:weight). A refractory oxide coating may be densified by first applying the new composition to the refractory oxide coating, then heating to a temperature of at least about 450 DEG F., followed by cooling. A refractory oxide coating may be further densified by repeating this process one or more additional times. Alternatively, the first and second substituents may be sequentially applied to the refractory oxide coating before heating and cooling operations.
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