| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacture of a tool material for burning, having a dense sprayed coating minimal in peeling and excellent in durability. SOLUTION: A raw material, composed essentially of α-Al2 O3 , is thermally sprayed onto a part or the whole surface of an aluminous base material, by which an Al2 O3 thermally sprayed layer, having a chemical composition containing >=98wt.% Al2 O3 and also having a mineral composition in which, by powder X-ray analysis, the proportion of the sum of the X-ray intensities in (312) plane of δ-Al2 O3 and (220) plane of γ-Al2 O3 to the sum of the X-ray intensities in (312) plane of δ-Al2 O3 , (220) plane of γ-Al2 O3 , and (024) plane of α-Al2 O3 is regulated to 20-50%, is formed. By applying heat treatment at 1200-1700 deg.C to the above layer, this layer is modified into a thermally sprayed layer composed essentially of α-Al2 O3 , in which the proportion of the sum of the X-ray intensities in (312) plane of δ-Al2 O3 and (220) plane of γ-Al2 O3 to the sum of the X-ray intensities in (312) plane of δ-Al2 O3 , (220) plane of γ-Al2 O3 , and (024) plane of α-Al2 O3 , in powder X-ray analysis, is regulated to <=5%. |
