| 摘要 |
<p>The coating material consists of a finely divided filler (F) with low coefficient of expansion, diserpsed in a binder (b) consisting of metal hdyroxide, chromic acid and magnesium hydrogen phosphate dissolved in orthophosphoric acid. (F) pref. constitutes 30-70% of the total. (F) is pref. quartz flour or similar heat resistant pigments (B) is pref. 20-30% of metal hydroxide (chromic, aluminium or nickel) dissolved in 10-15% orthophosphoric acid, with addition of 10-15% chromic acid and about 1% magnesium hydrogen phosphate. The material is applied in liquid form to mould surfaces and heated stepwise to 300 degrees C. It has good corrosion and heat resistance and adheres well to metal and ceramic surfaces. It is suitable for coating moulds for casting lead and its alloys, and lasts almost indefinitely.</p> |
