| 摘要 |
<p>The protective coating is applied by generation of a gas inert to the stores being treated. The gas contains a substituted hydroxy-containing aluminium compound capable of being vaporised. The gas contacts the surfaces of the stores at 250 degrees - 1000 degrees C to form a coating of 0.1 to 10.0 microns thick. The coated store is then heated at 800 to 1400 degrees C for 30 to 200 min. and finally cooled to room temp. Pref. the gemstone is topaz, rutile or strontium titanate and the aluminium cpd. is an aluminium alcoholate esp. isopropylate.</p> |
