Verfahren zum Schwaerzen von Oberflaechen

摘要

1307440 SiO 2 coating EUROPEAN ATOMIC ENERGY COMMUNITY (EURATOM) 30 Dec 1970 [30 Dec 1969] 61852/70 Heading C1A A method of blackening surfaces and heatresistant components comprises pyrolysing in a non-oxidizing atmosphere at between 400‹ to 1200‹ C. a surface coating of a hydrolysed silicon compound possessing hydroxy groups. The process should preferably be carried out in a vacuum of at least 10-4 Torr. The minimum period of treatment depends on the temperature, e.g. at 750-850‹ C. 10 minutes suffices. Suitable silicon compounds are polymers formed by the hydrolysis of dimethyl dichlorosilane, methyl trimethoxysilane, methyltrichlorosilane, methyl triethoxysilane, orthosilicic acid esters or polysilicic acid esters. The coating may be applied with a brush, a spatula, by dipping or by spraying. The blackening effect is increased by applying a plurality of layers successively and heat-treating the last applied coating between each two coatings. The substrate may be of niobium or its alloys, molybdenum, tungsten, titanium, stainless steel, beryllium and ceramic materials. The degree of blackening may be enhanced by roughening the surface beforehand, such as by sand-blasting.