Method and apparatus for forming coatings of finegrated and/or equiaxed grain structure and articles resulting therefrom.

摘要

Fine-grained and/or equiaxed tungsten and/or rhenium coatings, substantially free from columnar structure, are deposited on substrates (especially graphite) by chemical vapor deposition by directing the flow of reactant gases to the substrate with high velocity and in close proximity thereto, most often at a velocity gradient of at least about 1050 and preferably at least about 2000 cm./cm.-sec. The deposition process is preferably conducted while moving the substrate so as to coat large areas thereof. By this method, tungsten and/or rhenium-coated articles useful as X-ray targets having excellent properties under conditions of rapid temperature cycling may be produced.