Method for forming non-columnar deposits by chemical vapor deposition

摘要

Fine-grained and/or equiaxed coatings, substantially free from columnar structure, are deposited on substrates 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 X-ray targets having excellent properties under conditions of rapid temperature cycling may be produced.