VAPOR DEPOSITION OF TUNGSTEN AND THE EFFECTS OF PROCESS VARIABLES
Abstract
Activities were to include research into the vapor deposition of tungsten on Polaris nozzle components and variables of W vapor deposition. A 0.06-in. coating of high-purity W was to be vapor deposited from tungsten hexafluoride ontoA TUNGSTEN-BERYLLIA MERM nozzle insert and 4 standard graphite test nozzle inserts. Cylinders deposited at different temperatures under atmospheric pressure and constant ratio and flow rate of reactant gases showed: (1) metallic impurities in the deposited metal bet een 16 and 56 ppm, the ajor impurity being 4 to 19 ppm of Si; and (2) columnar microstructures for the deposits, increased grain size, and a decrease in Knoop microhardness values from 475 to 600 C and then a constant value throug 700 C. Other experimentation included investigations into (1) changes in physical properties of deposits produced by reactant-gas mixtures having different ratios of H and tungsten hexafluoride, (2) changes in physical properties of W vapor deposited with reaction chamber pressures equivalent to 3 to 7 in. of H2O, (3) the preferential removal of impurities present in commercially prepared tungsten hexafluoride, and (4) the bonding characteristics of W vapor deposited on various substrate materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1962
- Accession Number
- AD0278010
Entities
People
- F.w. Hoertel