Tungsten Thin Films and Nanometer Powders by Low Pressure Plasma Spray

A new plasma chemical process has been found that produces tungsten thin films. Using fine powders or precursors, the plasma chemical process vaporizes and then deposits nanometer size grains. Deposition kinetics of structures built from nanometer grains varies greatly from classical plasma spray. Equiaxed and columnar grains are formed instead of classical splat structure. Thermodynamic analyses confirm vaporization time. 50-150 nanometer size tungsten powders have been produced. The Vicker hardness values by this technique showed an average value of 425.6 HV compared to 386 HV by conventional plasma spraying.