Abstract: A molybdenum-based composite powder for thermal spray applications. The composite powder includes a molybdenum-chromium, molybdenum-tungsten, or molybdenum-tungsten-chromium alloy dispersion strengthened with molybdenum carbide (Mo2C). The molybdenum-based composite powder may be combined with a nickel-based or cobalt-based alloy to form a two-phase powder blend. The coatings from such powders are made up of molybdenum-based alloy lamellae and, in the two-phase embodiments, nickel-based or cobalt-based alloy lamellae. The coatings exhibit improved corrosion resistance and strength while retaining good sprayability.

Abstract: A molybdenum-based composite powder for thermal spray applications. The composite powder includes a molybdenum-chromium, molybdenum-tungsten, or molybdenum-tungsten-chromium alloy dispersion strengthened with molybdenum carbide (Mo.sub.2 C). The molybdenum-based composite powder may be combined with a nickel-based or cobalt-based alloy to form a two-phase powder blend. The coatings from such powders are made up of molybdenum-based alloy lamellae and, in the two-phase embodiments, nickel-based or cobalt-based alloy lamellae. The coatings exhibit improved corrosion resistance and strength while retaining good sprayability.

Abstract: A DC plasma arc generator and method of operation to reduce erosion of the internal parts. The arc generator includes a generally cylindrical anode and a generally cylindrical interelectrode having critical dimensions and spacing to allow introduction of vortical gas flows and stabilization of the primary arc thereby, reducing degradation and erosion of the generator.

Abstract: A DC plasma arc generator and method of operation including a generally cylindrical anode divided into an arc constricting portion and an exit portion lined with refractory liners and having critical dimensions and spacing to allow introduction of vortical gas flows and stabilization of the primary arc thereby, reducing degradation and erosion of the generator.

Abstract: A method is disclosed for preparing an intimate mixture of powders of nickel-chromium-boron-silicon alloy, molybdenum metal powder, and Cr.sub.3 C.sub.2 /NiCr alloy suitable for thermal spray coatings which comprises milling a starting mixture of the above two alloys with molybdenum powder to produce a milled mixture wherein the average particle size is less than about 10 micrometers in diameter, forming an aqueous slurry of the resulting milled mixture and a binder which can be an ammoniacal molybdate compound or polyvinyl alcohol, and agglomerating the milled mixture and binder. The intimate mixture and binder may be sintered in a reducing atmosphere at a temperature of about 800.degree. C. to 950.degree. C. for a sufficient time to form a sintered partially alloyed mixture wherein the bulk density is greater than about 1.2 g/cc.

Abstract: A process for forming particulate tungsten heavy alloys from agglomerated material containing the individual metals by using a high temperature zone is improved by retaining the material in the high temperature zone for a time sufficient to at least partially melt the metals that are alloying with tungsten while maintaining the temperature of those metals below the boiling point of the lowest boiling metal in the alloying component.

Abstract: A process is disclosed for producing fine spherical particles from a fine powder feed material which comprises entraining the powder feed material in a carrier gas, introducing the feed material and carrier gas through a powder port into a high temperature zone and maintaining the powder feed material in the high temperature zone for a sufficient time to melt at least about 50% by weight of the particles of the powder and to form droplets therefrom while at the same time allowing one or more streams of gas to come into contact intermittently with any powder which has accumulated in the vicinity of the powder port to keep the vicinity clear of powder to allow the powder feed to pass unobstructively through the powder port into the high temperature zone. The droplets are then cooled to form spherical particles.

Abstract: A process is disclosed for producing discontinuous metal foils. The process involves entraining metal powder particles in a carrier gas and passing the powder particles through a high temperature zone at a temperature above the melting point of the powder particles to melt at least about 50% by weight of the powder particles and thereafter resolidifying the resulting high temperature treated material by impacting the material against a substrate to form the foils.

Abstract: A process is disclosed for producing metal flakes. The process involves entraining the metal powder particles in a carrier gas and passing the powder particles through a high temperature zone at a temperature above the melting point of the powder particles to melt at least about 50% of the powder particles, resolidifying the resulting high temperature treated material by impacting the material against a substrate, and thereafter contacting the material with a non-oxidizing gas which can be nitrogen, argon, hydrogen, helium or combinations of these to remove the material from the substrate in the form of flakes.