Abstract: To prepare a thermally sprayed composite material, a precomposited powder is first prepared and then thermally sprayed at an ambient pressure of no less than about 0.75 atmosphere in an oxidation-preventing atmosphere. The precomposited powder has a plurality of powder particles, and each powder particle is formed of a matrix and reinforcing particles distributed within and encapsulated by the matrix. The matrix has a composition of a matrix metal such as molybdenum, hafnium, zirconium titanium, vanadium, niobium, tantalum, or tungsten, and a matrix non-metal of silicon, boron, or carbon. The reinforcement particle is silicon carbide, boron carbide, silicon nitride, or boron nitride.

Abstract: Nanoscale aluminum alloy powder is synthesized by mechanical alloying/milling techniques without significant oxidation, nitridation, or contamination with foreign materials. These powders are consolidated into a very dense billet form without a high temperature sintering step. The desired microstructure and properties were obtained by post hot isostatic pressing, extrusion, and/or forging of the nanoscale material billet made from the powders.

Abstract: A mass of molybdenum disilicide-silicon carbide composite material is prepared by providing a mixture of molybdenum disilicide-silicon carbide precomposited powder, and plasma spraying the precomposited powder onto a substrate using argon-shrouded plasma spray deposition, to form a plasma-sprayed mass. The plasma-sprayed mass may be subsequently heat treated.

Abstract: A rocket engine component is formed as a tungsten-copper composite substrate, and a functionally-gradient material coating overlying and contacting the substrate. The functionally-gradient material coating has a composition that varies nonlinearly through a thickness of the coating so as to minimize thermal stresses through the coating, and such that the functionally-gradient material coating is tungsten adjacent to the substrate and is rhenium remote from the substrate. In a preferred form, the functionally-gradient material coating includes a tungsten sublayer overlying and contacting the substrate, a tungsten-rhenium sublayer overlying and contacting the tungsten sublayer; and a rhenium sublayer overlying and contacting the tungsten-rhenium sublayer. The functionally-gradient material coating is preferably applied by a low-temperature deposition technique such as plasma enhanced chemical vapor deposition.

Abstract: A porous article is densified by creating a plasma adjacent to the surface of the article and introducing a source of a densifying species into the plasma. The article is electrically biased with respect to the plasma to a polarization opposite in sign to the energized densifying species and to a first voltage sufficient to deposit the densifying species to the first depth below the surface of the article. The species is deposited for a time sufficient to densify the article at the first depth. If the article has porosity over a range of depths, as is often the case, the voltage is first set to densify the article at the greatest depth, and thereafter the voltage is gradually decreased to reduce the depth of densification until the article is densified over the entire range.

Abstract: An x-ray tube having a rotating anode structure which comprises a circular titantium, zirconium, molybdenum alloy target section bonded to a graphite disc. The target section is coated with hefnium carbide as a heat emissivity barrier. The thickness of the barrier is preferably in the range of 4.0-5.0 .mu.m.

Abstract: A Belleville spring/ball combination is utilized in a rotating anode target bearing assembly in an X-ray tube for thermal and electrical conduction as well as self-centering of the target shaft and noise reduction.

Abstract: A method of applying solid lubricant to a bearing with rolling surfaces which comprises the steps of sputter cleaning the bearing substrate and implanting ions of the solid lubricant to a shallow depth in the surface of the substrate to improve the bonding of the solid lubricant plating which is subsequently deposited by plasma-assisted ion plating in a thin layer of approximately 1000 .ANG. directly over the implanted substrate and wherein the plating is applied to the bearing substrate at high temperature and in the presence of low pressure inert gas ions to improve surface structure and wherein the bearing element is then cooled in a vacuum.

Abstract: A bearing retainer for mounting for a bearing in an x-ray tube, the x-ray tube having a rotating anode supported on an anode shaft held within a hollow anode stem, the retainer being slidably fitted into a hollow anode stem to hold one bearing coaxially with the anode shaft and to permit axial motion of the bearing so held, where the sliding surface of the bearing retainer is coated with titanium carbide, and wherein the bearing retainer includes a bearing flange not coated with titanium carbide which may be swaged around the outer race of the bearing to hold the bearing.

Abstract: An x-ray tube target has improved heat dissipation by applying a layer of diamond between the focal track and the target body. The diamond layer can be applied directly to a graphite target body, a graphite disc covered with silicon carbide or to a disc composed of an molybdenum alloy such as TZM.

Abstract: A bearing retainer for mounting for a bearing in an X-ray tube, the X-ray tube having a rotating anode supported on an anode shaft held within a hollow anode stem, the retainer being slidably fitted into a hollow anode stem to hold one bearing coaxially with the anode shaft and to permit axial motion of the bearing so held, where the sliding surface of the bearing retainer is coated with a solid lubricant, and wherein the bearing retainer includes a bearing flange not coated with lubricant which may be swaged around the outer race of the bearing to hold the bearing.

Abstract: A method of applying solid lubricant to a bearing with rolling surfaces which comprises the steps of sputter cleaning the bearing substrate and implanting ions of the solid lubricant to a shallow depth in the surface of the substrate to improve the bonding of the solid lubricant plating which is subsequently deposited by plasma-assisted ion plating in a thin layer of approximately 1000 .ANG. directly over the implanted substrate and wherein the plating is applied to the bearing substrate at high temperature and in the presence of low pressure inert gas ions to improve surface structure and wherein the bearing element is then cooled in a vacuum.

Abstract: A bearing retainer for mounting for a bearing in an X-ray tube, the X-ray tube having a rotating anode supported on an anode shaft held within a hollow anode stem, the retainer being slidably fitted into a hollow anode stem to hold one bearing coaxially with the anode shaft and to permit axial motion of the bearing so held, where the sliding surface of the bearing retainer is coated with titanium carbide, and wherein the bearing retainer includes a bearing flange not coated with titanium carbide which may be swaged around the outer race of the bearing to hold the bearing.