摘要:
A WC—Co material or polycrystalline diamond-Co material that has a gradient in the grain size of the particles. Specifically, the material may have a top layer that has coarse grains that is designed to dissipate the heat caused by friction (and thus prevent thermal cracking). The material will then have a bulk substrate that is made up of finer grains and provide adequate hardness for the material. The top layer is positioned on top of the bulk substrate.
摘要:
The present disclosure provides compositions and methods directed to polycrystalline diamond materials. In one embodiment, a polycrystalline diamond material can comprise sintered polycrystalline diamond and a binder alloy, where the binder alloy is a liquid at a sintering temperature of the polycrystalline diamond, forms an intermetallic compound at a low temperature below the sintering temperature, and is substantially all intermetallic phase.
摘要:
A method for manufacturing functionally graded cemented tungsten carbide with hard and wear-resistant surface and tough core is described. The said functionally graded cemented tungsten carbide (WC—Co) has a surface layer having a reduced amount of cobalt. Such a hard surface and tough core structure is an example of functionally graded materials in which mechanical properties are optimized by the unique combination of wear-resistance and toughness. WC—Co with reduced-cobalt surface layer may be fabricated through a carburization heat treatment process following conventional liquid phase sintering. The graded WC—Co thus obtained contains no brittle η phase.
摘要:
Processes for coating metal surfaces are disclosed and described. Applying a metal powder (24) to a metal substrate (12) under plasma transferred arc conditions can promote in-situ reaction between these materials. A substantially nonporous intermetallic alloy coating (28) can be formed in this manner and is particularly suited to Fe, Ni, and Co based intermetallic alloys.
摘要:
A method for manufacturing functionally graded cemented tungsten carbide with hard and wear-resistant surface and tough core is described. The said functionally graded cemented tungsten carbide (WC—Co) has a surface layer having a reduced amount of cobalt. Such a hard surface and tough core structure is an example of functionally graded materials in which mechanical properties are optimized by the unique combination of wear-resistance and toughness. WC—Co with reduced-cobalt surface layer may be fabricated through a carburization heat treatment process following conventional liquid phase sintering. The graded WC—Co thus obtained contains no brittle η phase.
摘要:
A process includes roasting a TiO2-containing material in the presence of an alkaline material to form a roasted product; leaching the roasted product with an acidic solution to form a leach liquor; extracting the leach liquor with an extractant to form a raffinate including a Ti4+ species; hydrolyzing the Ti4+ species to form a hydrolyzed material that includes H2TiO3; calcining the hydrolyzed material; and recovering a TiO2 product.
摘要:
This chemical vapor synthesis process was designed so that a metal carbide precursor and a secondary metal precursor are separately or together fed into each evaporator in a reactor by specially designed precursor feeders, either simultaneously or sequentially. The reduction and carburization of the vaporized precursors by gaseous mixtures produces carbide-metal nanocomposite powders. The product can be a very uniform mixture of the constituent powders or a uniform agglomerate, which is important to ensure a high quality of bulk cemented metal carbide product after consolidation and sintering. These nanocomposite powders can be readily characterized using XRD, carbon analyzer and TEM.
摘要:
As a promising clean fuel for vehicles, hydrogen can be used for propulsion, either directly or in fuel cells. Hydrogen storage compositions having high storage capacity, good dehydrogenation kinetics, and hydrogen release and uptake reactions which are reversible are disclosed and described. Generally a hydrogen storage composition of a metal aluminum hexahydride and a metal amide can be used. A combined system (Li3AlH6/3LiNH2) with a very high inherent hydrogen capacity (7.3 wt %) can be carried out at moderate temperatures, and with approximately 95% of that inherent hydrogen storage capacity (7.0%) is reversible over repeated cycling of release and uptake.
摘要:
The invention provides methods, compositions, and systems for a reversible hydrogen storage material. The hydrogen storage material contains a lithium-magnesium compound, having LiMgN in a dehydrogenated state and a hydrogenated lithium magnesium product in a hydrogenated state, where the hydrogenated and dehydrogenated states are reversible. The lithium-magnesium compound is formed by reacting MgH2 and LiNH2 in a substantially inert atmosphere in amounts sufficient to obtain a hydrogen adsorption of at least 3 wt %, and in many cases up to about 8.1 wt %.
摘要翻译:本发明提供了用于可逆储氢材料的方法,组合物和系统。 储氢材料含有脱氢状态的LiMgN和处于氢化状态的氢化锂镁产物的氢化和脱氢状态是可逆的锂 - 镁化合物。 在基本上惰性的气氛中使MgH 2 O 2和LiNH 2 H 2反应,其量足以获得至少3重量%的氢吸附量,而在 许多情况下高达约8.1wt%。
摘要:
The present invention is a method for producing functionally graded materials that contain a hard phase that is embedded in a metal matrix phase. The material have a continuous gradient of a matrix metal phase. An example of these types of materials include functionally graded cemented tungsten carbide (the hard phase) that has a continuous gradient of cobalt (the matrix metal) from one reference position, for example, one surface of a part, to another reference position, for example, the opposite surface of the part or within the part. The functionally graded materials are sintered via a liquid phase sintering (LPS) technique. In order to achieve the desired continuous gradient of the matrix metal, an initial gradient of one of the chemical elements of the hard phase is designed and built into the part prior to liquid phase sintering. The exact gradient of the composition material elements that will be required depends on factors such as the desired final matrix metal gradient, the dimension of the part to be made, and the sintering time and temperature.