摘要:
A method of forming a wear-resistant coating on a substrate surface includes the step of cold gas-dynamic spraying a material comprising a rhenium-based composition onto the substrate surface. A metal layer may be formed on the substrate surface prior to the cold gas-dynamic spraying step, and a heat treatment may be performed after the gold gas-dynamic spraying step.
摘要:
Pressure powder metallurgy process for consolidating refractory or rhenium alloys using a reduced temperature and elevated pressure. Rhenium metal has high temperature strength and wear resistance but has a very high melting point as a pure metal and thus is difficult to use as a coating for many alloys having lower melting points. The reduced temperature and elevated pressure alloying process of the rhenium allows it to be used as a coating for other metal alloys, such as nickel and steel alloys, providing some high temperature and wear resistance due to the properties of the rhenium material in the coating.
摘要:
A solid free form fabrication method is performed for manufacturing a component from successive layers of metal feedstock material, with each of the successive layers representing a cross-sectional component slice. First, a first of the successive layers is formed by directing the feedstock material to a predetermined region, the layer comprising at least one crystal grain. Then, the at least one crystal grain is deformed to create dislocations therein. A second layer is formed on the first layer, and the first and second layers are heated to form new crystal grains that are differently sized than the at least one crystal grain.
摘要:
An ion fusion formation method is used to manufacture a component from successive layers of feedstock material. A plasma stream is created by energizing a flowing gas using an arc electrode, the arc electrode having a variable magnitude current supplied thereto. The plasma stream is directed to a predetermined targeted region, and the feedstock material is introduced into the plasma stream to produce a pool of molten feedstock in the predetermined targeted region, the molten feedstock being produced at a temperature determined in part by parameters of the variable magnitude current. Prior to introducing the feedstock material into the plasma stream, optimal molten feedstock parameters may be determined for producing the layers of feedstock material. Feeding parameters by which the feedstock material will be introduced into the plasma stream are then adjusted in view of the determined optimal molten feedstock parameters.
摘要:
A solid free form fabrication system for manufacturing a component by successively building feedstock layers representing successive cross-sectional component slices includes a platform for receiving and supporting the feedstock layers, a feedstock supplying apparatus that deposits the feedstock into a predetermined region to form the feedstock layers, an energy source directed toward the predetermined region to modify the feedstock in the predetermined region and thereby manufacture the component, and a temperature control block disposed on the platform and directly in contact with the deposited feedstock layers to modify the feedstock temperature while manufacturing the component. A solid free form fabrication method uses the system to manufacture the component from the feedstock material
摘要:
An ion fusion formation (IFF) system uses a plasma welding torch to create ions that heat feedstock for application at a deposition point. A plasma welding torch may use argon gas or the like in order to provide extremely hot ions that impact or collide with the feedstock in order to melt it and enabling application of the melted feedstock to a deposition point on a workpiece. By positioning the workpiece, wire feeder, and/or welding torch, parts, devices, or components can be built in almost any three-dimensional shape. Parts can be manufactured in a “just-in-time fashion” with high precision and predictable performance.
摘要:
The present invention provides methods of manufacturing a hot gas valve for a divert and attitude control system in a propelled craft. The methods include the steps of building a valve, or a plurality of separate valve components or segments using a solid free-form fabrication process, and assembling the plurality of separate valve components or segments if necessary to produce the hot gas valve. The solid free-form fabrication process comprises the steps of forming successive feedstock layers by depositing the feedstock material into a predetermined region, the feedstock layers representing successive cross-sectional component slices, and modifying the feedstock by directing an energy source to the predetermined region and thereby creating modified regions in the successive feedstock layers, the combined modified regions defining the hot gas valve or an at least partially-formed valve component or segment.
摘要:
A hot gas valve disc for a divert and attitude control disc switching element used in a propelled craft. The hot gas valve disc comprises a first layer comprising a first metal material having a first grain size and a first grain orientation, and at least one additional layer comprising a second metal material having a second grain size that differs from the first grain size, or a second grain orientation that differs from the first grain orientation. A method of manufacturing the hot gas valve disc comprises the steps of fabricating a first metal layer using a solid-free-form fabrication process, the first metal layer having a set of grain characteristics comprising grain size and grain structure, followed by heating the first layer and thereby changing at least one of the grain characteristics.
摘要:
A refractory alloy that includes rhenium as the most abundant alloy component by atomic percent includes tungsten, and at least one element having a higher oxygen affinity than rhenium and having a melting temperature of at least 1650° C. One exemplary alloy includes at least 90% rhenium by atomic percent, about 0.25% to about 4% tungsten by atomic percent, and about 0.25% to about 2% tantalum by atomic percent.
摘要:
A bearing for a high-speed and high-momentum rotating flywheel system for satellite or other applications that enables better recovery when unintended physical contact occurs. This better recovery is achieved through increased impact resistance and wear resistance by using a flat annulus connected to the main shaft of the primary bearing and secondary metal bearing and coating both annuli with rhenium or its alloys. Rhenium has a very high melting point but in the annealed condition is ductile so the rhenium coating is hardened to a very high strength and wear resistance but the rhenium beneath is still ductile. This combination of hard and soft material provides good wear resistance and impact resistance for those times when the primary bearing ceases to operate and contact is made with the secondary bearing.