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Showing 1 to 20 of 29 for “"Metal powders"”.
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Sonoelectrochemical synthesis of submicron metal powders
… and demonstrated to produce submicron copper powders. Improvements to the batch reactor design are proposed to extend the technique to a flow reactor useful for commercial production of submicron metal powders.
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Three dimensional printing with fine metal powders
In the area of direct metal part manufacture, the 3DPTM process has several inherent advantages over traditional machining and P/M technologies: hard tooling is not required to manufacture parts, geometries may be created which can not be made by conventional processes, and the composition of parts …
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Combustion dynamics of metal powders in mixed gas flows
… and energetic formulations using micron-sized metal powders, such as aluminum and magnesium. Most current descriptions are based on laboratory experiments performed in stationary or laminar combustion configurations using pure metals burned in single oxidizers. However, practical configurations …
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Cryomilling of Aluminum-based and Magnesium-based Metal Powders
… has been shown to produce nanostructures in metal powders through severe repetitive deformation. Ball milling at cryogenic temperatures (cryomilling) is more effective in this capacity due to the low temperature by slowing recovery and minimizing diffusion distances between different …
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Three dimensional printing by vector printing of fine metal powders
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.
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Combustion signatures of various energetic metal powders in a shock tube experiment
Metal additives are used in explosives and solid propellants in order to increase the energetic output and effectiveness of the explosives or fuel. Aluminum has been the primary solid fuel additive to solid fuel to improve the combustive properties of propellants. Several other metals are being …
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Investigation of residual stresses in the laser melting of metal powders in additive layer manufacturing
… used to produce three-dimensional parts from metal powders by fusing the material in a layerby- layer manner controlled by a CAD model. During LM, rapid temperature cycles and steep temperature gradients occur in the scanned layers. Temperature gradients induce thermal stresses which remain in …
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I. An oxygen-17 NMR study on oxygen exchange in yttrium barium(2) copper(3) oxygen(7-x). II. Synthesis of transition metal polysulfide complexes from metal powders
Covellite, $\rm Cu\sp{I}\sb2(S\sb2)Cu\sp{II}S$ (T$\sb{\rm c}$ = 1.66 K) and $\rm YBa\sb2Cu\sp{II}\sb2Cu\sp{III}O\sb{7-x}\ (T\sb{c}$ = 92 K) are similar in that both are superconductors containing layered structures and mixed valent copper centers. Our studies on YBa$\sb2$Cu$\sb3$O$\sb{\rm 7-x}$ …
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Ignition of metal powder by electrostatic discharge stimulation
Energetic formulations with metal fuel additives are extensively used in propellants, explosives, pyrotechnics, and incendiaries. Currently, replacement of regular metal powders with nanocomposite metal-based materials is being considered. Such nanocomposite reactive materials are capable of very …
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Rehardenable materials system with diffusion barrier for three-dimensional printing
… important applications is the fabrication of metal tooling for plastic injection molding. In order to achieve a fully dense 3DP metal tool, the sintered powder skeleton is infiltrated with a molten alloy, which has a melting point lower than the skeleton material. However, the choices of …
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High green density metal parts by vibrational compaction of dry powder in three dimensional printing process
… material properties and dimensional accuracy of metal tooling produced by the Three Dimensional Printing process can be enhanced by increasing the green density of the 3D printed part. Green density is the ratio of metal powder volume to the external volume of the printed part, and is a measure …
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Constitutive equations for granular materials : application to dry sand and powder metal
… shows a local dip there. Next, we shall focus on metal powders, which are commonly used in powder metallurgy industry to form net- or near-net-shaped components with high relative density by cold compaction. A new constitutive model for cold compaction of metal powders has been developed. The …
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Combustion dynamics of individual reactive material particles
Metallic reactive powders are widely used as solid fuels, pyrotechnic materials, and components of enhanced blast explosives. Metals are attractive because of their high combustion enthalpies and temperatures. Quantitative descriptions of the combustion processes and mechanisms for both pure metal …
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High solid loading aqueous base metal/ceramic feedstock for injection molding
Increasing volume fraction of metal powder in feedstock provided lower shrinkage. Reduction of the shrinkage results in better dimensional precision. The rheology of the feedstock material plays an important role to allowing larger volume fractions of the metal powder to be incorporated in the …
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The Formulation of Titanium - based Metal Feedstocks and the Fabrication of Parts using the Powder Injection Moulding Process
… and holds the key to such innovation. Titanium metal parts were fabricated by injection moulding titanium based metal powder feedstock followed by a debinding process and subsequent sintering. The fabrication process in its entirety was investigated in four distinct steps. Feedstock formulation …
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Heat transfer model for the ignition of metal powder on a heated filament
The thermal processes leading to ignition of metal powders in environments that experience rapid temperature changes are currently poorly understood. In this research, a methodology for studying and quantification of such processes is developed. In the experimental case study, the ignition …
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Sintering and Characterizations of 3D Printed Bronze Metal Filament
Metal 3D printing typically requires high energy laser or electron sources. Recently, 3D printing using metal filled filaments becomes available which uses PLA filaments filled with metal powders (such as copper, bronze, brass, and stainless steel). Although there are some studies on their …
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A review of optical diagnostic techniques used to identify uranium spectral signatures
… graphite electrode sparks containing powders, uranium wire electrode sparks, and ignition of various metal powders to generate burning dust clouds. High-speed images of two out of the three excitation methods are reported. Additionally, the initial gas environments and pressures will …
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