Rapid Consolidation by Spark Sintering of Rapidly Solidified 7075 Aluminum Alloy Powder |
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| Authors: | K. Matsugi Y. Wang T. Hatayama O. Yanagisawa M. Kiritani |
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| Affiliation: | 1. Department of Mechanical Materials Engineering , Hiroshima University , Kagamiyama 1-4-1, Higashi-Hiroshima, Hiroshima, 7398527, Japan;2. Academic Frontier Research Center for Ultra-high Speed Plastic Deformation , Hiroshima Institute of Technology , Miyake 2-1-1, Saeki-ku, Hiroshima, 7315193, Japan |
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| Abstract: | Compacts of 7075 aluminum have been produced from rapidly solidified powders by optimizing spark sintering parameters, such as pulse discharge time, fixed maximum temperature, holding time at this temperature, and method of cooling to room temperature after the sintering. High-grade compacts can be obtained by a short process (40-50 s) consisting of heating to 773 or 873 K at a heating rate of 9.6 K/s and holding this temperature for 10 s. The rapidly cooled compacts show the same supersaturated state at room temperature as the received as-atomized powder. Compacts quenched in water just after spark sintering at 873 K for 1.2 ks show the same age-hardening behavior as solution-heat treated compacts. Compacts that are quenched in water and aged after sintering at 873 K for 1.2 ks show the same elongation and flow stress as compacts aged after solution heat treatment. Elongation data suggest that compacts produced with longer holding time at a higher temperature and rapid cooling show a large amount of main alloying elements in solid solution and sufficient promotion of sintering. |
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| Keywords: | Rapid Solidification 7075 Aluminum Powder Spark Sintering Supersaturated Solid Solution Direct Current Pulse Discharge Consolidation |
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