| The purpose of this study is to establish hot extrusion variables for the powder metallurgy (P/M) processed 2009 Al-SiCw composites and to evaluated tensile properties of extruded composite bars. In order to extrude Al-SiCw billets, 550 ton hot extruder was used, and extrusion variables such as billet temperature, die temperature, ram speed and reduction ratio were investigated. Experimental results indicated that formation of circumferential cracks was associated with fast ram speeds and/or high die temperatures, suggesting that low ram speeds and low die temperatures are required to prevent, the circumferential cracks. Using the extrusion temperature of 450∼500℃ under the extrusion pressure of 700∼1000㎫, composite billets were extruded to bars having relatively homogeneous microstructures. Mechanical properties of the extruded bars were found to be comparable with those of composite processed by Advanced Composite Materials Corp. |
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