Effect of the Extrusion Ratios on Fiber Breakage and Orientation in Hot Extrusion Process in Metal Matrix Composites

금속복합재료의 열간압출공정에 있어서 압출비가 섬유의 파단 및 배향에 미치는 영향

The aluminar short fiber reinforced composite materials for hot extrusion were fabricated by semi-solid stirring method, and extruded at extrusion temperature $400^{\circ}C$ with various extrusion ratio. The hot extrusion load of volume fraction 15% metal matrix composites and base alloy Al7075 has been compared. The fiber length distribution, fiber breakage and fiber orientation are investiged to know the fiber behaviour in before and after hot extrusion. The tensile strength of the hot extruded billet are experimentally determined for different of extrusion ratios, and compared with theorically calculated strength.