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pISSN : 1598-706X / eISSN : 2288-8381


(논문)연구논문

한국주조공학회지 (11권4호 293-302)

Characteristics of Al_2O_3 Short Fiber/Al-Si-Mg Alloy Composites Fabricated by Rheo-compocasting and Hot Extrusion

Rheo-compocasting 및 열간압출에 의하여 제조한 Al-Si-Mg / $Al_2O_3$ 수식 이미지단섬유강화복합재료의 특성

Hag-Ju Lee*, Chun-Pyo Hong**

*Dongmyung Junior College, **Yonsei University

Abstract

Aluminum alloy matrix composites reinforced with various amounts of Al_2O_3 short fibers have been produced by a combined technique of rheo-compocasting and hot extrusion. Distribution of fibers in the composites fabricated by rheo-compocasting was relatively uniform. A good degree of uniaxial fiber alignment has been achieved by hot extrusion, but a lot of fibers fractured during extrusion. The tendency of fiber fracturing increases as the aspect ratio and the amount of fibers increase. Relatively good bonding between fiber and matrix was obtained by the formation of MgAl_2O_4 and Mg(Al, Fe)_2O_4 at the interface between fiber and matrix. In extruded composites, fiber-strengthening effect was relatively small since a lot of fibers fractured during hot extrusion. On the other hand, dispersion strengthening effect may increase. In order to improve the fiber strengthening effect, it is important to optimize the extrusion condition with consideration of metal flow in extrusion die.

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