Optimal Control of Chill layers through Regulation of Temperature on Shot Sleeve in Aluminum High Pressure Diecasting

Al고압주조공법에서 사출슬리브 온도 조절을 통한 Chill layer의 최적 제어

In this study, the effect of chill layers occurred in shot sleeve on the molten metal filling was analyzed through computer simulation. The behavior of chill layers with temperature variation of shot sleeve set from 200 to $280^{\circ}C$ was also investigated. The simulation results showed the chill layers set in the in-gates during the injection process change the main filling direction and cause turbulent flow pattern, resulting in porosities inside the castings. The amount of chill layers with the increasing temperature of shot sleeve was considerably reduced. Particularly, at the setting temperature of $280^{\circ}C$ by heat control unit, the biggest reduction in chill layers, excellent trimmed surface and the highest density were achieved, suggesting that as the optimal sleeve condition in aluminum high pressure diecasting, especially for highly complex parts like valve body.