Semi-solid die casting process with three steps die system

In automobile suspension part, knuckle as functional component is very complex shape and required high strength. To manufacture the high strength component like knuckle with semi-solid die casting process, there are required reheating condition, casting plan, die design, injection condition, defect analysis and measurement of mechanical properties. In this study, aluminum knuckle with semi-solid die casting process was developed to replace the conventional steel components. Semi-solid die casting was established to lead the laminar flow and pressure transfer to the end point of product and to avoid oxide skin and shrinkage porosity. Three steps die system was made up two-step moving die and biscuit cutting system. And that was suitable for center-positioned gate and designed to hold the similar filling length and applying pressure. Aluminum knuckle component made by three steps die system designed by casting simulation. Also, injection condition was established to remove oxide skin and liquid segregation. After controlled above process parameters, tensile strength, yield strength, elongation and microstructure were investigated to verify the real automobile applicability.