Counter-Gravity Casting Equipment and Technologies for Thin-Walled Al-Alloy Parts in Resin Sand Molds

Abstract

A counter-gravity casting equipment (CGCE) has been developed, which is specially designed for the production of large-size thin-walled high-quality aluminum alloy parts with resin sand molds. In this equipment, molten metal will be pushed upward counter-gravity into the mold at predetermined rate by compressed air, and solidified at an increased pressure. The equipment uses assembled valve system developed ourselves, and has sensitive pressure-adjusting property. All of the casting parameters, including filling rate, pressure-exerting sequence, pressure hold time etc., can be closely controlled by a self-designed computer program. Up to 2 ton casting can be produced with the equipment. Compared to the castings produced under conventional gravity conditions, the castings under counter-gravity condition have generally high soundness, higher tensile strengths and ductility. The pinhole defects are also degraded obviously. The equipment and the technology have been widely adopted by several users in China for the production of large-size thin-walled aluminum alloy castings with high property requirements.