ダイカスト鋳物のゲート近傍部の鋳造欠陥と流速

抄録

Behaviors of the molten metal in practical disk and plate-like die cavities were investigated by the use of metal flow sensors newly developed. Density distribution in the die castings was measured. Water and molten AC4B alloy analogues of metal flow respectively in rectangular transparent resin and metal molds were also performed. The slow/fast shot velocity changing point is located in the runner. The molten metal flows through the gate at a rate as fast as 15 to 20m/s. The flowing metal entraps gases near the gate resulting in internal defects. The volume of entraped gases and also internal defects are reduced by slowing down the metal velocity through the gate or transferring the slow/fast shot velocity changing point into the die cavity.