抄録
In order to clarify the effects of strontium and phosphorus on eutectic cell count and morphology in high purity Al-7% Si alloys, the quench technique was applied, and eutectic cells were observed on the contact surface with the mold. In addition, the eutectic solidification starting temperature was measured. The results are as follows. The eutectic solidification starting temperature decreases with the addition of strontium. Strontium does not change the number of eutectic cells of the alloy without phosphorus, but decreases the number of eutectic cells of the alloy with phosphorus. Protrusions were observed on the solid-liquid interface of the alloy without strontium, whose shape resembled the leaf veins of plants. On the other hand, the solid-liquid interface of alloys added with strontium was smooth. The curvature of the eutectic silicon with the addition of strontium may be due to the formation of strontium-rich, low eutectic temperature liquidus film in front of the eutectic solid-liquid interface.
