Al-P-RE-Sr复合变质过共晶铝硅合金

Al-P-RE-Sr Combination Modifier Hypereutectic Al-Si Alloy

研究了A l-P-RE-Sr复合变质剂对A l-30%S i合金组织的影响。经变质处理后,可使初晶硅长时间成弥散状态,不发生聚集,平均尺寸不超过35μm,同时共晶硅也被细化成纤维状或点状,变质长效性可达7 h以上。变质后石墨型与金属型浇注对变质效果的影响无太大区别。材料的力学性能也得到了提高,抗拉强度达到234.3MPa,伸长率达3.0%。

The effect of Al - P - RE - Sr combination modification on the structure of Al - 30% Si alloy is studied. After modification, the primary Si phase will be in dispersion state for a long time without congregation. The average grain size of primary Si phase is not be greater than 20 μm. At the same time,the eutectic Si is also in the shape of fibre or spot. The combination modification time can reach 7 hours. The effect of the black lead mold is not different from the metal mold. The mechanics capability of the material is improved with the strength σb reaching to 234.3 MPa and the ductibility δ reaching to 3.0%.