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从金属组织遗传性原理出发,使用同种成分的细晶合金作为中间合金来细化水平连铸Al-18Si合金的组织。利用扫描电镜(SEM)、差式扫描热分析(DSC)等研究了细晶中间合金含量对Al-18Si合金组织及其均匀性的影响。结果表明,细晶中间合金可以有效减小Al-18Si合金锭初生Si尺寸,提高其铸锭横截面上组织的均匀性。加入细晶中间合金后初生Si形核温度提高,释放的结晶潜热减少;中间合金的加入还可以明显改善合金凝固过程对冷却速度的敏感性,减少合金铸锭表面和中心凝固曲线上初生Si的析出温度差。
Based on the hereditary principle of metal organization, the fine-grained alloy with the same composition was used as the intermediate alloy to refine the microstructure of the horizontal continuous casting Al-18Si alloy. The microstructure and homogeneity of Al-18Si alloy were studied by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results show that the fine grained master alloy can effectively reduce the size of primary Si in Al-18Si alloy ingots and improve the homogeneity of the ingot cross-section. The temperature of the primary Si nucleus increases after the addition of the fine-grained master alloy, and the latent heat of crystallization released decreases. The addition of the master alloy can also significantly improve the sensitivity of the alloy to the cooling rate during the solidification process, and reduce the formation of primary Si on the surface and center of the alloy ingot Precipitation temperature difference.