冷却速率对Zn-27Al合金凝固组织的影响  

Effect of Cooling Rate on the Microstructural Evolution of Solidified Zn-27A1 Alloys

作　　者：包艳青[1] 杨红旺[1] 杨柏俊[2] 白彦华[1] 曲迎东[1] 李荣德[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870 [2]中国科学院金属研究所沈阳材料科学国家实验室,沈阳110016

出　　处：《材料导报（纳米与新材料专辑）》2011年第1期504-506,共3页

基　　金：国家自然科学基金(50874075);辽宁省教育厅重新团队项目(2009T077);沈阳市科技局项目(1091177-1-00)

摘　　要：研究了不同冷却速率对Zn-27Al合金微观组织结构的影响,用铜模喷铸法制备φ5mm、φ2mm、φ1mm圆柱试样,通过熔体急冷法制备条带样品,利用扫描电子显微镜和X光衍射仪分别观察其组织形貌、分析其试样的相组成并计算晶格常数。结果表明,不同冷却速率下组织形态会发生显著变化,随着冷却速率的提高,其形貌按河流状、树枝晶、规则网格状、无规则形貌逐步过渡并使组织变得细小致密均匀;快速凝固条件下,更多的Zn原子固溶在Al晶格中,改变了富Al相的晶面间距。The effect of cooling rate on the microstructural evolution of solidified Zn-27A1 alloys was studied. Cylindrical samples with a diameter of 1 ram, 2 mm and 5 mm were prepared by copper mould casting, and ribbons were prepared by melt spinning. The microstructures of the obtained samples were characterized by scanning electronic microscopy. The results show that the morphology and microstructures altered obviously with the cooling rate of solidification. The morphology of the alloys experienced a process of coarse dendrite or chrysanthemum-like, fine dendrite, regular latticework and fine grains. Further, the lattice parameter of a phase of rapidly solidified ribbon is remarkably smaller than that of other samples solidified at a lower cooling rate, which is attributed to the retention of extra Zn atom within the A1 lattice.

关 键 词：ZN-AL合金 快速凝固 微观组织 晶面间距 晶格常数 

分 类 号：TG249.7[金属学及工艺—铸造]