7A52合金铸锭漏斗底结物形成原因

7A52合金铸锭时,分液漏斗底部常产生底结物。通过化学及SEM-EDS分析,发现底结物中Mn、Cr、Ti元素浓度分别超正常值约5倍、10倍、15倍。XRD分析表明其主要化合物相组成为Al7Cr、MnAl6、TiAl3。结果表明,底结物产生和形成原因主要与分配漏斗与液穴底的间距、分配漏斗的材质、铝熔体中的杂质等因素有关,同时也与铸造温度、分配漏斗预热等工艺条件有关。根据分析结果,提出了提高铸造速度、改变分配漏斗尺寸、对分配漏斗进行喷涂和预热等消除底结物的具体措施,并成功应用于生产实践。

Research on Bulky Compound of 7A52 Alloy Ingot under Funnel

When 7A52 ingot is casting, agglomerate intermetallic compounds form in the bottom of separatory funnel. By chemical and SEM-EDS analysis, the element concentrations of Mn, Cr, Ti in intermetallic compounds are 5, 10, 15 times above normal values respectively. It is suggested that compounds are mainly comprised of Al7Cr, MnAl6 and TiAl3 phase through X-ray diffraction analysis. Results indicate that the formation of the bulky compounds is related to the factors like the distance between the separatory funnel and the bottom of melted sump, the material properties of separatory funnel and the impurity of melted aluminum, as well as the process conditions like casting temperature and the proper preheat of separatory funnel. Based on analysis results, concrete suggestions as increasing the casting rate, changing the size of separatory funnel, spray painting and preheating to separatory funnel and so on are proposed to relieve the agglomerate intermetallic compounds and applied into practice successfully.