高文理 毛郭灵 刘东洋 袁航 高艳丽

摘   要：ZL114A合金是由北京航空材料院自主研发的铸造亚共晶Al-Si合金，合金铸锭的孔隙率、微观气孔的分布位置及形貌对合金的力学性能有很大的影响. 利用密度测量仪，SEM结合EDX，研究了砂型铸造条件下，Y元素对ZL114A合金铸锭的孔隙率、微观气孔的分布及形貌的影响. 结果表明，由于Y元素的原子序数较大，ZL114A合金的理论密度和实际密度都有少量增加;同时合金的孔隙率下降，铸锭微观气孔的分布位置由分布于整个合金基体中变为多分布于共晶区域;微观气孔的形貌由颗粒状、网络状共同存在变为以网络状存在为主;虽然Y元素对合金铸锭的孔隙率、微观气孔的分布位置以及形貌都有影响，但不是通过直接与合金熔体中的气体作用来发挥作用的.

关键词：ZL114A合金;Y元素;密度;微观气孔

中图分类号：TG146.21                         文献标志码：A

Effects of Y Element on Micro-pores of ZL114A Alloy

GAO Wenli1?，MAO Guoling1，LIU Dongyang1，YUAN Hang1，GAO Yanli2

（1. College of Materials Science and Engineering，Hunan University，Changsha 410082，China;

2. Beijing Institute of Aeronautical Materials，Beijing 100095，China）

Abstract：ZL114A alloy is a casting hypoeutectic Al-Si alloy independently developed by Beijing Institute of Aeronautical Materials. The porosity， distribution and morphology of micro-pores have a great influence on the mechanical properties of the alloy. Using density measuring instrument， SEM with EDX， the effects of Y element on the porosity， distribution and morphology of micro-pores of ZL114A ingot were studied in sand casting conditions. The results showed that with the addition of Y，because the Y atomic number is larger，the theoretical density and actual density of ZL114A alloy increased slightly. At the same time，the porosity of the alloy  decreased， and the distribution of micro-pores changed from being distributed throughout the alloy matrix to being more distributed in the eutectic region， and the morphology changed from coexistence of particles and networks to network-based ones. Although the Y element had an effect on the porosity， distribution and morphology of micro-pores， the Y element did not  play a role by directly interacting with gases in the alloy melt.

Key words：ZL114A alloy;Y element;density;micro-pores

ZL114A合金具有優异的铸造性能，较低的热膨胀系数，良好的耐腐蚀性、耐磨性以及综合力学性能，被广泛应用于航空航天工业和汽车工业，尤其适合大型薄壁复杂结构铸件的生产，如发动机燃油壳体[1-3]. ZL114A合金由初生α-Al和共晶组织组成，共晶组织包括共晶Al和共晶Si，硬度很高的Si相对铝基体起到了很好的强化作用. 在未变质的合金中，共晶Si相呈粗大的板片状，塑性变形的过程中，板片状的Si尖角处很容易发生应力集中，导致基体开裂，合金断裂. 变质共晶Si，将共晶Si由粗大的板片状变质为细小的纤维状、珊瑚状等，是提高……