浇注温度和Sr变质剂添加量对AlSi7Mg合金流动性的影响  

Influence of Pouring Temperature and Sr Modification on the Flowability of AlSi7Mg Alloy

作　　者：马俊成[1] 夏少华[1] 周峰[1] 王沛培[1] 白云[1] 谭东[1] 

机构地区：[1]南车戚墅堰机车车辆工艺研究所有限公司,江苏常州213011

出　　处：《机车车辆工艺》2012年第6期1-2,9,共3页Locomotive & Rolling Stock Technology

摘　　要：采用同心三螺旋测试装置,研究了不同的浇注温度、不同的Sr添加量对AlSi7Mg合金流动性的影响。研究结果表明:随着浇注温度的提高,合金的流动性显著增加,对于大型薄壁铸件浇注温度不宜过低,浇注温度低,合金的流动性大大下降,可造成铸件浇不足及冷隔等铸造缺陷;随着浇注温度提高,合金中枝晶α-Al变得逐渐粗大,硅相从分散变得聚集,这对合金组织不利,所以浇注温度不易偏高;随着Sr添加量的增加,AlSi7Mg合金的流动性有所提高,但提高幅度不大。The influence of different pouring temperatures and Sr additions on the flowability of AlSi7Mg alloy is studied with a concentric triple helix device. Testing findings indicate that the flowability of the alloy increase dramatically with the increase of the pouring temperature. In terms of large sized thin - walled casting, a too low pouring temperature could resuh in a decrease of alloy fluidity and consequently casting defects, such as cold shuts and misrun. As the pouring temperature goes up, the tree - like crystal α - Al grows thicker and Si phase becomes aggregated, which is unfavorable to the alloy structure. A not too high pouring temperature, therefore, can improve the fluidity with the increase of Sr addition, although the improvement is not so much.

关 键 词：ALSI7MG合金 流动性 Sr变质剂 浇注温度 

分 类 号：TG146[一般工业技术—材料科学与工程]