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