论文部分内容阅读
通过对Al-7.2Zn-2.2Mg-1.8Cu合金进行直接挤压铸造成形,研究了挤压铸造过程中凝固组织偏析的分布规律。结果表明,挤压铸造凝固组织存在较为严重的宏观和显微偏析,压力作用导致铸件心部富含溶质元素,形成宏观异常偏析;晶内枝晶和晶间共晶相成分差异形成显微偏析,且挤压铸造提高了凝固速度,降低了显微偏析的程度。
Al-7.2Zn-2.2Mg-1.8Cu alloy by direct extrusion casting forming, squeeze casting process of solidification segregation distribution. The results show that there are some macroscopic and microscopic segregations in the solidification structure of squeeze casting. The pressure causes the heart of castings to be enriched with solute elements and form macroscopic anomalous segregation. The intragranular dendrites and intergranular eutectic phases form micro-segregation , And squeeze casting to improve the solidification rate, reducing the degree of micro-segregation.