2219铝合金大直径圆锭铸造性能分析及其改进措施

摘要

In order to meet the need of large specification 2219 aluminium alloy ring for the new-generation launch vehicles, the large diameter 2219 aluminium alloy round ingot was developed. But with the increase of ingot diameter, the solidification cooling rate reached a lower level. Then casting defects, such as coarse grain size, the unevenly distribution of alloy composition and second phase, the lower levels solid solution of main micro-alloy element, a lot of intermetallic compounds and so on, appeared in the aluminium alloy ingot. In view of these problems, technical measures, including optimizing alloy composition, adjusting process parameters of semi-continuous casting, adopting ultrasonic casting process, using multi-homogenizing heat treatment, were proposed to improve the ingot quality.%为了满足新一代运载火箭用超大规格2219铝合金环件的需求，开展了2219铝合金大直径铸锭的研发。但是随着铸锭直径的增大，凝固冷却速度较低，因此出现了铸锭晶粒粗大、合金成分和第二相分布不均匀、主微合金元素固溶程度较低及大量粗大金属间化合物等铸造缺陷。针对这些问题，提出了优化合金化学成分、调整半连续铸造工艺、引入超声铸造、采用多级均匀化热处理等技术措施对铸锭质量进行改善。