Al-3.6%Cu合金定向凝固一次枝晶间距选择  

Selection of Primary Dendritic Spacing During Directional Solidification of Al-3.6%Cu

作　　者：李林蓄[1] 林鑫[1] 王猛 黄卫东[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造技术》2008年第7期891-895,共5页Foundry Technology

基　　金：国家自然科学基金(50771083)资助

摘　　要：采用A1-3.6%Cu单相固溶体合金,进行了较为全面的定向凝固淬火实验,考察了籽晶选取对合金凝固界面形态及一次枝晶间距的影响,并进一步分析了一次枝晶间距随凝固速度的演化规律。研究发现,籽晶的选取对于定向凝固的界面晶体取向和一次枝晶间距具有重要的影响,平均一次枝晶间距随着凝固速度的增大逐渐减小,且存在一个较宽的容许范围。实验结果与HL模型及LIN自洽模型计算获得了较好吻合,而KGT模型明显高估了实验值。Al-3. 6% Cu alloys were directionally solidified with constant and step-varing pulling velocity. The effect of the seed crystal on the morphological evolution was investigated, and the selection of primary dendritic spacing with the solidification velocity was further studied in detail during directional solidification of Al-3.6%Cu alloy. It is found that the seed crystal has an important effect on the crystallographic orientation and primary dendritic spacing during directional solidification. With increasing growth velocity, the average primary spacing decreases and there exists a wide allowable range for primary dendritic spacing. The experimental results of primary dendritic spacing agrees well with that predicted by HL and Lin＇s self-consistent model, while KGiT model over-estimates the experimental results.

关 键 词：定向凝固 一次枝晶间距 历史相关性 

分 类 号：TG27[金属学及工艺—铸造]