摘要
单晶高温合金是一种复杂组元多相组织材料,随着合金化程度的不断提高、难熔元素的增多和叶片结构的复杂化与大型化,凝固缺陷控制成为提高叶片质量和性能的关键.单晶合金的凝固组织及凝固缺陷不仅与合金成分有关,还取决于其凝固特性及工艺条件,本文阐述了先进单晶合金固/液相变温度、凝固分配系数等凝固特性的特点和变化规律,重点分析了晶体取向偏离和杂晶2种典型凝固缺陷形成机制及其与凝固特性、工艺条件的关系,探讨了解决复杂单晶叶片典型缺陷的方法和思路,并评述了不同控制方法的实施效果.
Single crystal（SC） superalloy is a kind of complex structure and multi phase materials. With the increase of the degree of alloying and the content of refractory elements, or the more complicated structure and larger size of the casting made of SC superalloy, it is essential important to suppress the formation of solidification defects to improve the quality and performance of the blades. The microstructure and solidification defects of single crystal alloy are not only related to the composition of the alloy, but also depend on its solidification characteristics and technological conditions. The paper first summarizes the research progress of the solidification characteristics for advanced SC superalloys, focusing on analysis of the effects of solidification characteristics and processing parameters on the formation and its mechanics for two typical directional solidification defects, crystallographic orientation deviation and stray grains. Then some methods and approaches to suppress such defect formation for complex single crystal blade have been reviewed.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第10期1163-1178,共16页
Acta Metallurgica Sinica
基金
国家高技术研究发展计划项目2012AA03A511
国家自然科学基金项目51331005和50931004
国家重点基础研究发展计划项目2011CB610406
西北工业大学基础研究基金项目2014JM6227资助~~
关键词
单晶高温合金
凝固特性
凝固缺陷
single crystal superalloy
solidification characteristic
solidification defect
