单晶高温合金涡轮叶片的常见凝固缺陷及控制方法

Common Solidification Defects and Inhibition Methods in Single Crystal Superalloy Turbine Blades

近年来,随着单晶涡轮叶片气冷结构的复杂化和尺寸的大型化,单晶叶片制备过程中容易出现选晶失败、取向偏离、条纹晶、大角晶界、缘板杂晶、再结晶、雀斑等多种凝固缺陷,导致单晶高温合金性能降低,造成叶片报废。为了减少这些凝固缺陷,提高单晶品质,获得结构完整的单晶组织,熟悉单晶叶片生长过程中的各种常见缺陷,掌握凝固缺陷的形成规律及其控制技术就显得尤为重要。针对这一现状,系统地介绍了单晶叶片生长过程中常见的凝固缺陷,以及凝固缺陷形成规律和控制方法,为减少单晶叶片缺陷,提高叶片品质和合格率奠定了坚实的理论基础,提供了有力的技术保障。

In recent years,with the complexity of the gas-cooled structure and the large-scale size of the single-crystal turbine blade,the production of single-crystal blade is more prone to crystal selection failure,orientation deviation,sliver,large angle grain boundary,stray grain in the platform,recrystallization,freckles and other defects,which lead to the reduction of high-temperature alloy performance of single crystal turbine blade,and eventually cause the scrapping of single-crystal blade.In order to reduce these defects in single crystal blade,improve the quality of single crystal,and obtain a complete structure of single crystal structure,it is very important to be familiar with various common defects in the production of single crystal blade,realize the formation rules of defects,and master the defect inhibition technology.On this basis,the common solidification defects in the production of single crystal blades,as well as the formation rules and inhibition methods of solidification defects were systematically introduced,which lays a solid theoretical foundation for reducing the defects of single crystal blades and improving the quality and qualification rate of blades,and provides a strong technical support.