镍基单晶高温合金孔洞缺陷数值模拟与控制方法研究进展

Modeling and Control of Porosity Defects in Nickel-Based Single Crystal Superalloys:A Review

镍基单晶高温合金是高性能航空发动机涡轮叶片的主要材料,其孔洞缺陷是影响涡轮叶片服役可靠性与耐久性的关键因素。常规试验分析手段往往只能获得定性规律,而多尺度数值模拟技术和三维形态表征技术的快速发展,为研究镍基单晶高温合金孔洞形成和演化机理以及精确预测孔洞缺陷的几何特征、分布方式和含量提供了条件。总结了国内外铸态孔洞、固溶孔洞和服役中孔洞缺陷形成与演化的数值模拟研究进展,评述了目前孔洞缺陷预测模型的使用条件和局限性,指出了从铸造到服役全流程孔洞演化与预测精确化、定量化研究所存在的问题,并展望了镍基单晶高温合金孔洞缺陷多尺度数值模拟技术的发展方向。

Nickel-based single crystal superalloy is one of the key materials for turbine blades used for current aeroengines.The porosity defect has a significant influence on the reliability and durability of turbine blades.Conventional experimental analysis is often limited by qualitative rules.Recent developments of numerical simulation and threedimensional characterization techniques facilitate to reveal the formation and evolution mechanisms of porosity defects in Ni-based single crystal superalloys and precisely predict their geometrical features,distribution,and volume fraction.Here we review the research progress on the numerical simulation of porosity defects,and discuss the features of current porosity prediction models.To provide possible guidances for multiscale modeling of porosity formation in nickel-based single crystal superalloys,the potential barriers that prevent quantitative prediction and control of porosity defects from casting to final service are proposed.