DZ411合金长期时效后γ′相演变的非线性超声表征  

Nonlinear ultrasonic characterization ofγ΄phase evolution in DZ411 alloy after long-term aging

作　　者：杨罡正亮 李萍[1] 曹铁山[1] 赵杰[1] YANG Gangzhengliang;LI Ping;CAO Tieshan;ZHAO Jie(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116024

出　　处：《材料工程》2025年第4期143-149,共7页Journal of Materials Engineering

基　　金：航空发动机及燃气轮机基础科学中心项目(P2021-A-Ⅳ-001-001);船用燃气轮机基础研究项目(MGT2023001);国家自然科学基金项目(51901035)。

摘　　要：为了探索非线性超声方法在定向凝固镍基高温合金时效组织演变中应用的可行性,以DZ411定向凝固镍基高温合金为研究对象,利用非线性超声检测技术,结合扫描电子显微镜与X射线衍射分析等组织分析手段,对不同时效状态下的DZ411合金进行微观形貌观察、γ΄相定量表征、非线性超声检测和晶格错配度分析等,探讨非线性超声系数与组织演变定量参数之间的相关性。结果表明:随着时效时间的延长,γ΄相的尺寸逐渐增大,形状由立方状向类球状转变,立方度下降,粒子密度减小,归一化非线性超声系数呈指数规律单调递增;非线性超声系数与晶格错配度、γ΄相等效直径呈现正相关,与面积分数呈现负相关。分析认为上述现象的产生归因于:时效过程中,由于发生合金元素的充分扩散和两相界面处溶质原子再分配,使得γ΄相长大及两相共格界面处的晶格应变增大,所形成的局部应力应变场进一步干扰超声波传播特性,加剧两相界面处的超声波畸变,从而促进谐波成分的产生和非线性效应的增强。To explore the feasibility of the nonlinear ultrasonic method in the aging microstructure evolution application of directionally solidified nickel-based superalloy,DZ411 directionally solidified nickel-based superalloy is studied.The microstructure observation,γ΄phase quantitative characterization,nonlinear ultrasonic detection,and lattice mismatch analysis of DZ411 alloy under different aging conditions are carried out by using nonlinear ultrasonic detection technology,combined with SEM and XRD.The correlation between nonlinear ultrasonic coefficient and quantitative parameters of microstructure evolution is discussed.The results show that with the extension of aging time,theγ΄phase size increases,theγ΄phase changes from cubic to spherical,the cubic degree decreases,the particle density decreases,and the normalized ultrasonic nonlinear coefficient increases exponentially.The nonlinear ultrasonic coefficient is positively correlated with the lattice mismatch,and theγ΄phase equivalent diameter,and negatively correlated with theγ΄phase area fraction.The analysis shows that the above phenomenon is attributed to the full diffusion of alloying elements and the redistribution of solute atoms at the two-phase interface during the aging process,increasing theγ΄phase size and the lattice strain at the two phase intorface,enhancing the interference of the local stress-strain field on the propagation characteristics of the ultrasonic wave and aggravating the distortion of the ultrasonic wave at the two-phase interface,thus promoting the generation of harmonic components and the enhancement of nonlinear effects.

关 键 词：镍基高温合金 时效处理 定量表征 非线性超声 晶格错配度 

分 类 号：TG156.92[金属学及工艺—热处理] O422.7[金属学及工艺—金属学]