晶界工程调控Inconel 718合金晶界处δ相的析出  

Precipitation of theδPhase at Grain Boundary in Inconel 718 Alloy after Grain Boundary Engineering

作　　者：王素珍 陈伟平 张孟超 李慧[1] WANG Suzhen;CHEN Weiping;ZHANG Mengchao;LI Hui(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444

出　　处：《精密成形工程》2024年第10期131-138,共8页Journal of Netshape Forming Engineering

基　　金：国家重点研发计划(2016YFB0700401)。

摘　　要：目的针对镍基Inconel 718合金在高温服役时强化相转化为晶界δ脆性相从而降低服役性能的问题,通过热机械处理工艺调整晶界脆性相的析出和分布,以提升合金在高温环境下的耐用性和服役性能。方法通过晶界工程(GBE)技术提高样品中低Σ重位点阵(CSL)晶界的比例,调整晶界处δ相的分布规律。利用扫描电子显微镜(SEM)和电子背散射衍射(EBSD)技术分析样品的显微组织演化规律。结果GBE处理使样品中低ΣCSL晶界比例较固溶态的54.34%提高至81.43%,显著优化了晶界特征分布。通过SEM分析了δ相在不同类型晶界处的分布特征:较小的δ相沿平行于Σ3c晶界两侧分布、沿垂直于Σ3i晶界两侧分布,沿Σ9晶界一侧呈针状分布;较大的δ相沿Σ27晶界一侧呈短棒状或层片状分布,在随机晶界处杂乱分布。GBE处理后合金的塑性显著提升,其延伸率从固溶态的21.1%提升至GBE态的26.6%。结论通过晶界工程技术提升了镍基合金中低ΣCSL晶界的比例,调整了晶界处δ相的析出规律,优化了Inconel 718合金的微观结构,从而有望提高其在高温环境下的服役性能。Aiming at the problem that in nickel-based Inconel 718 alloy,the strengthening phase is transformed into the grain boundaryδbrittle phase during high temperature service,reducing the service performance,the work aims to conduct a research on adjusting the precipitation and distribution of grain boundary brittle phases through thermomechanical treatment processes to improve the durability and service performance of the alloy in high temperature environments.Grain boundary engineering(GBE)was employed to enhance the prevalence of lowΣCSL grain boundaries within the sample and refine the distribution pattern of theδphase at the grain boundaries.Scanning electron microscopy(SEM)and electron backscatter diffraction(EBSD)were used to analyze the microstructure evolution of the sample.GBE treatment increased the proportion of lowΣCSL grain boundaries in the sample from 54.34%in the solution state to 81.43%,optimizing the distribution of grain boundary characteristics.SEM analysis revealed the distribution characteristics of theδphase at different types of grain boundaries:smallerδphases distributed at both sides ofΣ3c grain boundary when parallel to each other,evolved at both sides of matrix when perpendicular to theΣ3i grain boundary and distributed in needle shape at only one side ofΣ9 grain boundary.Largerδphases distributed in a short rod or flake shape atΣ27 grain boundaries,and randomly distributed at random grain boundaries.GBE treatment significantly enhanced the ductility of the alloy and increased the elongation rate to 26.6%from 21.1%of solution sample.By employing grain boundary engineering technology,this study increases the proportion of lowΣCSL grain boundaries in the nickel based alloy,adjusts the precipitation pattern of theδphase at grain boundaries,and optimizes the microstructure of the Inconel 718 alloy,which is expected to improve its service performance in high temperature environment.

关 键 词：Inconel 718合金 镍基合金 晶界工程 晶界类型 Δ相 

分 类 号：TG113[金属学及工艺—物理冶金]