镍基高温合金不完全动态再结晶组织对力学性能的影响及断裂机制  

Effect of Incomplete Dynamic Recrystallization Microstructure on MechanicalProperties and Fracture Mechanism of Nickel-based Superalloy

作　　者：王淼 刘延辉 刘昭昭[1] WANG Miao;LIU Yanhui;LIU Zhaozhao(School of Mechanical and Electrical Engineering,Shaanxi University of Science and Technology,Xi’an 710021,China;School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China;Zhejiang Wenzhou Research Institute of Light Industry,Wenzhou 325002,Zhejiang,China)

机构地区：[1]陕西科技大学机电工程学院,西安710021 [2]西北工业大学材料科学与工程学院,西安710072 [3]浙江温州轻工研究院,浙江温州325002

出　　处：《材料导报》2024年第6期217-221,共5页Materials Reports

基　　金：国家自然科学基金(51805308);中国博士后科学基金(2018M631189);陕西省自然科学基金(2019JQ-303,2018JQ5161);温州市科技项目(G20180032)。

摘　　要：本工作对热等静压态镍基高温合金FGH4096在变形温度为1 080℃、应变速率为3 s^(-1)的条件下进行等温变形,最大变形量为50%,进而研究高温变形过程中该合金组织演变规律,并选取具有典型形变组织的区域在700℃、0.001 s^(-1)条件下进行力学性能测试。基于光学显微镜(OM)、扫描电镜(SEM)和电子背散射衍射技术(EBSD)对显微组织和断口的分析测试结果,发现热变形过程中产生的不完全动态再结晶组织从试样截面中心到边缘区域再结晶程度依次降低,中心部位抗拉强度可达到1 422.79 MPa,屈服强度为1 110.3 MPa,延伸率为10.15%。再结晶晶粒形核首先发生在晶界处,形核方式主要为晶界凸出形核。不完全动态再结晶组织中的变形晶粒内部存在亚晶界,对位错的运动起到阻碍作用,使得合金强度提高。合金断口形貌为韧窝状和撕裂棱的混合结构,断裂方式为穿晶断裂。The isothermal deformation of hot isostatic pressed nickel-based superalloy FGH4096 was carried out at 1080℃and 3 s^(-1) strain rate,and the maximum deformation was 50%.The microstructure evolution of the alloy during high temperature deformation was studied,and the mechanical properties of the region with typical deformation microstructure were tested at 700℃and 0.001 s^(-1).Meanwhile,the microstructure and fracture were analyzed by optical microscope(OM),scanning electron microscope(SEM)and electron backscatter diffraction(EBSD).It is found that the recrystallization degree of the incomplete dynamic recrystallization structure decreases from the center to the edge of the sample section,and the tensile strength of the center region is 1422.79 MPa,the yield strength is 1110.3 MPa and the elongation is 10.15%.The nucleation of recrystallized grains first occurs at grain boundaries and the nucleation mode is mainly protruding grain boundaries.In the incomplete dynamic recrystallized structure,there are subgrain boundaries in the deformed grains,which hinder the dislocation movement and improve the strength of the alloy.The fracture morphology is a mixture of dimple and tearing edge,and the fracture mode is transgranular fracture.

关 键 词：FGH4096合金 不完全动态再结晶 力学性能 断口分析 

分 类 号：TG113[金属学及工艺—物理冶金]