大规格Ti80合金棒材冲击韧性各向异性研究  

Study on Impact Toughness Anisotropy of Large Size Ti80 Alloy Bar

作　　者：汪启明 杨晶 陈海生[1,2] 刘向宏[1,2] 王涛 何龙龙[1,2] 王凯旋 罗锦华[1,2] Wang Qiming;Yang Jing;Chen Haisheng;Liu Xianghong;Wang Tao;He Longlong;Wang Kaixuan;Luo Jinhua(National&Local Joint Engineering Laboratory for Special Titanium Alloy Processing Technologies,Western Superconducting Technologies Co.,Ltd.,Xi’an 710018,China;Xi’an Key Laboratory of Special Titanium Alloy Processing and Simulation Technologies,Xi’an 710018,China;Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西部超导材料科技股份有限公司,特种钛合金材料制备技术国家地方联合工程实验室,陕西西安710018 [2]西安市特种钛合金制备及仿真技术重点实验室,陕西西安710018 [3]西北工业大学,陕西西安710072

出　　处：《钛工业进展》2023年第5期9-14,共6页Titanium Industry Progress

摘　　要：针对大规格Ti80合金棒材冲击韧性各向异性现象及其内在原因进行了系统研究。夏比冲击试验显示,棒材R/2处弦向的C-R试样(缺口所在面与棒材轴向垂直)的冲击韧性远高于C-L试样(缺口所在面与棒材轴向平行)。金相组织结果表明,热处理态Ti80合金棒材横截面显微组织主要由均匀的等轴状初生α相组成,而纵截面组织中还存在与棒材轴向平行的长条状初生α相;冲击断口扫描电子显微镜(SEM)结果表明,C-R试样断面起伏更为剧烈,断面处存在大量横向裂纹,裂纹扩展方向垂直于长条状初生α相,长条状初生α相起到阻碍裂纹扩展的关键作用,从而冲击韧性明显高于C-L试样;断口侧面(与缺口所在面垂直的侧面)背散射电子衍射(EBSD)结果显示,C-R试样在裂纹萌生及扩展的过程中发生了更为严重的塑性变形,这个过程需要消耗更多能量,从而具有更高的冲击韧性。The impact toughness anisotropy of large size Ti80 alloy bar and its internal causes were systematically studied in this paper.Charpy impact test results show that the impact toughness of C-R specimen(the notch surface is perpendicular to the axial direction of the bar)at R/2 position is much higher than that of C-L specimen(the notch surface is parallel to the axial direction of the bar).The metallographic result shows that the transverse microstructure of the heat-treated Ti80 alloy bar is mainly composed of equiaxed primaryαphases,while there are also elongated primaryαphases parallel to the bar axis in the longitudinal structure.The results of impact fracture scanning electron microscopy(SEM)indicate that the cross-section of C-R specimen undulates more violently,there are a large number of transverse cracks at the cross-section,the crack growth direction is perpendicular to the elongated primaryαphases,and the long strip primaryαphases play a key role in hindering crack propagation,thus showing significantly higher impact toughness than C-L specimens.The results of electron back scatter diffraction(EBSD)on the side of the fracture(perpendicular to the notch surface)show that the C-R specimen experienced more severe plastic deformation during the initiation and propagation of cracks,this process consumes more energy and thus has higher impact toughness.

关 键 词：Ti80合金 冲击韧性 各向异性 断裂 微观组织 

分 类 号：TG146.23[一般工业技术—材料科学与工程]