摘要
研究了一种新型含Ru高代次单晶高温合金(DD476)室温至1200℃的拉伸性能,并对拉伸断口及其附近的微观组织演变进行分析。结果表明:该合金经过完全热处理后的γ'相趋于立方状,枝晶干与枝晶间γ'相尺寸分别为225和330 nm,且元素偏析得到大幅改善,仅Re和W仍存在部分偏析;随变形温度的升高,屈服强度、极限抗拉强度先升高后降低,而伸长率和断面收缩率表现出相反的现象,拉伸断口特征由类解理断裂趋转变为以韧窝为主的韧性断裂。室温拉伸时,合金的滑移系开动较少,呈单系滑移状态。拉伸温度升高到760和980℃时,更多滑移系被激活而产生交滑移。随着拉伸温度的升高,断口附近位错由绕过γ'相逐渐转变为切过γ'相,而且在980℃变形时开始产生γ'相筏化,温度升高致使位错促进γ'相筏化。当温度达到1200℃时,位错基本消失,同时γ基体通道内析出细小的二次γ'相。
The tensile properties of a novel high generation single crystal superalloy containing Ru(DD476)from room temperature to 1200℃and the microstructure evolution of the tensile fracture and its vicinity were studied.The results show that,after fully heat treatment,theγ′phase of the alloy after tends to be cubic,the sizes ofγ′phase in the dendritic core and dendrite region are 225 nm and 330 nm,respectively,and the element segregation is greatly improved,only Re and W still have partial segregation.With the increase of deformation temperature,the yield strength and ultimate tensile strength first increase and then decrease,while the elongation and reduction of area show the opposite phenomenon.The tensile fracture characteristics also change from quasi-cleavage fracture to ductile fracture mainly with dimples.During tensile testing at room temperature,the slip system of the alloy is less activated and presents a single-slip state.When the tensile temperature increases to 760℃and 980℃,more slip systems are activated and cross-slip occurs.With the increase of tensile temperature,the dislocations near the fracture gradually change from bypassing theγ′phase to cutting through theγ′phase.Moreover,the alloy began to show theγ'phase rafting when deformed at 980℃.The increase in temperature causes dislocations to promote the rafting of theγ′phase.When the deformation temperature reaches 1200℃,the dislocations basically disappear,and fine secondaryγ′phases are precipitated in theγmatrix channel.
作者
刘震
王志成
曾强
秦海龙
谢锦丽
江亮
张华
LIU Zhen;WANG Zhicheng;ZENG Qiang;QIN Hailong;XIE Jinli;JIANG Liang;ZHANG Hua(Institute for Advanced Studies in Precision Materials,Yantai University,Yantai 264010,China;Gaona Aero Material Co.,Ltd.,Beijing 100081,China;Beijing Key Laboratory of Advanced High Temperature Materials,Central lron and Steel Research Institute,Beijing 100081,China)
出处
《中国有色金属学报》
北大核心
2025年第3期891-902,共12页
The Chinese Journal of Nonferrous Metals
基金
国家重点研发计划资助项目(2024YFB3713800)
山东省自然科学基金资助项目(ZR2024JQ020)
山东省泰山学者工程项目(TSQN202211115)。
关键词
单晶高温合金
显微组织
拉伸性能
断口形貌
位错
single crystal superalloy
microstructure
tensile property
fracture morphology
dislocation
