Effects of Dendritic Orientation on Stress Rupture Properties of DD6 Single Crystal Superalloy

作     者：SHI Zhen-xue LI Jia-rong LIU Shi-zhong ZHAOJin-qian 

作者机构：National Key Laboratory of Science and Technology on Advanced High Temperature Structural Materials Beijing Institute of Aeronautical Materials Beijing 100095 China 

出 版 物：《Journal of Iron and Steel Research(International)》 (钢铁研究学报（英文版）)

年 卷 期：2011年第18卷第10期

页      面：66-71页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

主　　题：DD6 single crystal superalloy stress rupture property fracture behaviour 

摘      要：DD6 single crystal superalloy slabs were prepared with seed method in the direetionally solidified furnace with high temperature gradient. The transverse stress rupture properties and fracture hehaviour of the alloy at 760 ℃/758 MPa, 850 ℃/550 MPa and 980 ℃/250 MPa were investigated and compared with those of longitudinal specimens. The transverse stress rupture lives are corresponding with the longitudinal stress rupture lives at 760 ℃/758 MPa and 850 ℃/550 MPa. The transverse stress rupture lives are slightly less than the longitudinal stress rupture lives at 980 ℃/ 250 MPa. The fracture mechanism of the transverse stress rupture of the alloy at 760 ℃/758 MPa shows quasi-cleav- age mode and the fracture mechanism at 980 ℃/250 MPa shows dimple mode, while the fracture mechanism at 850 ℃/ 550 MPa shows quasi-cleavage and dimple mixture mode. At higher temperature and lower stress, the microeracks are easier to initiate and interconnect in the transverse specimen than those in longitudinal specimen because there are interdendritic regions perpendicular to the axis of stress.