title: Dislocation network with pair-coupling structure in {111} γ/γ' interface of Ni-based single crystal superalloy.
abstract: The γ/γ' interface dislocation network is reported to improve the high temperature creep resistance of single crystal superalloys and is usually found to deposit in {001} interface. In this work, a new type of dislocation network was found in {111} γ/γ' interface at a single crystal model superalloy crept at 1100 °C/100 MPa. The dislocations in the network are screw with Burgers vectors of 1/2 a<110> and most interestingly, they exhibit a pair-coupling structure. Further investigation indicates that the formation of {111} interface dislocation network occurs when the γ' raft structure begins to degrade by the dislocations cutting into the rafted γ' through the interface. In this condition, the pair-coupling structure is established by the dislocations gliding in a single {111} plane of γ', in order to remove the anti-phase boundary in γ'; these dislocations also act as diffusion channels for dissolving of the γ' particle that is unstable under the interfacial stress from lattice misfit, which leads to the formation of {111}-type zigzag interface. The formation of this network arises as a consequence of more negative misfit, low-alloying γ' particle and proper test conditions of temperature and stress.
authors: School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, PR China.
authors: Yi
authors: Y
authors: Ru
authors: School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, PR China.
authors: Shusuo
authors: S
authors: Li
authors: School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, PR China.
authors: Jian
authors: J
authors: Zhou
authors: School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, PR China.
authors: Yanling
authors: Y
authors: Pei
authors: School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, PR China.
authors: Hui
authors: H
authors: Wang
authors: School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, PR China.
authors: Shengkai
authors: S
authors: Gong
authors: School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, PR China.
authors: Huibin
authors: H
authors: Xu