Article
Nanoscience & Nanotechnology
Yawei Li, Li Wang, Yufeng He, Wei Zheng, Langhong Lou, Jian Zhang
Summary: The study found that as the temperature increases, the spacing of dislocation networks in the gamma/gamma' interface decreases, while the minimum creep rate increases non-linearly. This is due to the enhanced dislocation-climb in the interface and gamma'-cutting by a <010> superdislocations.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Peng Zhang, Linfu Zhang, Qiang Zhu, Gang Chen, Chuanjie Wang, Guohua Fan, Heyong Qin
Summary: The evolution models of interfacial dislocation and yield mechanism play a critical role in the mechanical properties of nickel-based single crystal superalloy. Through molecular dynamics methods, the deformation process of the alloy was investigated, revealing the formation of a special cone-like microstructural defect under uniaxial compressive loading. This unique structure significantly improved the yield strength by hindering the slipping of dislocations. The yield mechanism was explained as the decomposition of sessile dislocations and the shearing of the gamma' phase under compressive loading.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Yuxi Gao, Jinwen Zou, Huaming Wang, Yongquan Han
Summary: This study investigates the fabrication of graphene nanosheet (GNS) reinforced nickel based superalloy (FGH96) composites and the effect of interfacial reaction products between GNS and FGH96 matrix on the interface structure. The results show that the in-situ reaction between GNS and FGH96 matrix leads to the formation of [Ti, Nb]C particles, which significantly enhances the interfacial strength and mechanical transfer efficiency. The role of these particles in determining the interfacial bonding strength and mode is discussed.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Alexander Bergsmo, Yilun Xu, Benjamin Poole, Fionn P. E. Dunne
Summary: The study found that non-metallic inclusions and twin boundaries are preferred locations for fatigue crack nucleation in polycrystalline Ni-based superalloys. Through a multi-scale modelling strategy, the mechanism of fatigue crack nucleation was analyzed, revealing the involvement of inclusion fracture, twin boundary slip activation, and the accumulation of local geometrically necessary dislocations. These factors ultimately lead to the formation of fatigue cracks.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Chemistry, Physical
Sagar Chandra, Alankar Alankar, Mahendra K. Samal, Vivek M. Chavan
Summary: Understanding the plastic deformation and failure mechanisms in Ni-based superalloys is crucial for improving their intrinsic ductility. In this study, atomistic simulations are used to illustrate the complex deformation mechanisms during tensile deformation of pre-cracked Ni-Ni3Al single crystals. The competition between dislocation emission and cleavage is evaluated under various pre-cracked configurations, and the results reveal the dependence on crystallographic orientation. The computed crack propagation toughness is in good agreement with experimental data. The variations in overall toughness are discussed in relation to the observed deformation landscapes.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Guangyan Wang, Song Zhang, Sugui Tian, Ning Tian, Guoqi Zhao, Huajin Yan
Summary: This study investigates the microstructure evolution and deformation mechanism of a [111]-oriented nickel-based single-crystal superalloy at 980 degrees C/186 MPa through creep measurement and microstructure observation. The results reveal that the material undergoes phase transformation and dislocation slip during creep, leading to creep fracture.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Fei Sui, Teng An, Shuqi Zheng, Liqiang Chen, Shuyin Li
Summary: The influence of effective strains on the corrosion behavior of GH4710 superalloy in chloride solutions was studied, and the corrosion resistance was explained by analyzing the microstructure and grain boundary properties.
Article
Materials Science, Multidisciplinary
Luca Reali, Daniel S. Balint, Mark R. Wenman
Summary: Discrete dislocation plasticity (DDP) simulations were conducted to investigate the influence of Zr micro-hydrides on dislocation density, plastic deformation, and stress. The results revealed that even thin hydrides with a thickness of 20 nm had a significant impact on these properties, and the effect increased with increasing hydride thickness. The study also identified the Zr/hydride interface as the critical location for crack nucleation, where the formation of slip bands was accompanied by high stresses. The simulations represented hydrides solely through interfacial stress, without introducing point obstacles or changes in slip systems, providing a possible mechanistic explanation for embrittlement caused by intragranular hydride precipitation.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Tian Ning, Zhao Guoqi, Meng Tai, Tian Sugui, Liu Lirong, Yan Huajin, Wang Guangyan, Jin Fangwei
Summary: The nickel-based single-crystal superalloy containing 6% Re/5% Ru exhibited good creep resistance and smaller strain rate at 1170 degrees C/110 MPa. The resistance of dislocation movement in the matrix was increased by the higher content of refractory elements, resulting in more Kear-Wilsdorf (K-W) dislocation locks that enhanced the alloy resistance. The interactions of Ru with Re and W atoms delayed elemental diffusion and depressed dislocation movement, contributing to the retention of more K-W dislocation locks and good resistance during ultra-high-temperature creep.
MATERIALS CHARACTERIZATION
(2021)
Article
Engineering, Mechanical
Qingbing Dong, Zhuang Chen, Xueyu Bai, Jing Wei, Kun Zhou
Summary: This study developed a numerical model to investigate the fretting behavior of layered materials with mixed-mode I and II cracks at the layer/layer/substrate interfaces under plane-strain conditions.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Materials Science, Multidisciplinary
Ziang Chen, Yi Tan, Yi Li, Jiaqi Zhao, Shuang Song, Pengting Li
Summary: The sessile-drop method in vacuum environment was used to study the wettability and interfacial reaction between the DD5 superalloy melt and Al2O3-based ceramic shell. The results showed that the oxygen content in the superalloy affected the wetting angle and thickness of the interfacial reaction layer. The interfacial reaction products were mainly Al2O3, with Si element detected in a diffuse distribution.
Article
Materials Science, Characterization & Testing
J. J. Wang, Z. X. Wen, H. Q. Pei, C. J. Zhang, Y. M. Zhang, Z. F. Yue
Summary: This research focuses on Nickel-based single crystal (NBSX) superalloys and uses tensile interruption tests and linear and nonlinear ultrasonic nondestructive methods to evaluate plastic damage and study the plastic deformation mechanism at room temperature. The results show that the ultrasonic nonlinear parameter beta is highly sensitive to early tensile plastic damage and can accurately assess the extent of plastic damage. Observations under optical microscope and transmission electron microscope reveal that the plastic deformation mechanism involves anti-phase boundary dislocation pairs shear gamma' phase, and cumulative tensile plastic deformation leads to an increase in strength and a decrease in plasticity.
NDT & E INTERNATIONAL
(2022)
Article
Engineering, Aerospace
Haihang Wang, Jie Chen, Chenguang Wang, Guoqiang Guo, Qinglong An, Weiwei Ming, Ming Chen
Summary: Nickel-based Superalloy Honeycomb (NBSH) is prone to burr formation during processing, which can lead to insufficient welding strength or false welding, causing premature failure. The study investigates the burr formation mechanism and critical conditions in grinding NBSH using finite element method (FEM) and experiments. Orthogonal experiments were conducted to determine the suitable parameter intervals to restrain flash burr formation. The results show that the absence of supporting material leads to the formation of micro burrs, which can combine with chips to form flash burrs if the material removal per unit time is large. The suitable intervals of grinding depth, grinding speed and feed speed were identified to restrain flash burr formation.
CHINESE JOURNAL OF AERONAUTICS
(2023)
Article
Materials Science, Multidisciplinary
Tushar Jogi, Saswata Bhattacharya
Summary: Ni-base superalloys exhibit an intricate network of dislocations around gamma ' precipitates during high-temperature low-to-intermediate stress creep. Three-dimensional discrete dislocation dynamics simulations reveal the evolution of dislocation network on the surfaces of unsheared, cuboidal gamma ' precipitates. The study suggests that dislocation climb is the rate-controlling mechanism, with a constant mobile-to-immobile dislocation density ratio observed at steady state.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Manufacturing
Qing Miao, Wenfeng Ding, Jiuhua Xu, Lijie Cao, Hongcai Wang, Zhen Yin, Chenwei Dai, Weijie Kuang
Summary: The study investigated the surface deformation structures of turbine blade root of single crystal nickel-based superalloy produced under different creep feed grinding conditions, revealing gradient microstructures in the superficial layer. The formation of such gradient microstructures was found to be related to the graded variations in the plastic strain and strain rate induced in the creep feed grinding process.
INTERNATIONAL JOURNAL OF EXTREME MANUFACTURING
(2021)