Browsing NTNU Open by Author "Zhao, Dongdong"
Now showing items 1-17 of 17
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A Thermodynamic Study on the Effect of Solute on the Nucleation Driving Force, Solid?Liquid Interfacial Energy, and Grain Refinement of Al Alloys
Xu, Yijiang; Zhao, Dongdong; Li, Yanjun (Journal article, 2018)Chemical composition is known to have significant effects on the grain refinement behavior of inoculated Al alloys during solidification. In this study, the influences of solute contents on the thermodynamic nucleation ... -
Carbon segregation at Σ3 {112} grain boundaries in silicon
Zhao, Dongdong; Li, Yanjun (Journal article; Peer reviewed, 2018)First-principles calculations were carried out to systematically investigate the carbon segregation along Σ3 {1 1 2} grain boundaries (GBs) in silicon. The energetically favorable segregation sites and corresponding ... -
Combined effect of Mg and vacancy on the generalized planar fault energy of Al
Zhao, Dongdong; Løvvik, Ole Martin; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2017)By first-principles calculations, a systematic study has been undertaken to investigate the combined effect of vacancies and Mg impurities on the generalized planar fault energy (GPFE) of pure Al. It was predicted that ... -
Enhanced nucleation and precipitation hardening in Al-Mg-Si(-Cu) alloys with minor Cd additions
Qian, Feng; Zhao, Dongdong; Mørtsell, Eva Anne; Jin, Shenbao; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Sha, Gang; Li, Yanjun (Peer reviewed; Journal article, 2020)This work reports a novel effect of impurity element Cd on enhancing the precipitation kinetics and increasing the peak hardness of Al–Mg–Si(–Cu) alloys during artificial ageing. It is found that the number density of age ... -
First-principles interpretation toward the effects of Cu, Mg co-segregation on the strength of Al Σ5 (210) grain boundary
Ma, Ning; Yu, Xuehao; Liu, Enzuo; Zhao, Dongdong; Sha, Junwei; He, Chunnian; Li, Yanjun; Zhao, Naiqin (Peer reviewed; Journal article, 2024)The co-segregation of Cu and Mg solutes at grain boundaries (GBs) in Al alloys is widely observed in experiments, but this segregation pattern is much less understood. Herein, the Cu, Mg co-segregation behaviors and their ... -
Grain boundary segregation in Pd-Cu-Ag alloys for high permeability hydrogen separation membranes
Løvvik, Ole Martin; Zhao, Dongdong; Li, Yanjun; Bredesen, Rune; Peters, Thijs (Journal article; Peer reviewed, 2018)Dense metal membranes that are based on palladium (Pd) are promising for hydrogen separation and production due to their high selectivity and permeability. Optimization of alloy composition has normally focused on bulk ... -
Impurity effect of Mg on the generalized planar fault energy of Al
Zhao, Dongdong; Løvvik, Ole Martin; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2016)Generalized planar fault energy (GPFE) curves are widely used to evaluate the deformation behavior of metals and alloys. In the present work, a systematic analysis of the microscopic plastic deformation mechanism of ... -
Impurity segregation at defects in Al and Si -A theoretical DFT based study
Zhao, Dongdong (Doctoral theses at NTNU;2017:273, Doctoral thesis, 2017)Alien impurity elements favor to stay at the defects, e.g. stacking fault, grain boundary (GB) in host materials and thus influence many material properties. On basis of atomistic simulations, the present thesis puts a ... -
Lattice distortion induced site dependent carbon gettering at twin boundaries in silicon
Zhao, Dongdong; Li, Yanjun (Journal article; Peer reviewed, 2017)The interactions between substitutional carbon atoms and S3 {111}, S9 {221}, and S27 {552} twin boundaries (TB) in silicon were investigated by first-principles calculations. The preferential segregation sites and segregation ... -
Modelling the Age-Hardening Precipitation by a Revised Langer and Schwartz Approach with Log-Normal Size Distribution
Zhao, Dongdong; Xu, Yijiang; Gouttebroze, Sylvain; Friis, Jesper; Li, Yanjun (Peer reviewed; Journal article, 2020)A new numerical modelling approach integrating the Langer and Schwartz approach and log-normal particle size distribution has been developed to depict the precipitation kinetics of age-hardening precipitates in Al alloys. ... -
Modelling the Spatial Evolution of Excess Vacancies and its Influence on Age Hardening Behaviors in Multicomponent Aluminium Alloys
Wang, Xuezhou; Zhao, Dongdong; Xu, Yijiang; Li, Yanjun (Peer reviewed; Journal article, 2023)Excess vacancies play crucial roles in the precipitation of age-hardening precipitates in aluminium alloys, but their spatial evolution across grains during heat treatments is less known. In this work, a numerical model ... -
Revealing the factors influencing grain boundary segregation of P, As in Si: Insights from first-principles
Zhao, Dongdong; Li, Yanjun (Journal article; Peer reviewed, 2019)Phosphorous (P) and arsenic (As) segregation at grain boundaries (GBs) usually deteriorate the electrical performance of n-type doped Si-wafers. In order to probe the factors influencing P and As segregation behaviors along ... -
Segregation of Mg, Cu and their effects on the strength of Al S5 (210) [001] symmetrical tilt grain boundary
Zhao, Dongdong; Løvvik, Ole Martin; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2018)Alien elemental segregation can pronouncedly change the grain boundary properties. Systematic first-principles calculations were performed to investigate the Mg and Cu segregation behavior at Σ5 (210)[001] symmetrical tilt ... -
Thermodynamic assessment of the Mo-S system and its application in thermal decomposition of MoS2
Cui, Senlin; Hu, Biao; Ouyang, Bin; Zhao, Dongdong (Journal article, 2018)The Mo-S system is crucial to extractive metallurgy, tribology, and various possible applications in design and fabrication of novel two-dimensional (2D) materials. First-principles calculations were utilized to compute ... -
Twinnability of Al–Mg alloys: A first-principles interpretation
Zhao, Dongdong; Løvvik, Ole Martin; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2017)Al–Mg alloys are considered to have potentials to form twins during deformation because Mg can reduce the intrinsic stacking fault energy γISFE of Al. Nevertheless, twinning has rarely been found in Al–Mg alloys even ... -
Unraveling the enhanced stability and strength of Al Σ9 (221)[ 1 1 ¯ 0 ] symmetric tilt grain boundary with Mg segregation
Ma, Ning; Zhao, Dongdong; Shi, Chunsheng; He, Chunnian; Liu, Enzuo; Sha, Junwei; Li, Yanjun; Zhao, Naiqin (Journal article; Peer reviewed, 2022) -
α-Mg primary phase formation and dendritic morphology transition in solidification of a Mg-Nd-Gd-Zn-Zr casting alloy
Casari, Daniele; Mirihanage, Wajira; Falch, Ken Vidar; Ringdalen, Inga Gudem; Friis, Jesper; Schmid-Fetzer, Rainer; Zhao, Dongdong; Li, Yanjun; Sillekens, Wim H.; Mathiesen, Ragnvald (Journal article; Peer reviewed, 2016)Microstructure evolution in the commercial Mg-Nd-Gd-Zn-Zr alloy Elektron 21, solidified under nearly isothermal conditions, has been studied via in-situ X-ray radiography. For cooling rates View the MathML source≤0.075 ...