Browsing NTNU Open by Author "Wan, Di"
Now showing items 1-19 of 19
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Additive manufacturing of fine-grained and dislocation-populated CrMnFeCoNi high entropy alloy by laser engineered net shaping
Guan, Shuai; Wan, Di; Solberg, Klas; Berto, Filippo; Welo, Torgeir; Yue, Tai Man; Chan, K.C. (Journal article; Peer reviewed, 2019)The equiatomic CrMnFeCoNi high entropy alloy is additively manufactured by the laser engineered net shaping (LENSTM) process, and the solidification conditions, phase formation, as-deposited microstructures, and tensile ... -
Assessment of the potential of hydrogen plasma charging as compared to conventional electrochemical hydrogen charging on dual phase steel.
Depover, Tom; Hajilou, Tarlan; Wan, Di; Wang, Dong; Barnoush, Afrooz; Verbeken, Kim (Journal article; Peer reviewed, 2019)The present study evaluates the hydrogen induced damage by in-situ hydrogen plasma charging in dual phase (DP) steel. Cold deformation of 15% is applied on the material to change microstructural defects, such as dislocation ... -
Effect of electrochemical charging on the hydrogen embrittlement susceptibility of Alloy 718
Lu, Xu; Wang, Dong; Wan, Di; Zhang, Zhenbo; Kheradmand, Nousha; Barnoush, Afrooz (Peer reviewed; Journal article, 2019)The susceptibility of age-hardened nickel-based Alloy 718 to hydrogen embrittlement was studied by the controlled electrochemical charging combined with slow strain-rate tensile tests (SSRT) and advanced characterization ... -
Effect of hydrogen-induced surface steps on the nanomechanical behavior of a CoCrFeMnNi high-entropy alloy revealed by in-situ electrochemical nanoindentation
Wang, Dong; Lu, Xu; Deng, Yun; Wan, Di; Li, Zhiming; Barnoush, Afrooz (Peer reviewed; Journal article, 2019)The effect of hydrogen on the nanomechanical properties of CoCrFeMnNi high-entropy alloy was investigated by in-situ electrochemical nanoindentation testing. The changes in surface morphology, elastic modulus, pop-in load, ... -
Formation of fully equiaxed grain microstructure in additively manufactured AlCoCrFeNiTi0.5 high entropy alloy
Guan, Shuai; Solberg, Klas; Wan, Di; Berto, Filippo; Welo, Torgeir; YUE, TM; Chan, KC (Journal article; Peer reviewed, 2019)In this work, the non-equiatomic high entropy alloy AlCoCrFeNiTi0.5 was additively manufactured via the laser engineered net shaping (LENS™) process. Contrary to the columnar grain microstructure commonly observed in ... -
Hydrogen embrittlement effect observed by in-situ hydrogen plasma charging on a ferritic alloy
Wan, Di; Deng, Yun; Barnoush, Afrooz (Journal article; Peer reviewed, 2018)To study the hydrogen embrittlement (HE) effect, a novel in-situ slow strain rate tensile test together with in-situ hydrogen (H) charging by H-plasma was conducted in an environmental scanning electron microscope (ESEM). ... -
Hydrogen Enhanced Fatigue Crack Growth Rates in a Ferritic Fe-3wt%Si Alloy
Alvaro, Antonio; Wan, Di; Olden, Vigdis; Barnoush, Afrooz (Journal article; Peer reviewed, 2018)It is well known that the presence of hydrogen in ferrous materials promotes both static fracture and affect the material fatigue crack growth rates. The latter is often referred to as Hydrogen Enhanced Fatigue Crack Growth ... -
Hydrogen enhanced fatigue crack growth rates in a ferritic Fe-3 wt%Si alloy and a X70 pipeline steel
Alvaro, Antonio; Wan, Di; Olden, Vigdis; Barnoush, Afrooz (Journal article; Peer reviewed, 2019)It is well known that ferrous materials can be damaged by absorption of hydrogen. If a sufficient quantity of hydrogen penetrates into the material, static fracture and the material's fatigue performances can be affected ... -
Hydrogen-Assisted Fatigue Crack Growth in Ferritic Steels
Wan, Di (Doctoral theses at NTNU;2019:251, Doctoral thesis, 2019) -
Hydrogen-assisted fatigue crack growth in ferritic steels – a fractographic study
Wan, Di; Alvaro, Antonio; Olden, Vigdis; Barnoush, Afrooz (Journal article; Peer reviewed, 2018)Fatigue crack growth (FCG) behavior of a Fe-3wt.%Si ferritic alloy under different environmental conditions using in-situ electrochemical (cathodic) hydrogen (H) charging has been investigated. Three frequencies have been ... -
Hydrogen-enhanced fatigue crack growth behaviors in a ferritic Fe-3wt%Si steel studied by fractography and dislocation structure analysis
Wan, Di; Alvaro, Antonio; Olden, Vigdis; Barnoush, Afrooz (Journal article; Peer reviewed, 2019)The effect of hydrogen (H) on the fatigue behavior is of significant importance for metallic structures. In this study, the hydrogen-enhanced fatigue crack growth rate (FCGR) tests on in-situ electrochemically H-charged ... -
Hydrogen-enhanced fatigue crack growth in a single-edge notched tensile specimen under in-situ hydrogen charging inside an environmental scanning electron microscope
Wan, Di; Deng, Yun; Meling, Jan Inge Hammer; Alvaro, Antonio; Barnoush, Afrooz (Journal article; Peer reviewed, 2019)Fatigue crack growth (FCG) test was done on a pre-cracked single-edge notched tensile (SENT) specimen with oligocrystalline ferritic structure. Innovative in-situ hydrogen (H)- charging by plasma inside an environmental ... -
In-situ micro-cantilever bending test in environmental scanning electron microscope: Real time observation of hydrogen enhanced cracking
Deng, Yun; Hajilou, Tarlan; Wan, Di; Kheradmand, Nousha; Barnoush, Afrooz (Journal article, 2017)A novel approach of in-situ micro-cantilever bending tests is introduced, integrating nanoindentation and environmental scanning electron microscopy (ESEM) to elucidate hydrogen embrittlement (HE) in FeAl. Bending tests ... -
In-situ observation of martensitic transformation in an interstitial metastable high-entropy alloy during cathodic hydrogen charging
Wang, Dong; Lu, Xu; Wan, Di; Li, Zhiming; Barnoush, Afrooz (Journal article; Peer reviewed, 2019)We show for the first time that a critical amount of dissolved hydrogen can induce a phase transformation from γ-austenite to ε-martensite in an interstitial metastable high-entropy alloy. This is demonstrated by in-situ ... -
Novel in-situ residual strain measurements in additive manufacturing specimens by using the Optical Backscatter Reflectometry
Wang, Shaoquan; Lasn, Kaspar; Elverum, Christer Westum; Wan, Di; Echtermeyer, Andreas (Journal article; Peer reviewed, 2020)Material extrusion (MEX) is a well established production method in additive manufacturing. However, internal residual strains are accumulated during the layer-by-layer fabrication process. They bring about shape distortions ... -
Plasticity in cryogenic brittle fracture of ferritic steels: Dislocation versus twinning
Wan, Di; Barnoush, Afrooz (Journal article; Peer reviewed, 2019)The sub-surface deformation structure after cryogenic (77 K) brittle fracture in a ferritic steel was characterized by scanning electron microscopy (SEM). Twin-like structures were found in many grains below the fracture ... -
Strain visualization of growing short fatigue cracks in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint: Intergranular cracking and crack closure
Liu, Shi-Dong; Zhu, Ming-Liang; Zhou, Hai-Bo; Wan, Di; Xuan, Fu-Zhen (Peer reviewed; Journal article, 2019)Physically short fatigue crack growth behavior in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint was investigated in-situ in SEM to reveal effects of crack closure and tortuous crack growth path on crack-tip ... -
Super long-range diffusion of carbon during proeutectoid ferrite transformation
Zhang, Suoquan; Jiao, Sihai; Ding, Jianhua; Wan, Di; Liu, Zhenyu; Wang, Guodong (Journal article; Peer reviewed, 2019)In order to explore the possible diffusion distance of carbon during proeutectoid ferrite transformation, a slow cooling test of low carbon steel was carried out under vacuum of the thermal simulator. The microstructure ... -
The influence of hydrogen on cyclic plasticity of <001> oriented nickel single crystal. Part I: dislocation organisations and internal stresses
Hachet, G; Oudriss, A; Barnoush, Afrooz; Milet, R; Wan, Di; Metsue, A; Feaugas, X (Journal article; Peer reviewed, 2019)The present paper discussed the impact of hydrogen on the mechanical response of cyclically strained nickel single crystal oriented for multi-slips at different length scales. At macroscale, as a function of the plastic ...