Browsing SINTEF Open by Author "Li, Yanjun"
Now showing items 1-20 of 23
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Atomistic approach to simulate kink migration and kink-pair formation in silicon: The kinetic activation-relaxation technique
Eliassen, Simen Nut Hansen; Friis, Jesper; Ringdalen, Inga Gudem; Mousseau, Normand; Trochet, Mickaël; Li, Yanjun (Peer reviewed; Journal article, 2019)The energy conversion efficiency of solar cells based on multicrystalline silicon is greatly deteriorated by dislocations. However, an in-depth understanding on the dislocation motion dynamics down to atomic scale is still ... -
The Effect of Grain Refiner on Aluminium Filtration
Bao, Sarina; Yang, Jiawei; Akhtar, Shahid; Tundal, Ulf; Tjøtta, Stig; Pettersen, Tanja; Li, Yanjun (The Minerals, Metals & Materials Series;2367-1181, Peer reviewed; Journal article, 2021)Grain refinement of aluminium and its alloys is a common industrial practice. Fine equiaxed, grain structure leads to improved castability, strength, machinability, formability, and good surface finish. Filtration is one ... -
Effect of heat input on nanomechanical properties of wire-arc additive manufactured Al 4047 alloys
Liu, Siqi; Wan, Di; Peng, Ding; Lu, Xu; Ren, Xiaobo; Fu, Yuequn; Wang, Feng; Li, Yanjun; Zhang, Zhiliang; He, Jianying (Peer reviewed; Journal article, 2022)Heat input is one of the most important process parameters during additive manufacturing (AM). It is of great significance to understand the effect of heat input on the microstructure and nanomechanical properties, as well ... -
Effect of Inclusion and Filtration on Grain Refinement Efficiency of Aluminum Alloy
Yang, Jiawei; Xu, Yijiang; Bao, Sarina; Akhtar, Shahid; Tundal, Ulf; Tjøtta, Stig; Li, Yanjun (Peer reviewed; Journal article, 2022)It is well known that the filtration efficiency of ceramic foam filters (CFF) on aluminum melt can be significantly reduced by the addition of grain refiner particles under a high inclusion load. Also, it is usually ... -
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 ... -
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 (Peer reviewed; Journal article, 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 ... -
Heterogeneous nucleation and grain growth of inoculated aluminium alloys: An integrated study by in-situ X-radiography and numerical modelling
Xu, Yijiang; Casari, Daniele; Du, Qiang; Mathiesen, Ragnvald; Arnberg, Lars; Li, Yanjun (Peer reviewed; Journal article, 2017)A comprehensive study on the heterogeneous nucleation and grain growth of Al-10 wt.%Cu alloys inoculated with Al-5Ti-1B was carried out. To further reveal the solute segregation stifling mechanism, in-situ near-isothermal ... -
Improving ageing kinetics and precipitation hardening in an Al-Mg-Si alloy by minor Cd addition
Qian, Feng; Mørtsell, Eva Anne; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Li, Yanjun (Peer reviewed; Journal article, 2018)This study reports significant improvements in both the age hardening kinetics and peak hardness of an Al-Mg-Si alloy by microalloying with 0.06 at% Cd. A detailed high-angle annular dark-field scanning transmission electron ... -
Influence of dispersoids on microstructure evolution and work hardening of aluminium alloys during tension and cold rolling
Zhao, Qinglong; Holmedal, Bjørn; Li, Yanjun (Peer reviewed; Journal article, 2013)The influence of dispersoids on work hardening of aluminium during tension and cold rolling has been studied by comparing Al–Mn alloys containing similar amounts of solutes but various dispersoid densities. The microstructure ... -
Influence of grain refiners on the wettability of Al2O3 substrate by aluminum melt
Yang, Jiawei; Bao, Sarina; Akhtar, Shahid; Shen, Ping; Li, Yanjun (Peer reviewed; Journal article, 2020)It is well known that grain refiner additions in aluminum melts significantly reduce the filtration efficiency of ceramic foam filters (CFF). However, the mechanism remains unclear. In this work, the influence of grain ... -
Influence of natural aging and ramping before artificial aging on the microstructure of two different 6xxx alloys
Hell, Christoph Martin; Søreide, Hanne-Sofie Marie Scisly; Bjørge, Ruben; Marioara, Calin Daniel; Li, Yanjun; Holmestad, Randi (Peer reviewed; Journal article, 2022)In this study the effect of a ramp up to artificial aging (AA) temperature in combination with natural aging (NA) was analyzed for two different industrial aluminium alloys. The alloys differ in their Mg/Si ratio as well ... -
The Influences of Grain Refiner, Inclusion Level, and Filter Grade on the Filtration Performance of Aluminum Melt
Yang, Jiawei; Bao, Sarina; Akhtar, Shahid; Tundal, Ulf; Tjøtta, Stig; Li, Yanjun (Peer reviewed; Journal article, 2021)The addition of grain refiner particles in the aluminum melt is known to reduce the filtration efficiency of ceramic foam filter (CFF). In the present work, a systematic study on the influence of the addition level of ... -
The Interactions Between Oxide Film Inclusions and Inoculation Particles TiB2 in Aluminum Melt
Yang, Jiawei; Bao, Sarina; Akhtar, Shahid; Li, Yanjun (Peer reviewed; Journal article, 2021)In this work, a systematic study on the interactions between aluminum oxide films and TiB2 grain refiner particles and their effect on grain refinement behavior have been conducted. Oxide f ilms were introduced into a ... -
Interfacial microstructure formation in A356/steel compound castings using metal coating
Bakke, Aina Opsal; Nordmark, Arne; Arnberg, Lars; Li, Yanjun (Peer reviewed; Journal article, 2020)Compound castings between aluminum and steel have great potential for applications in the automotive industry. However, due to large differences in thermal and mechanical properties between steel and aluminum, and the ... -
Isothermal annealing of cold-rolled Al−Mn−Fe−Si alloy with different microchemistry states
Huang, Ke; Li, Yanjun; Marthinsen, Knut (Peer reviewed; Journal article, 2014)Microstructural evolution of a cold-rolled Al–Mn–Fe–Si alloy during annealing was studied. Except the as-cast variant, two other different homogenizations were considered, one gave a high density of fine dispersiods providing ... -
Laser welding of niobium to AISI 304 steel using a copper interlayer
Zhao, Jian; Shi, Mingxiao; Li, Yanjun; Ma, Xiang; Fang, Zhenxing; Yan, Hua (Peer reviewed; Journal article, 2020)Cu interlayers with thicknesses of 1, 1.5, and 2 mm were used to join niobium and AISI 304 steel. Fractures occurred in the weld, the Nb base metal, and the unmelted Cu interlayer when the Cu interlayer thickness was 1, ... -
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. ... -
Precipitation in an A356 foundry alloy with Cu additions - A transmission electron microscopy study
Mørtsell, Eva Anne; Qian, Feng; Marioara, Calin Daniel; Li, Yanjun (Peer reviewed; Journal article, 2019)The influence of different Cu addition levels on the age hardening and precipitation behaviors in an Al356 foundry alloy during artificial aging treatment has been systematically studied. A detailed characterization of the ... -
Prediction of solute diffusivity in Al assisted by first-principles molecular dynamics
Løvvik, Ole Martin; Sagvolden, Espen; Li, Yanjun (Peer reviewed; Journal article, 2014)Ab initio calculations of the solid-state diffusivity of solute atoms in bulk aluminium have previously been based on transition state theory (TST), employing transition state searches and systematic assessments of single ... -
Quantifying the grain boundary segregation strengthening induced by post-ECAP aging in an Al-5Cu alloy
Jia, Hailong; Bjørge, Ruben; Cao, Lingfei; Hui, Song; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2018)Hardening on annealing (HOA) has been frequently observed in nanostructured metals and alloys. For nanostructured materials obtained by severe plastic deformation (SPD), HOA has been attributed to the reduction of dislocation ...