Browsing NTNU Open by Author "Li, Yanjun"
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A TEM Study of Weakly Overaged Precipitates in AA 6082
Sulen, Olav (Master thesis, 2016)New models for modeling the material properties for aluminium alloys that can take into consideration the geometry of the needle shaped precipitates, that can be found in 6xxx alloys are being developed. The background for ... -
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 ... -
Accelerated recrystallization by electric current flash heating in cold-rolled Al-5Cu alloy under the influence of concurrent precipitation
Wang, Shubo; Jia, Hailong; Li, Yanjun (Journal article; Peer reviewed, 2019)The influence of flash heating by using a continuous direct current on the recrystallization behavior of an Al-5Cu alloy under the influence of concurrent precipitation of Al2Cu precipitates has been investigated. In ... -
Achieving dispersed fine soft Bi particles and grain refinement in a hypermonotectic Al-Bi alloy by severe plastic deformation and annealing
Zha, Min; Yu, Zhiyuan; Qian, Feng; Wang, Huiyuan; Li, Yanjun; Mathiesen, Ragnvald; Roven, Hans Jørgen (Journal article; Peer reviewed, 2018)The present work revealed that equal-channel angular pressing (ECAP) deformation combined with appropriate annealing could represent as an efficient route to modify immiscible as-cast microstructure of a monotectic Al–8Bi ... -
Al-5Cu alloy processed by equal-channel angular pressing
Jia, Hailong; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2017)An ECAP (equal channel angular pressing) processed UFG Al-5Cu alloy was characterized by electron backscatter diffraction (EBSD). It is revealed that a bimodal grain structure, i.e. ultrafine grains accompanied by micron-sized ... -
AlSi10Mg alloy nanocomposites reinforced with aluminum-coated graphene: Selective laser melting, interfacial microstructure and property analysis
Zhao, Zhanyong; Bai, Peikang; Misra, RDK; Dong, Mengyao; Guan, Renguo; Li, Yanjun; Zhang, Jiaoxia; Tan, Le; Gao, Jianfeng; Ding, Tao; Du, Wenbo; Guo, Zhanhu (Journal article; Peer reviewed, 2019)Graphene has been successfully coated with a nano-Al layer through a novel activating treatment (i.e., organic aluminum reduction method). The nano-Al coated graphene was further processed into AlSi10Mg alloy based composites ... -
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 (Journal article; Peer reviewed, 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 ... -
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 ... -
Characterization of Iron Bearing Particles in Relation to Fir-Tree Structure in Al-Mg Alloys
Solli, Idun (Master thesis, 2018)Fir-tree structure is a well-known problem related to DC cast AA1xxx and AA5xxx alloys. During DC casting different iron bearing particles, e.g. AlmFe, Al3Fe and Al6Fe, are formed. A change of the dominating iron bearing ... -
Characterization the softening behavior of cold rolled AlMnFeSi-alloys during conditions of concurrent precipitation
Wang, Ning; Li, Yanjun; Marthinsen, Knut (Journal article, 2013)In the present work an Al-Mn-(Fe-Si) model alloy has been subjected to different homogenization treatments, to achieve materials with different microchemistry states in terms of constituents, levels of Mn in solid solution ... -
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 ... -
Cu Interlayer-Induced High-Strength Laser-Welded AISI 304 Steel-Niobium Joint
Shi, Mingxiao; Li, Yanjun; Ma, Xiang (Peer reviewed; Journal article, 2019)Joining niobium to austenitic stainless steel is necessary for the fabrication of particle accelerators. However, the brittle iron-niobium intermetallics formed in the joint significantly reduce the joint strength. Copper ... -
Deformation of an Al-7Mg alloy with extensive structural micro-segregations during dynamic plastic deformation
Jin, Shenbao; Tao, Nairong; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2015)The microstructure evolution and deformation behavior of an as-cast Al–7Mg alloy with severe Mg segregation zones distributed on grain boundaries and in interdendrite regions subjected to dynamic plastic deformation (DPD) ... -
Effect of Ag addition on the precipitation evolution and interfacial segregation for Al?Mg?Si alloy
Weng, Yaoyao; Ding, Lipeng; Zhang, Zezhong; Jia, Zhihong; Wen, Boyang; Liu, Yingying; Muraishi, Shinji; Li, Yanjun; Liu, Qing (Journal article; Peer reviewed, 2019)The effect of Ag addition on the precipitation evolution and interfacial segregation for Al–Mg–Si alloys was systematically investigated by atomic resolution high-angle annular dark-field scanning transmission electron ... -
Effect of Mn and cooling rates on α-, β- and δ-Al–Fe–Si intermetallic phase formation in a secondary Al–Si alloy
Becker, Hanka; Bergh, Tina; Vullum, Per Erik; Leineweber, Andreas; Li, Yanjun (Journal article; Peer reviewed, 2019)Secondary Al–Si alloys Al7.1Si(1.5-xMn)Fe(xMn)Mn with xMn = 0, 0.3, 0.375, 0.6, 0.75 at.% have been solidified with different cooling rates: 0.05 K/s, 1.4 K/s, 11.4 K/s and 200 K/s. In the ternary alloy with xMn = 0 at.%, ... -
Effect of soft Bi particles on grain refinement during severe plastic deformation
Jia, Hailong; Marthinsen, Knut; Li, Yanjun (Journal article; Peer reviewed, 2017)Two aluminum alloys, Al–8Zn and Al–6Bi–8Zn were subjected to equal channel angular pressing (ECAP) up to 5 passes at room temperature. The microstructural evolution and the grain refinement behavior of these alloys were ... -
Effect of Surface Treatment and Preheating Temperature on Compound Casting of Aluminium Alloy A356 onto 6060 Inserts
Grasmo, Siren (Master thesis, 2019)For bilindustrien er det viktig å studere ulike metoder for å redusere kjøretøyvekt, da dette reduserer bensinforbruk, noe som vil ha både økonomiske og miljømessige fordeler. Hybridstøpning er å støpe et flytende materiale ... -
Effects of Surface Treatment on Hypoeutectoid Steels and Commercially Pure Copper in a Compound Casting Process with Aluminum A356 Alloy
Bakke, Aina Opsal (Master thesis, 2017)Evidence of climate change has caused industries worldwide to start measures towards reducing greenhouse gas emission. The automotive industry is a large contributor to emission and has therefore demanded production of ... -
Engineering grain boundary structures of aluminium alloys and titanium by high strain/ strain rate deformation
Jia, Hailong (Doctoral theses at NTNU;2018:139, Doctoral thesis, 2018)A comprehensive study was carried out to clarify the effects of severe plastic deformation (SPD) and high strain rate deformation on various aluminium alloys and commercial purity titanium. Equal channel angular pressing ... -
Enhanced dispersoid precipitation and dispersion strengthening in an Al alloy by microalloying with Cd
Qian, Feng; Jin, Shenbao; Sha, Gang; Li, Yanjun (Journal article; Peer reviewed, 2018)The dispersion hardening effect of Mn(Fe)-containing dispersoids in aluminium alloys has long been ignored since it is difficult to achieve a high number density of fine dispersoids with conventional alloying compositions. ...