Microstructure transformation and grain refinement during non-equilibrium solidification of a highly undercooled alloy system

2021 ◽  
Vol 864 ◽  
pp. 158821
Author(s):  
Yukang An ◽  
Xiaolong Xu ◽  
Lei Liang ◽  
Yuhong Zhao ◽  
Hua Hou
Keyword(s):  
Grain Refinement ◽  
Alloy System ◽  
Microstructure Transformation ◽  
Equilibrium Solidification ◽  
Non Equilibrium

Microstructure Evolution in Undercooled Ni-Si Melt

2013 ◽  
Vol 749 ◽  
pp. 349-355
Author(s):  
Kai Fan ◽  
Feng Liu ◽  
Bao Quan Fu ◽  
Wen Zhong Luo ◽  
Yao He Zhou
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Grain Refinement ◽  
Microstructure Evolution ◽  
Solid Solubility ◽  
Molten Glass ◽  
Dendrite Fragmentation ◽  
Equilibrium Solidification ◽  
Good Agreement ◽  
Non Equilibrium

Upon non-equilibrium solidification, the intrinsic parameters, such as moving velocity, temperature, solute partition coefficient, and liquid and solid concentrations at the interface, deviate from their equilibrium characteristics, and the morphology of the as-solidified structure and the grain size are influenced by the non-equilibrium liqulid/solid transformation, which further influences the subquent solidstate transformation. Adopting molten glass purification technology combined with cycle superheating method, the microstructure evolution of Ni-11at.%Si alloy in different undercooling was investigated. It was found that, with the increase of the initial undercooling, grain refinement occurred in microstructures of undercooled Ni-11at.%Si alloy. Meanwhile, the NL model was used to discuss the two different dendrite morphologies. According to Karmas model for dendrite fragmentation, the grain refinement of undercooled Ni-11at.%Si alloy was in good agreement with the experimental data, and the grain size was reduced with the increasing ΔT. The energy-dispersive spectroscopy (EDS) measurement was applied to analyze the solid solubility of Si atom in α-Ni matrix. It was found that the solid solubility of Si atom in α-Ni matrix increased with undercooling. At the undercooling of T>220K , a complete solute trapping occurred.

scholarly journals Grain Refinement by Second Phase Particles under Applied Stress in ZK60 Mg Alloy with Y through Phase Field Simulation

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1903 ◽  
Author(s):  
Yuhao Song ◽  
Mingtao Wang ◽  
Yaping Zong ◽  
Ri He ◽  
Jianfeng Jin
Keyword(s):  
Grain Refinement ◽  
Applied Stress ◽  
Phase Field ◽  
Phase Particle ◽  
Alloy System ◽  
Second Phase ◽  
Recrystallization Process ◽  
Time Space ◽  
Second Phase Particles ◽  
Zk60 Alloy

Based on the principle of grain refinement caused by the second-phase particles, a phase field model was built to describe the recrystallization process in the ZK60 alloy system with Y added under applied stress between temperatures 573 and 673 K for 140 min duration. The simulation of grain growth with second phase particles and applied stress during annealing process on industrial scale on the condition of real time-space was achieved. Quantitative analysis was carried out and some useful laws were revealed in ZK60 alloy system. The second phase particles had a promoting effect on the grain refinement, however the effect weakened significantly when the content exceeded 1.5%. Our simulation results reveal the existence of a critical range of second phase particle size of 0.3–0.4 μm, within which a microstructure of fine grains can be obtained. Applied stress increased the grain coarsening rate significantly when the stress was more than 135 MPa. The critical size of the second phase particles was 0.4–0.75 μm when the applied stress was 135 MPa. Finally, a microstructure with a grain size of 11.8–13.8 μm on average could be obtained when the second phase particles had a content of 1.5% and a size of 0.4–0.75 μm with an applied stress less than 135 Mpa after 30 min annealing at 573 K.

scholarly journals The development of non-equilibrium solidification theories

2015 ◽  
Vol 45 (4) ◽  
pp. 358-376 ◽  
Author(s):  
WangWang KUANG ◽  
HaiFeng WANG ◽  
Feng LIU ◽  
Kang WANG
Keyword(s):  
Equilibrium Solidification ◽  
Non Equilibrium

scholarly journals Back-Diffusion In Crystal Growth. Eutectics

2015 ◽  
Vol 60 (3) ◽  
pp. 2403-2407 ◽  
Author(s):  
W. Wołczyński
Keyword(s):  
Differential Equation ◽  
Crystal Growth ◽  
Current Model ◽  
Solute Segregation ◽  
Solidification Path ◽  
Back Diffusion ◽  
Eutectic Alloys ◽  
Equilibrium Solidification ◽  
Solid Liquid ◽  
Non Equilibrium

Abstract Solute segregation/redistribution model for some eutectic alloys is presented. The differential equation for the solute micro-segregation during solidification accompanied by the back-diffusion is formulated. The solution to this equation results in the definitions of: solidification path, solid/liquid (s/l) interface path and redistribution path. An equation for the estimation of the amount of equilibrium and non-equilibrium precipitates is also delivered. It is proved that the current model is universal one. Thus, the model reduces perfectly, mathematically to both description of diffusion-less solidification and model of equilibrium solidification.

Investigation of the non-equilibrium solidification microstructure of a Mg–4Al–2RE (AE42) alloy

2016 ◽  
Vol 51 (13) ◽  
pp. 6287-6294 ◽  
Author(s):  
Weihua Sun ◽  
Xiaoying Shi ◽  
Emre Cinkilic ◽  
Alan A. Luo
Keyword(s):  
Solidification Microstructure ◽  
Equilibrium Solidification ◽  
Non Equilibrium

scholarly journals A Three Dimensional Cellular Automata Model for Dendrite Growth in Non-Equilibrium Solidification of Binary Alloy

2015 ◽  
Vol 86 (12) ◽  
pp. 1490-1497 ◽  
Author(s):  
Yan Zhao ◽  
Rongshan Qin ◽  
Dengfu Chen ◽  
Xinming Wan ◽  
Yang Li ◽  
...  
Keyword(s):  
Cellular Automata ◽  
Binary Alloy ◽  
Three Dimensional ◽  
Dendrite Growth ◽  
Cellular Automata Model ◽  
Equilibrium Solidification ◽  
Non Equilibrium
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