Phase-Field Modeling of Recrystallization - Effects of Second-Phase Particles on the Recrystallization Kinetics

2007 ◽  
Vol 558-559 ◽  
pp. 1189-1194
Author(s):  
Yoshihiro Suwa ◽  
Yoshiyuki Saito ◽  
Hidehiro Onodera
Keyword(s):  
Phase Field ◽  
Subgrain Size ◽  
Second Phase ◽  
Recrystallization Kinetics ◽  
Field Modeling ◽  
Subgrain Growth ◽  
Second Phase Particles ◽  
Field Methodology ◽  
The Mean ◽  
Polycrystalline Structures

The effects of second-phase particles on the recrystallization kinetics in two-dimensional polycrystalline structures were investigated. Numerical simulations of recrystallization were performed by coupling the unified subgrain growth theory with a phase-field methodology. Simple assumptions based on experimental observations were utilized for preparing initial microstructures. The following results were obtained: (1) The presence of second-phase particles retarded recrystallization speeds. (2) If the mean subgrain size was small enough recrystallized region covered whole system for various values of the particle fraction, f. (3) On the other hand, if the mean subgrain size was not small enough the progress of recrystallization was frozen at some point.

Phase-field modeling the effect of misfit on the precipitation of the second-phase particles and grain coarsening

2015 ◽  
Vol 100 ◽  
pp. 166-172 ◽  
Author(s):  
Yongbiao Wang ◽  
Liming Peng ◽  
Yujuan Wu ◽  
Yan Zhao ◽  
Yongxin Wang ◽  
...  
Keyword(s):  
Phase Field ◽  
Second Phase ◽  
Phase Field Modeling ◽  
Grain Coarsening ◽  
Field Modeling ◽  
Second Phase Particles

Structural Changes in a 9%Cr Creep Resistant Steel during Creep Test

2012 ◽  
Vol 715-716 ◽  
pp. 895-900
Author(s):  
Valeriy Dudko ◽  
Andrey Belyakov ◽  
Vladimir Skorobogatykh ◽  
Izabella Schenkova ◽  
Rustam Kaibyshev
Keyword(s):  
Structural Changes ◽  
Subgrain Size ◽  
Large Strain ◽  
Particle Growth ◽  
Second Phase ◽  
Second Phase Particles ◽  
Creep Rupture Test ◽  
Lath Structure ◽  
Creep Regime ◽  
Effective Stabilization

Structural changes in a 9%Cr martensitic steel after 1%, 4% creep and creep rupture test at 650°C and stress of 118 MPa were examined. Heat treatment provided the formation of tempered martensite lath structure (TMLS) in the steel. The precipitations of second phase particles along block and lath boundaries provide effective stabilization of the TMSL under annealing/aging condition. This structure hardly changed under creep conditions in grip portion of crept sample. Significant coarsening of both the second phase particles and the martensite laths takes place in neck portion. In addition, the latter ones lose their original morphology and are replaced by large strain-induced subgrains. It should be noted that the increase of subgrain size is in almost direct proportion to the particle growth during the creep to 4% strain. The rapid growth of martesite laths followed by their evolution to deformation subgrains takes place within the tertiary creep regime.

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.

Effects of Heat Treatment on Corrosion of Zr-1.0Nb-1.0Sn-0.1Fe

2005 ◽  
Vol 475-479 ◽  
pp. 1401-1404
Author(s):  
J.H. Baek ◽  
Yong Hwan Jeong
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Annealing Time ◽  
Tetragonal Phase ◽  
Second Phase ◽  
Tetragonal Zro2 ◽  
Monotectoid Reaction ◽  
Second Phase Particles ◽  
Mean Size ◽  
The Mean

The effects of annealing at 570oC and 640oC on the microstructural and corrosion characteristics for Zr-1.0Nb-1.0Sn-0.1Fe alloy were elucidated. After annealing at 570oC below the temperature of a monotectoid reaction in the Zr-Nb system, both orthorhombic Zr3Fe and the bcc b-Nb particles were uniformly found and the mean size of the second phase particles was increased with an increasing of the annealing time. In the case of an annealing at 640oC for 2 h above the monotectoid reaction temperature, the Zr3Fe was observed intermittently and after a longer annealing of 1000 h the b-Zr particles were well developed. The corrosion resistance after the 570oC anneal was improved as the annealing time increased, while that after the 640oC anneal decreased as the annealing time increased. The fraction of the tetragonal phase within the ZrO2 oxide increased as the corrosion resistance was improved. It was concluded that the equilibrium Nb concentration and the formation of the tetragonal ZrO2 due to the b-Nb phase would lead to improving the corrosion resistance of the alloy.

Phase-field Model for Diffusional Phase Transformations in Elastically Inhomogeneous Polycrystals

2011 ◽  
Vol 172-174 ◽  
pp. 1084-1089 ◽  
Author(s):  
Tae Wook Heo ◽  
Saswata Bhattacharyya ◽  
Long Qing Chen
Keyword(s):  
Grain Boundary ◽  
Phase Field ◽  
Field Model ◽  
Boundary Segregation ◽  
Phase Field Model ◽  
Transformation Process ◽  
Second Phase ◽  
Perturbation Scheme ◽  
Local Pressure ◽  
Second Phase Particles

A phase-field model is described for predicting the diffusional phase transformation process in elastically inhomogeneous polycrystals. The elastic interactions are incorporated by solving the mechanical equilibrium equation using the Fourier-spectral iterative-perturbation scheme taking into account elastic modulus inhomogeneity. A number of examples are presented, including grain boundary segregation, precipitation of second-phase particles in a polycrystal, and interaction between segregation at a grain boundary and coherent precipitates inside grains. It is shown that the local pressure distribution due to coherent precipitates leads to highly inhomogeneous solute distribution along grain boundaries.

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