In this study the partially divorced eutectic microstructure ofα-Mg andβ-Mg17Al12was investigated by electron backscatter diffraction,transmission electron microscopy,and phase-field modeling in hypoeutectic Mg-Al a...In this study the partially divorced eutectic microstructure ofα-Mg andβ-Mg17Al12was investigated by electron backscatter diffraction,transmission electron microscopy,and phase-field modeling in hypoeutectic Mg-Al alloys.The orientation relationships between the individual eutecticαgrains,eutecticβphase,and primaryαgrains were investigated.While the amount of eutectic morphology is primarily determined by the Al content,the in-depth microstructure analyses and the phase-field simulation suggest non-interactive nucleation and growth of eutecticαphase in theβphase grown on the interdendritic primaryαdendrites.Also,phase-field simulations showed a preferred nucleation sequence where theβphase nucleates first and subsequently triggers the nucleation of eutecticαphase at the movingβphase solidification front,which supports the microstructural analysis results.展开更多
The phase-field method has emerged as the method of choice for the description of microstructure evolution and phase transitions in metallic materials.Following general thermodynamic laws a set of evolution equations ...The phase-field method has emerged as the method of choice for the description of microstructure evolution and phase transitions in metallic materials.Following general thermodynamic laws a set of evolution equations for the structural variables of the system,the so called phase-fields,are derived.The paper reviews shortly the theoretical background of the multi-phase-field.Different examples demonstrating the applicability of the method to technical steels will be presented ranging from deformation of the dendritic strand shell during peritectic transformation,grain growth in Austenite to stress driven growth of Pearlite.展开更多
The complex interplay between the rapid martensitic transformation and the plastic relaxation during martensitic transformation in low-carbon steel is investigated using a combined phase-field and phenomenological cry...The complex interplay between the rapid martensitic transformation and the plastic relaxation during martensitic transformation in low-carbon steel is investigated using a combined phase-field and phenomenological crystal plasticity approach.The large transformation-induced deformations and local lattice rotations are rigorously described within the finite strain framework.The study reveals that plastic relaxation plays a crucial role in accommodating the transformation-induced deformations of martensite in the parent austenite phase.By systematically varying the plastic slip rate,imposed cooling rate,and carbon content,the simulations provide insights into the interdependence between these factors,contributing to a better understanding of the martensitic transformation process and the resulting microstructures.The phenomenological crystal plasticity model effectively relates the plastic relaxation rate to the rate of martensitic transformation with a significant time scale difference between the two processes.The findings contribute to a deeper understanding of the interplay between the rapid martensitic transformation and the requirement for plastic deformation.展开更多
基金supported by the Fundamental Research Program of Korea Institute of Materials Science(PNK7760 and PNK7770)the National Research Foundation of Korea(2020R1A2C2008416 and 2021M3H4A6A01049712)。
文摘In this study the partially divorced eutectic microstructure ofα-Mg andβ-Mg17Al12was investigated by electron backscatter diffraction,transmission electron microscopy,and phase-field modeling in hypoeutectic Mg-Al alloys.The orientation relationships between the individual eutecticαgrains,eutecticβphase,and primaryαgrains were investigated.While the amount of eutectic morphology is primarily determined by the Al content,the in-depth microstructure analyses and the phase-field simulation suggest non-interactive nucleation and growth of eutecticαphase in theβphase grown on the interdendritic primaryαdendrites.Also,phase-field simulations showed a preferred nucleation sequence where theβphase nucleates first and subsequently triggers the nucleation of eutecticαphase at the movingβphase solidification front,which supports the microstructural analysis results.
文摘The phase-field method has emerged as the method of choice for the description of microstructure evolution and phase transitions in metallic materials.Following general thermodynamic laws a set of evolution equations for the structural variables of the system,the so called phase-fields,are derived.The paper reviews shortly the theoretical background of the multi-phase-field.Different examples demonstrating the applicability of the method to technical steels will be presented ranging from deformation of the dendritic strand shell during peritectic transformation,grain growth in Austenite to stress driven growth of Pearlite.
基金funding by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-grant SH 657/3-1.
文摘The complex interplay between the rapid martensitic transformation and the plastic relaxation during martensitic transformation in low-carbon steel is investigated using a combined phase-field and phenomenological crystal plasticity approach.The large transformation-induced deformations and local lattice rotations are rigorously described within the finite strain framework.The study reveals that plastic relaxation plays a crucial role in accommodating the transformation-induced deformations of martensite in the parent austenite phase.By systematically varying the plastic slip rate,imposed cooling rate,and carbon content,the simulations provide insights into the interdependence between these factors,contributing to a better understanding of the martensitic transformation process and the resulting microstructures.The phenomenological crystal plasticity model effectively relates the plastic relaxation rate to the rate of martensitic transformation with a significant time scale difference between the two processes.The findings contribute to a deeper understanding of the interplay between the rapid martensitic transformation and the requirement for plastic deformation.
