【摘 要】
：
The microsegregation behavior of the Al-4.5 wt％Cu alloy solidified at different cooling rates under the alternating magnetic field (AMF) was investigated.The experimental results showed that the amount of non-equilibrium eutectics in the interdendritic re
【机 构】
：
State Key Laboratory of Advanced Special Steel and School of Materials Science and Engineering, Shan
论文部分内容阅读
The microsegregation behavior of the Al-4.5 wt％Cu alloy solidified at different cooling rates under the alternating magnetic field (AMF) was investigated.The experimental results showed that the amount of non-equilibrium eutectics in the interdendritic region decreased upon applying the AMF at the same cooling rate.The change in microsegregation could be explained quantificationally by the modifications of dendritic coarsening,solid-state back diffusion and convection in the AMF.The enhanced diffusivity in the solid owing to the AMF was beneficial for the improvement in microsegregation compared to the cases without an AMF.In contrast,the enhanced dendritic coarsening and forced convection in the AMF were found to aggravate the microsegregation level.Considering the contributions of the changes in above factors,an increase in solid diffusivity was found to be primarily responsible for the reduced microsegregation in the AMF.In addition,the microsegregation in the AMF was modeled using the analytical model developed by Voller.The calculated and experimental results were in reasonable agreement.
其他文献
Bobbin tool friction stir welding (BT-FSW) is a variant of conventional friction stir welding (FSW).It can be used to weld complex curvature structures and closed sections by adding an extra shoulder instead of a rigid backing anvil,which expands the pote
In recent studies,critical research interest exists in the thermo-mechanical analysis of the friction stir welding (FSW) process by numerical simulation.In this review,the thermo-mechanical analysis for FSW is overviewed regarding the computational approa
In this work,the high-strength Mg-5Zn-2Al-2Sn (ZAT522,in wt％) Mg alloys was obtained at 220 ℃ and 130 ℃ by a two-step equal channel angular pressing (ECAP).For each stage,two passes were used.The results showed a remarkable grain refinement after the firs
Refill friction stir spot welding,also known as friction spot welding (FSpW),is a solid-state welding process suitable for spot joining of lightweight materials.Through the efforts of improving joint quality for similar and dissimilar materials,for exampl
Surface mechanical attrition treatment (SMAT) was carried out on hot-rolled AZ31 Mg samples along two orthogonal directions;as a result,two types of gradient structures with different grain sizes and texture components in different layers were produced.Th
In the present work,the sheets of Zr-1Sn-0.3Nb-0.3Fe--0.1Cr alloy were hot rolled with different reductions (10％,30％,50％,and 60％) at 1023 K and 1073 K.The microstructure evolutions including grain microstructure,texture,and dislocation were investigated,u
Magnesium (Mg) alloys have been extensively used in various fields,such as aerospace,automobile,electronics,and biomedical industries,due to their high specific strength and stiffness,excellent vibration absorption,electromagnetic shielding effect,good ma
Friction stir lap welding of a DP1180 advanced ultrahigh strength steel was successfully carried out by using three welding tools with different pin lengths.The effects of the welding heat input and material flow on the microstructure evolution of the joi
The ultra-fine-grained ferrite (UFGF) with the size of less than 1 μm is often difficult to be obtained for low-alloyed steel in practical production processing.In this study,considering the rod and wire production process,a new method for preparing the U