Solidification Structure of 6063 Alloy under Pulsed Magnetic Field

The influences of pulsed magnetic field (PMF) on solidification structure of 6063 alloy were studied in this article. The results show that solidification structure of 6063 alloy can be refined with the application of PMF. The dendrite growth restrained and the macrostructure changed from large dendrite grains to fine equiaxed grains. The grain size decreased when the voltage increased from 0V to 600V. However, when the pulse frequency increased from 5Hz to 15Hz, the average grain size decreased continuously until reached a limit, and then the grains coarsened with further increase of the pulse frequency. The vibration caused by PMF not only made the temperature field of the melt uniform ,but also brook off the initial solidified grains formed on the cold wall of the mold, and spurs the grains to move to the center of melt which can be acted as nuclei.

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Effect of Low-Voltage Pulsed Magnetic Field on Solidified Structure of Superalloy K4169

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.423-426.725 ◽

2013 ◽

Vol 423-426 ◽

pp. 725-729

Author(s):

Xiao Hua Xie ◽

Quan Zhou ◽

Cheng Bo Xiao ◽

Xin Tang

Keyword(s):

Magnetic Field ◽

Grain Size ◽

Low Voltage ◽

Pulse Frequency ◽

Pulse Voltage ◽

Experimental Results ◽

Pulsed Magnetic Field ◽

Equiaxed Grains ◽

Dendritic Structures ◽

Refinement Effect

Effects of different pulse voltage and frequency on solidified structure of superalloy K4169 under low-voltage pulsed magnetic field (LVPMF) were investigated in this paper, and the related mechanism was also discussed. The experimental results show that grain of superalloy K4169 can be refined greatly by LVPMF treatment during the course of solidification. Growth of dendrite is restrained and primary grain is changed from large dendrites to smaller equiaxed grains. When the pulse voltage is at 0-280V, grain size of the alloy decreases as pulse voltage increases, and primary dendrites are fractured from well-developed dendrites into fine equiaxed grains and non-dendritic structures. When the pulse frequency is at 0-5Hz, the increase of pulse frequency enhances the refinement effect of LVPMF processing. With the increase of the pulse frequency, grain size of the alloy increases.

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Effects of Compound Treatment of Pulsed Magnetic Field and Mechanical Vibration on Solidified Structure of Mg97Y2Cu1 Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1061-1062.17 ◽

2014 ◽

Vol 1061-1062 ◽

pp. 17-22

Author(s):

Hao Zhang ◽

Quan Zhou ◽

Sen Zhang

Keyword(s):

Magnetic Field ◽

Grain Size ◽

Volume Fraction ◽

Mechanical Vibration ◽

Mold Temperature ◽

Pulse Frequency ◽

Pulse Voltage ◽

Pulsed Magnetic Field ◽

Second Phase ◽

Pouring Temperature

The influences of different pulse voltage, pulse frequency, pouring temperature and mold temperature on solidified structure of Mg97Y2Cu1alloy reinforced by long-period ordered structure with compound treatment of pulsed magnetic field and mechanical vibration were studied. The results show that grains of the alloy can be refined greatly with compound treatment. Primary phase degrades from developed dendrites into rosette-shaped crystal. Distribution of second phase is more uniform and continuous, and its volume fraction increases. When the pulse voltage is at 0-280V or the pulse frequency is at 1-10Hz, grain size of the alloy decreases dramatically as pulse voltage or pulse frequency increases. When the pouring temperature is at 660-750°C or the mold temperature is at 20-600oC, grain size of the alloy with compound treatment decreases grossly with the increase of the pouring temperature or the mold temperature.

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Grain Refinement of Superalloy K4169 with Low-Voltage Pulsed Magnetic Field Treatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.821-822.877 ◽

2013 ◽

Vol 821-822 ◽

pp. 877-882

Author(s):

Xiao Hua Xie ◽

Le Ping Chen ◽

Cheng Bo Xiao ◽

Xin Tang

Keyword(s):

Magnetic Field ◽

Low Voltage ◽

Mold Temperature ◽

Primary Phase ◽

Pulsed Magnetic Field ◽

Pouring Temperature ◽

Average Grain Size ◽

Magnetic Field Treatment ◽

Equiaxed Grains ◽

Refinement Effect

The influences of different pouring temperature and mold temperature on solidified structure of superalloy K4169 under low-voltage pulsed magnetic field (LVPMF) were investigated in the paper. The experimental results show that solidified structure of superalloy K4169 under LVPMF can be refined greatly with appropriate cooling rate of the alloy. The dendrite growth is restrained and the microstructure is changed from larger dendrite grains to smaller equiaxed grains. When the pouring temperature is at 1380 °C-1530 °C or the mold temperature is at 1000 °C-1300 °C, the increase of pouring temperature or mold temperature enhances the refinement effect of LVPMF processing. With the increase of the pouring temperature or the mold temperature, average grain size of the alloy decreases and the primary phase degrades from developed dendrites into equiaxed crystals under the LVPMF.

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Microstructural Refinement Process of Pure Magnesium by Pulse Magnetic Field Treatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.3964 ◽

2011 ◽

Vol 189-193 ◽

pp. 3964-3967

Author(s):

Bin Wang ◽

Ming Li Sun ◽

Jing De Chen ◽

Yong Bin Wei

Keyword(s):

Magnetic Field ◽

Pulse Magnetic Field ◽

Pulsed Magnetic Field ◽

Bulk Liquid ◽

Microstructural Refinement ◽

Average Grain Size ◽

Columnar Grains ◽

Refinement Process ◽

Inner Diameter ◽

Equiaxed Grains

The effects of pulsed magnetic field on the solidified structure of pure Mg were investigated. Fine uniform equiaxed grains are acquired in the whole ingot from the PMF treatment, in contrast with the coarse columnar grains observed in conventional casting, and the average grain size is refined to 260 m with a 5Hz PMF treatment. The mould size also affects the grain refinement and the most suitable inner diameter of the cylindrical mould is set at 50mm. Pulsed magnetic field increases melt convection during solidification, and the violent agitation causes warmer liquid to fracture the tip of columnar dendrites or to break off dendrite branches and promote the formation of an equiaxed structure, with the broken pieces transported into the bulk liquid acting as nuclei.

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Effect of Pulsed Magnetic Field on Structure Refinement of Pure Magnesium

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.154-155.46 ◽

2010 ◽

Vol 154-155 ◽

pp. 46-49

Author(s):

Bin Wang ◽

Ming Li Sun ◽

Qiang Wei

Keyword(s):

Magnetic Field ◽

Structure Refinement ◽

Pure Magnesium ◽

Pulsed Magnetic Field ◽

Processing Parameter ◽

Microstructural Refinement ◽

Optimal Processing ◽

Average Grain Size ◽

Columnar Grains ◽

Equiaxed Grains

A pulsed magnetic field (PMF) was introduced into the solidification of pure magnesium and the effect of structure refinement is investigated. The results show that remarkable microstructural refinement is achieved when the pulsed magnetic field is applied. The morphology is characterized as the columnar grains at the periphery and equiaxed grains at the core. The average grain size in the center of ingot is refined to 260m at the optimal processing parameter (5Hz, 200V). The pulsed magnetic field increases melt convection during solidification, as a result, the stress fractures the dendrites inwards from the mould wall, and the fractured dendrites act as nuclei, so the big columnar grains are prohibited.

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Effects of Pulsed Magnetic Field on the Microstructure and Mechanical Properties of Mg97Y2Zn1 Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1004-1005.123 ◽

2014 ◽

Vol 1004-1005 ◽

pp. 123-126 ◽

Cited By ~ 1

Author(s):

Jian Yin ◽

Xiu Jun Ma ◽

Jun Ping Yao ◽

Zhi Jian Zhou

Keyword(s):

Magnetic Field ◽

Mechanical Properties ◽

Grain Size ◽

Volume Fraction ◽

Pulsed Magnetic Field ◽

Second Phase ◽

Microstructure And Mechanical Properties ◽

Magnetic Field Treatment ◽

Semi Solid ◽

Strength And Plasticity

Effect of pulsed magnetic field treatment on the microstructure and mechanical properties of Mg97Y2Zn1 alloy has been investigated. When the pulsed magnetic field is applied on the alloy in semi-solid state, the α-Mg was modified from developed dendrite to fine rosette, resulting in a refined solidification microstructure with the grain size decreased from 4 mm to 0.5 mm. The volume fraction of the second phase ( X phase) increased by about 10 %. The yield strength, fracture strength and plasticity were improved by 21 MPa, 38 MPa and 2.4 %, respectively. The improvement of mechanical properties was attributed to the refined grain size and increased volume fraction of X phase.

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Microstructure Evolution and Grain Boundary Characteristics of Oriented Silicon Steel during Primary Recrystallization in a Pulsed Magnetic Field

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.139 ◽

2013 ◽

Vol 690-693 ◽

pp. 139-146 ◽

Cited By ~ 1

Author(s):

Li Hua Liu ◽

Li Juan Li ◽

Qi Jie Zhai

Keyword(s):

Magnetic Field ◽

Grain Size ◽

Magnetic Fields ◽

Grain Boundary ◽

Microstructure Evolution ◽

Silicon Steel ◽

Pulsed Magnetic Field ◽

Magnetic Annealing ◽

Grain Boundary Characteristics ◽

Boundary Characteristics

The effects of a 2 T pulsed magnetic field primary annealing process on microstructure evolution and grain boundary characteristics in two-stage cold-rolled silicon steel were examined. Pulsed magnetic annealing increased grain size through the application of relatively smaller intensity of magnetic fields (2 T), compared to steady magnetic annealing. The effect of increasing grain size may be attributed to the magnetic acceleration effect of boundary motion under magnetic pulse conditions. Pulsed magnetic annealing may serve to enhance the relative intensity of the {111} component and decrease the frequency of low-angle misorientations. Repeated magnetostriction induced by pulsed magnetic field applications may accelerate overall dislocation motion. These findings suggest that pulsed magnetic fields require relatively lower intensities than steady magnetic fields to achieve superior results, providing a potentially viable alternative for industrial annealing processes for electrical steels.

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Magnetic Annealing on GNO Electrical Steel Fe-3.25% Si

Materials Science Forum ◽

10.4028/www.scientific.net/msf.758.113 ◽

2013 ◽

Vol 758 ◽

pp. 113-117 ◽

Cited By ~ 2

Author(s):

Gilberto Alexandre Castello-Branco ◽

Jennifer Nadine Muller ◽

Cristiane Maria Basto Bacaltchuk

Keyword(s):

Magnetic Field ◽

Grain Size ◽

Electrical Steel ◽

Annealing Process ◽

Magnetic Annealing ◽

Average Grain Size ◽

Orientation Density ◽

Cold Rolled ◽

Small Grains ◽

Electrical Motors

Grain non-oriented electrical steel has its main application in electrical motors and its microstructure significantly influences their efficiency. The objective of this work was to investigate whether or not magnetic field applied during annealing process affects grain growth and the development of important texture components leading to an improvement of the magnetic properties. GNO Fe-3.25%Si 75% cold rolled specimens were annealed inside magnetic field with strength of 17 T at the temperature of 800°C for 3, 10 and 30 minutes. Results of average grain size after magnetic annealing showed a microstructure formed by small grains and a few very large grains. Magnetic field did not increase orientation density of {100} oriented grains and Goss grains but was able to increase density of θ fiber and decrease the density of γ fiber.

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Aging Behavior of Aluminum Alloy 6082 Subjected to Friction Stir Processing

Crystals ◽

10.3390/cryst8090337 ◽

2018 ◽

Vol 8 (9) ◽

pp. 337 ◽

Cited By ~ 1

Author(s):

Khaled Al-Fadhalah ◽

Fahad Asi

Keyword(s):

Grain Size ◽

Aluminum Alloy ◽

Aging Time ◽

Friction Stir Processing ◽

Aging Temperature ◽

Friction Stir ◽

Average Grain Size ◽

Different Temperatures ◽

Equiaxed Grains ◽

Electron Back Scattered Diffraction

The present work examined the effect of artificial aging on the microstructure, texture, and hardness homogeneity in aluminum alloy AA6082 subjected to friction stir processing (FSP). Aging was applied to FSP samples at three different temperatures (150 °C, 175 °C, and 200 °C) for a period of 1 h, 6 h, and 12 h. Microstructure analysis using optical Microscopy (OM) and Electron Back-Scattered Diffraction (EBSD) indicated that FSP produced fine equiaxed grains, with an average grain size of 6.5 μm, in the stir zone (SZ) due to dynamic recrystallization. Aging was shown to result in additional grain refinement in the SZ due to the occurrence of recovery and recrystallization with either increasing aging temperature and/or aging time. An optimum average grain size of 3–4 μm was obtained in the SZ by applying aging at 175 °C. This was accompanied by an increase in the fraction of high-angle grain boundaries. FSP provided a simple shear texture with a major component of B fiber. Increasing aging temperature and/or time resulted in the formation of recrystallization texture of a Cube orientation. In addition, Vickers microhardness was evaluated for the FSP sample, indicating a softening in the SZ due to the dissolution of the hardening precipitates. Compared to other aging temperatures, aging at 175 °C resulted in maximum hardness recovery (90 Hv) to the initial value of base metal (92.5 Hv). The hardness recovery is most likely attributed to the uniform distribution of fine hardening precipitates in the SZ when increasing the aging time to 12 h.

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