scholarly journals Effect of Coil Configuration Design on Al Solidified Structure Refinement

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 153
Author(s):  
Jing Zhao ◽  
Ji-hao Yu ◽  
Ke Han ◽  
Hong-gang Zhong ◽  
Ren-xing Li ◽  
...  
Keyword(s):  
Structure Refinement ◽  
Experimental Results ◽  
Configuration Design ◽  
Coil Design ◽  
Grain Sizes ◽  
Refinement Effect

This paper outlines our effort to optimize PMO (Pulsed Magneto-Oscillation) design in order to improve the efficiency of ingot manufacturing. SPMO-H (Simplified Surface Pulse Magneto-Oscillation) and CPMO-H (Simplified Compound Pulse Magneto-Oscillation) were presented on the basis of SPMO (Surface Pulse Magneto-Oscillation) and CPMO (Compound Pulse Magneto-Oscillation). Our numerical and experimental results showed that optimized PMO coil design offered us a device that enabled the operator to examine and operate the melt more convenient without losing the efficiency and decreasing refinement effect. Our work also showed the distance between the coil and the melt surface had little effect on the grain sizes refined. Therefore, in ingot production, the dropping of melt surface is not a problem for PMO application.

scholarly journals Effect of Coil Configuration Design on Al Solidified Structure Refinement

2019 ◽  
Author(s):  
Jing Zhao ◽  
Ji-hao Yu ◽  
Ke Han ◽  
Hong-gang Zhong ◽  
Ren-xing Li ◽  
...  
Keyword(s):  
Structure Refinement ◽  
Configuration Design ◽  
Coil Design ◽  
Special Configuration ◽  
Distance Range ◽  
Grain Sizes

This paper outlines our effort on optimizing Pulsed Magneto-Oscillation (PMO) design in order to improve the efficiency of ingot manufacturing under PMO. Our calculation and experiment provided optimized PMO coil design and special configuration. Our optimized PMO design offered us a device that enabled the operator to examine and operate the melt without losing the efficiency. In one of the designs, the equipment even refined the grain sizes. Our work also showed an optimized distance range between the coil and the melt surface that maximized the refinement effects.

Effect of Al-5Ti-B Refiner on Microstructure of Al-5Cu Aluminum Alloy

2011 ◽  
Vol 365 ◽  
pp. 89-93
Author(s):  
De Quan Shi ◽  
Yang Shao ◽  
Gui Li Gao ◽  
Zhi Wei Gao ◽  
Xu Dong Wang
Keyword(s):  
Aluminum Alloy ◽  
Holding Time ◽  
Experimental Results ◽  
Optimal Parameters ◽  
Fine Needle ◽  
Grain Sizes ◽  
Holding Temperature ◽  
Precipitation Phase ◽  
Refinement Effect

By using the Olympus GX71 microscope, the effects of Al-5Ti-B addition, holding time and holding temperature on the microstructure of Al-5Cu alloy have been studied, and the influencing rules have been got. The experimental results show that the refinement effect of Al-5Ti-B is very remarkable and the grain sizes of Al-5Cu become small. The optimal parameters are as follows. The refiner addition is 2%-3%, and the holding time is 15 minutes, and the holding temperature is 720°C-740°C. When the 2%-3% Al-5Ti-B refiner is added, the Al3Ti is fine needle shape and the precipitation phase Al2Cu is round flake shape or reticular shape. Simultaneously, the dendrites have minimum spacing, and the microstructure becomes fine and uniform.

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

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.

Effects of Electromagnetic Agitation on Crystal Growth during the Pure Aluminum Slow Cooling Process

2020 ◽  
Vol 993 ◽  
pp. 398-403
Author(s):  
Xiang Jie Wang ◽  
Fang Yu ◽  
Peng Wei Li ◽  
Wei Sun ◽  
Hong Juan Tan ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Structure Refinement ◽  
Pure Aluminum ◽  
Low Frequency ◽  
Casting Process ◽  
Cooling Process ◽  
Continuous Casting Process ◽  
Slow Cooling ◽  
Fine Grain ◽  
Refinement Effect

Refining grains are important to obtain sound cast billets suitable for further processing. The structure refinement of low frequency electromagnetic field (LFEF) during the aluminum alloy semi-continuous casting process has been confirmed by many researchers. In this work, effects of the electromagnetic agitation on the crystal growth were investigated during the pure aluminum slow cooling process. The results showed that the grain refinement effect by electromagnetic agitation mainly occurred at the first half period of crystal growth. With increasing of applying LFEF treated time, the fine grain occupied the whole section of ingot, and the ratio of fine grain zone to the whole section was proportional to the treated time.

Light angular distribution and modulation transfer function of a fluorescent screen excited by an electron beam

1979 ◽  
Vol 57 (12) ◽  
pp. 2190-2193 ◽  
Author(s):  
G. E. Giakoumakis ◽  
C. D. Nomicos ◽  
P. C. Euthymiou
Keyword(s):  
Electron Beam ◽  
Angular Distribution ◽  
Theoretical Model ◽  
Transfer Function ◽  
Modulation Transfer Function ◽  
Experimental Results ◽  
Modulation Transfer ◽  
Grain Sizes ◽  
Phosphor Screen ◽  
Fluorescent Screen

The angular distribution of the light emitted from a ZnCdS(Ag) phosphor screen excited by an electron beam is measured for different thicknesses of the screen and for two grain sizes. This angular distribution is found to have a divergence from the Lambert law. A theoretical model is proposed leading to an equation fitting to the experimental results. Using this equation the modulation transfer function (MTF) of the screen was calculated.

Thermodynamic Stabilization of Grain Size in Nanocrystalline Metals

2012 ◽  
Vol 715-716 ◽  
pp. 323-328 ◽  
Author(s):  
Carl C. Koch ◽  
Ron O. Scattergood ◽  
Brian K. VanLeeuwen ◽  
Kristopher A. Darling
Keyword(s):  
Grain Size ◽  
Annealing Temperature ◽  
Experimental Results ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
Thermodynamic Stabilization ◽  
Solute Atoms ◽  
Zr Alloy

This paper describes the stabilization of nanocrystalline grain sizes in Pd and Fe by the addition of Zr solute atoms. The grain size as a function of annealing temperature was measured by both x-ray diffraction (XRD) line broadening analysis and microscopy methods. The latter methods showed that the XRD grain size measurements for the samples annealed at the higher temperatures were not valid. It appears that thermodynamic stabilization may still be operative in the Fe-4at.% Zr alloy but not in the Pd-19at.% Zr alloy from the experimental results and calculations of the enthalpy of segregation.

scholarly journals Effects of Continuous and Pulsed Ultrasonic Treatment on Microstructure and Microhardness in Different Vertical Depth of ZL205A Castings

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4240
Author(s):  
Gang Lu ◽  
Yisi Chen ◽  
Qingsong Yan ◽  
Pengpeng Huang ◽  
HongXing Zhan ◽  
...  
Keyword(s):  
Ultrasonic Treatment ◽  
Boundary Segregation ◽  
Propagation Distance ◽  
Solute Redistribution ◽  
Sampling Depth ◽  
Grain Sizes ◽  
Ultrasound Propagation ◽  
Solidification Interface ◽  
Pulsed Ultrasonic ◽  
Refinement Effect

In this paper, in order to improve the performance of the ZL205A castings, continuous ultrasonic and pulsed ultrasonic treatments were applied to the melted alloy to study the effect of ultrasound propagation distance on microstructure and microhardness. The results indicated that ZL205A grains were significantly refined by ultrasonic vibration, but the refinement effect became weak gradually with the increase of sampling depth. The minimum grain sizes were 103.2 μm and 122.5 μm respectively in continuous and pulsed ultrasonic treatment. Grain boundary segregation also became more serious and coarser with the increase of vertical depth. In addition, microhardness and vertical depth are not positively correlated linearly. As the vertical depth increased, microhardness first decreased and then increased, the maximum hardnesses were 73.9 HV and 72.84 HV, respectively, in the two process modes. According to the experiment results and available studies, the mechanism of ultrasonic treatment maybe that: the cooling rate of solidification interface front increased by cavitation and streaming, thus changing the solute redistribution behavior of the ZL205A melt.

Grain Refinement and Nuclei Formation Mechanism of Ni-Based Superalloy K417 with Low Voltage Pulsed Magnetic Casting

2010 ◽  
Vol 654-656 ◽  
pp. 428-431
Author(s):  
Yuan Sheng Yang ◽  
Xiao Ping Ma ◽  
Ying Ju Li
Keyword(s):  
Magnetic Field ◽  
Cooling Rate ◽  
Grain Refinement ◽  
Formation Mechanism ◽  
Low Voltage ◽  
Experimental Results ◽  
Pulsed Magnetic Field ◽  
Melt Flow ◽  
Refinement Mechanism ◽  
Refinement Effect

Low Voltage Pulsed Magnetic Casting (LVPMC) is developed for grain refinement castings in recent years. This paper investigates the grain refinement effect of LVPMC on superalloy K417 and deals with the effects of cooling rate and superheating on grain refinement, as well as grain refinement mechanism. The experimental results show that the grains in the alloy are equiaxed and refined to 60 m averagely. The melt flow and Joule heat during solidification are modeled and simulated to reveals the grain refinement mechanism. It is considered that the melt vibration and convection caused by the pulsed magnetic field, as well as cooling rate and superheating contribute to the refinement of solidified grains.

The origin of nuclei and the refinement mechanism for solidified superalloy IN718 under pulsed magnetic field

2009 ◽  
Vol 24 (12) ◽  
pp. 3689-3692 ◽  
Author(s):  
Xiaoping Ma ◽  
Yingju Li ◽  
Yuansheng Yang
Keyword(s):  
Magnetic Field ◽  
Grain Refinement ◽  
Mold Wall ◽  
Mold Temperature ◽  
Experimental Results ◽  
Pulsed Magnetic Field ◽  
Mold Surface ◽  
Refinement Mechanism ◽  
Equiaxed Grains ◽  
Refinement Effect

The grain refinement effect of a pulsed magnetic field on superalloy IN718 was investigated. The experimental results show that fine equiaxed grains are acquired under the pulsed magnetic field. The refinement effect of the pulsed magnetic field is affected by the mold temperature. And the mixed grains are found in the solidified microstructures under the pulsed magnetic field. The origin of nuclei under the pulsed magnetic field is from the mold wall because of the rough mold surface, the undercooling, and the melt vibration, which all contribute to the refinement of solidified grains.

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