期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
Structures and macrosegregation of a 2024 aluminum alloy fabricated by direct chill casting with double cooling field 被引量:5
1
作者 Cheng Zhu Zhi-hao Zhao +3 位作者 Qing-feng Zhu Gao-song Wang Yu-bo Zuo Gao-wu Qin 《China Foundry》 SCIE CAS 2022年第1期1-8,共8页
Central region coarse grains and centerline segregation are common defects in aluminum ingots fabricated by direct chill(DC)casting.A double cooling field was introduced into the DC casting process to reduce these def... Central region coarse grains and centerline segregation are common defects in aluminum ingots fabricated by direct chill(DC)casting.A double cooling field was introduced into the DC casting process to reduce these defects,whereby the external cooling was supplied by the mold and water jets,and intercooling was achieved by inserting a rod of the same alloy into the molten pool along the central axis of the ingot.Rather than forming a good metallurgical interface during solid-liquid compound casting,in the present work,the purpose of inserting the rod is to enforce internal cooling and consequently decrease the sump depth.Moreover,the insertion provides more nucleation sites with the unmoltenα-Al particles.The structure and the macrosegregation of 2024 Al alloy ingots prepared by DC casting with and without the inserts were investigated.Results show that when the inserting position is 50 mm above the upper edge of the graphite ring,significant grain refinement in the central region of the ingot and a reduced centerline segregation are achieved. 展开更多
关键词 aluminum alloy direct chill casting double cooling field grain refinement MACROSEGREGATION
下载PDF
Prediction of hot tearing susceptibility of direct chill casting of AA6111 alloys via finite element simulations 被引量:4
2
作者 Dong-xu CHEN Rui-feng DOU +1 位作者 Jia-qiang HAN Jun-sheng WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第12期3161-3172,共12页
To predict hot tearing susceptibility(HTS)during solidification and improve the quality of Al alloy castings,constitutive equations for AA6111 alloys were developed using a direct finite element(FE)method.A hot tearin... To predict hot tearing susceptibility(HTS)during solidification and improve the quality of Al alloy castings,constitutive equations for AA6111 alloys were developed using a direct finite element(FE)method.A hot tearing model was established for direct chill(DC)casting of industrial AA6111 alloys via coupling FE model and hot tearing criterion.By applying this model to real manufacture processes,the effects of casting speed,bottom cooling,secondary cooling,and geometric variations on the HTS were revealed.The results show that the HTS of the billet increases as the speed and billet radius increase,while it reduces as the interfacial heat transfer coefficient at the bottom or secondary water-cooling rate increases.This model shows the capabilities of incorporating maximum pore fraction in simulating hot tearing initiation,which will have a significant impact on optimizing casting conditions and chemistry for minimizing HTS and thus controlling the casting quality. 展开更多
关键词 vehicle light-weighting AA6111 alloy direct chill casting hot tearing criterion pore fraction finite element simulation
下载PDF
Effect of harmonic magnetic field and pulse magnetic field on microstructure of high purity Cu during electromagnetic direct chill casting 被引量:3
3
作者 Lei Bao Da-zhi Zhao +3 位作者 Yin-ji Zhao Yong-hui Jia Xuan Wang Qi-chi Le 《China Foundry》 SCIE CAS 2021年第2期141-146,共6页
The effects of two types of magnetic fields,namely harmonic magnetic field(HMF)and pulse magnetic field(PMF)on magnetic flux density,Lorentz force,temperature field,and microstructure of high purity Cu were studied by... The effects of two types of magnetic fields,namely harmonic magnetic field(HMF)and pulse magnetic field(PMF)on magnetic flux density,Lorentz force,temperature field,and microstructure of high purity Cu were studied by numerical simulation and experiment during electromagnetic direct chill casting.The magnetic field is induced by a magnetic generation system including an electromagnetic control system and a cylindrical crystallizer of 300 mm in diameter equipped with excitation coils.A comprehensive mathematical model for high purity Cu electromagnetic casting was established in finite element method.The distributions of magnetic flux density and Lorentz force generated by the two magnetic fields were acquired by simulation and experimental measurement.The microstructure of billets produced by HMF and PMF casting was compared.Results show that the magnetic flux density and penetrability of PMF are significantly higher than those of HMF,due to its faster variation in transient current and higher peak value of magnetic flux density.In addition,PMF drives a stronger Lorentz force and deeper penetration depth than HMF does,because HMF creates higher eddy current and reverse electromagnetic field which weakens the original electromagnetic field.The microstructure of a billet by HMF is composed of columnar structure regions and central fine grain regions.By contrast,the billet by PMF has a uniform microstructure which is characterized by ultra-refined and uniform grains because PMF drives a strong dual convection,which increases the uniformity of the temperature field,enhances the impact of the liquid flow on the edge of the liquid pool and reduces the curvature radius of liquid pool.Eventually,PMF shows a good prospect for industrialization. 展开更多
关键词 high purity Cu pulse magnetic field harmonic magnetic field MICROSTRUCTURE sputtering target direct chill casting
下载PDF
Microstructure and mechanical properties of Mg-Nd-Zn-Zr billet prepared by direct chill casting 被引量:2
4
作者 Xingwei Zheng Jie Dong Shiming Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS 2018年第1期95-99,共5页
High-quality Mg-Nd-Zn-Zr magnesium alloy billets with diameter of 200 mm were successfully prepared by direct chill(DC)casting.The results show that microstructures of the as-cast billet prepared by DC casting are mai... High-quality Mg-Nd-Zn-Zr magnesium alloy billets with diameter of 200 mm were successfully prepared by direct chill(DC)casting.The results show that microstructures of the as-cast billet prepared by DC casting are mainly composed of equiaxed a-Mg and Mg 12 Nd eutectic compound distributing along the grain boundaries.The average grain size decreases along the radius of the billet.And the alloying elements of Nd and Zn distribute homogeneously across the large billet.The optimum process parameters for DC casting of the Mg-Nd-Zn-Zr magnesium alloy billet with diameter of 200 mm have been experimentally determined as follows:casting temperature 710℃ and casting speed 80 mm/min. 展开更多
关键词 Magnesium alloy direct chill casting MICROSTRUCTURE Mechanical properties
下载PDF
Effect of Low Frequency Electromagnetic Field on Macrosegregation of Horizontal Direct Chill Casting Aluminum Alloys
5
作者 Zhihao ZHAO, Jianzhong GUI, Jie DONG and Beijiang ZHANGThe Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, P.O. Box 314, Northeastern University, Shenyang 110004, ChinaPh.D. candidate, 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第1期75-78,共4页
The horizontal direct chill (HDC) casting process is a well-established production route for aluminum alloy ingot but the ingot may suffer from macrosegregation sometimes. In order to control the defect, a low frequen... The horizontal direct chill (HDC) casting process is a well-established production route for aluminum alloy ingot but the ingot may suffer from macrosegregation sometimes. In order to control the defect, a low frequency electromagnetic field has been applied in HDC casting process and the relevant influence has been studied. The results show that application of low frequency electromagnetic field can reduce macrosegregation in HDC casting process; and two main parameters of electromagnetic field density and frequency, have great influences on the solution distribution along the diameter of ingot. Moreover, the mechanisms of reduction of macrosegregation by electromagnetic field have been discussed. 展开更多
关键词 Low frequency electromagnetic field Horizontal direct chill casting MACROSEGREGATION Aluminum alloy
下载PDF
Effect of casting speed on surface quality of horizontal direct chill casting 7075 aluminum alloy ingot 被引量:3
6
作者 Qingfeng ZHU Zhihao ZHAO Jianzhong CUI Xiangjie WANG Ke QIN 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2011年第5期399-404,共6页
7075 aluminum alloy ingot with the diameter izontal direct chill casting in different casting of 100 mm has been produced by horspeed. The effect of the casting speed on the ingot surface and subsurface layer was stud... 7075 aluminum alloy ingot with the diameter izontal direct chill casting in different casting of 100 mm has been produced by horspeed. The effect of the casting speed on the ingot surface and subsurface layer was studied by surface observation and subsurface structure analysis. It was found that increasing the casting speed results in the adding of segregation knots in the ingot surface. The thickness of the dendrite microstrueture layer in the subsurface reduces with increasing the casting speed. And the elements of Zn, Cu and Mg enrich in the coarse dendrite microstructure layer of the ingot. 展开更多
关键词 Horizontal direct chill casting casting speed 7075 aluminumalloy Surface quality
原文传递
EFFECT OF LOW-FREQUENCY ELECTROMAGNETIC FIELD ON THE AS-CASTING MICROSTRUCTURES AND MECHANICAL PROPERTIES OF HDC 2024 ALUMINUM ALLOY 被引量:4
7
作者 Q.F. Zhu Z.H. Zhao J.Z. Cui Y.B. Zuo F. Qu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2008年第3期205-210,共6页
The influences of the low frequency electromagnetic field on the horizontal direct chill casting process were investigated experimentally. Ingots of 2024 aluminum alloy with a cross size of 40 mm× 200 mm were pro... The influences of the low frequency electromagnetic field on the horizontal direct chill casting process were investigated experimentally. Ingots of 2024 aluminum alloy with a cross size of 40 mm× 200 mm were produced by the conventional horizontal chill casting process and low frequency electromagnetic horizontal chill casting processre- spectively. The as-cast structures and the mechanical property of the ingots were examined. The results showed that the low frequency electromagnetic field could sub- stantially refine the microstructures and pronouncedly reduce the macrosegregation in the horizontal direct chill casting process. Moreover, the surface quality of the ingot was prominently improved by the low frequency electromagnetic field. The fracture strength and elongation percentage of the ingot was increased with the low frequency electromagnetic field. 展开更多
关键词 Horizontal direct chill casting Low frequency electromagnetic field 2024 aluminum alloy MICROSTRUCTURES MACROSEGREGATION
下载PDF
Efects of low frequency electromagnetic ield on surface quality, microstructure and hot-tearing tendency of semi-continuous casting ZK60 magnesium alloy billets 被引量:3
8
作者 Zhang Zhiqiang Le Qichi +1 位作者 Bao Lei Cui Jianzhong 《China Foundry》 SCIE CAS 2013年第6期351-354,共4页
The low frequency electromagnetic field was applied during direct chill(DC) semi-continuous casting of the ZK60 magnesium alloy billets. Effects of low frequency electromagnetic field on surface quality, microstructur... The low frequency electromagnetic field was applied during direct chill(DC) semi-continuous casting of the ZK60 magnesium alloy billets. Effects of low frequency electromagnetic field on surface quality, microstructure and hot-tearing tendency of Φ500 mm ZK60 magnesium alloy billets were investigated. The results showed that with the application of the low frequency electromagnetic field, the surface quality of the ZK60 magnesium alloy billets is markedly improved and the depth of cold fold is decreased. The microstructure of the billets is also significantly refined. Besides, the distribution of the grain size is relatively uniform from the billet surface towards its center, where the average grain size is 42 μm at surface and 50 μm at center. It also shows that the hot-tearing tendency of DC semi-continuous casting ZK60 magnesium alloy billets is significantly reduced under low frequency electromagnetic field. 展开更多
关键词 ZK60 magnesium alloy billets direct chill casting low frequency electromagnetic field REFINEMENT
下载PDF
Effect of withdrawal rate on microstructure of a hypoeutectic Al-Si alloy by low superheat DC casting 被引量:1
9
作者 Zhao Dazhi Liu Fang +2 位作者 Yu Fuxiao Hong Tao Zuo Liang 《China Foundry》 SCIE CAS 2013年第3期172-175,共4页
To obtain the billet with homogeneous and spheroidized primary grains is the key step in the semi- solid forming process. Among the semi-solid billet preparation methods, the process of low-superheat direct chill (DC... To obtain the billet with homogeneous and spheroidized primary grains is the key step in the semi- solid forming process. Among the semi-solid billet preparation methods, the process of low-superheat direct chill (DC) casting is simpler and more effective. In this study, the billets of AISi7Mg alloy were prepared by low- superheat DC casting at various withdrawal rates. The effect of withdrawal rate on the surface quality of the billets was investigated, and the evolution mechanism of the microstructural morphology in the billets was analyzed. The results show that the periodic corrugations and a large quantity of fine shrinkage pits appear in the billet surface when the withdrawal rate is 100 mm.min-1, and the above defects in the billet surface can be eliminated completely when the withdrawal rate is above 150 mm.min-1. But when the withdrawal rate is too fast (250 mm.min-1), the primary a grains, except the ones in the billet center, have not enough time for ripening due to the high silidification rate, and will solidify as the dendrite structure. When the withdrawal rate is between 150 - 200 mm.min-1, the dendritic growth of the primary a grains is effectively inhibited, and a billet of AISi7Mg alloy with a smooth surface and homogeneous, fine, non-dendritic grains can be obtained. 展开更多
关键词 direct chill casting AlSi7Mg alloy withdrawal rate
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部