|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Effect of Pouring Process on the Microstructures of Semi-Solid AlSi_7Mg Alloy显示文摘The effect of different pouring temperatures and different pouring heights, the distance between the mouth of the pouring ladle and the top of the mold, on the microstructure of AlSi7Mg alloy have been researched in the paper. When the pouring temperature is close to the liquidus temperature, the primary α-Al in the billets of AlSi7Mg alloy solidified into spherical and nodular fine grains distributed homogeneously. The optimum pouring temperature for semi-solid AlSi7Mg billet with spherical or nodular primary α-Al is 615℃. At the same pouring temperature, the higher the pouring ladle, the more easily the spherical and nodular primary α-Al obtained in the semi-solid AlSi7Mg billet. When the pouring temperature is close to the liquidus temperature and the pouring ladle is relatively high, it is the great cooling rate, the flow of the molten alloy caused by pouring and the large simultaneous solidification region induced by the near liquidus temperature, that promote the formation of spherical or nodular primary α-Al. | Weimin MAO, Chenglin CUT, Aimin ZHAO, Jilian YANG and Xueyou ZHONG Foundry Institute, University of Science and Technology Beijing, Beijing 100083, China | 2001 | Journal of Materials Science & Technology2001，17，6： | 17 |
| 2 | Preparation for Semi-Solid Aluminum Alloy Slurry under Weak Electromagnetic Stirring Conditions显示文摘倒温度的效果,突然电磁与低力量激动人心然后浸泡 AISi7Mg 合金的微观结构上的处理被调查。Theresults 表演如果 AISi7Mg 合金在 630 或 650 deg C 被倒并且同时在一短时间在低力量由一块电磁的地搅动了,流的过程能容易被控制,大多数团结的主要 alpha-AI 谷物变得球形并且仅仅他们的一些象 arerosette 一样。弱电磁激动人心使温度地更同类并且让主要 alpha-AI 谷物在一个更大的区域分散,它导致主要 alpha-AI 谷物的球形的微观结构。当 AISi7Mg 合金以半固体状态被浸泡或再热时,主要 a-AI 谷物进一步成熟,他们变得更球形,它对 AISi7Mg 合金形成的半固体有利。 | Weimin MAO Yuelong BAI Guoxing TANG | 2006 | Journal of Materials Science & Technology2006，22，4： | 17 |
| 3 | Analysis of Micro-texture during Secondary Recrystallization in a Hi-B Electrical Steel显示文摘The understanding of Goss texture in Hi-B electrical steels possesses significant industrial and academic value, thus attracts worldwide attention. The prevailing models for sharp Goss texture formation during secondary recrystallization are CSL (coincident site lattice) boundary theory and HE (high energy) boundary theory. These theories stress the key factor of preferred growth and the difference between them only lies in the specific selection manner. This work examined the texture gradient in primarily recrystallized sheet and demonstrated its possible influence on the formation of secondary grains, and then determined the micro- texture during different stages of secondary recrystallization using EBSD (electron back-scattered diffraction) technique, finally analyzed a special type of secondary grains with near Brass orientation, which were detected in the later stage of secondary recrystallization, and discussed its origin and effect in terms of surface energy effect. The results indicate that texture gradient in primarily recrystallized sheet will lead to a multi-stage formation of Goss texture, namely, early stage of secondary grains with various orientations in subsurface region, intermediate stage of preferred growth of Goss grains into center layer and re-grow back to the surface and the final stage of Goss grain growth by swallowing slowly the island grains with the help of H2 atmosphere. | Mengqi Yan Hao Qian Ping Yang Weimin Mao Qiwu Jian Wenxu Jin | 2011 | Journal of Materials Science & Technology2011，27，11： | 16 |
| 4 | Microstructure characteristics and mechanical properties of rheocasting 7075 aluminum alloy显示文摘The microstructure characteristics and mechanical properties of 7075 aluminum alloy produced by a new rheoforming technique,under as-cast and optimized heat treatment conditions,were investigated.The present rheoforming combined the innovatively developed rheocasting process,named as ICSPC(inverted coneshaped pouring channel)process,and the existing HPDC(high pressure die casting)process.The experimental results show that the ICSPC can be used to prepare high quality semi-solid slurry for the subsequent die casting.Compared with conventional HPDC process,the ICSPC process can improve the microstructures and mechanical properties of the cast tensile samples.An optimized heat treatment results in significant improvement in ultimate tensile strength.However,the ductility of the samples,both under as-cast and optimized heat treatment conditions,are relatively poor. | Yang Bin Mao Weimin Song Xiaojun | 2013 | China Foundry2013，10，5： | 8 |
| 5 | Microstructure Study on Semi-solid 60Si2Mn during Compressing显示文摘The microstructure behavior and deformation mechanism of semi-solid 60Si2Mn fabricated by electromagnetic stirring under different deformation conditions during thixoforming are studied by means of Gleeble-1500 thermal-strain-stress simulator. The micro- structure of deformed 60Si2Mn and that of the non-deformed are compared. The results show that the grain size within deformation zone decreases as the amount of deformation increases or deformation temperature decreases, but deformation fate has small effect on grain size when the rate is very low. Besides, there is a critical amount of deformation to reduce grain size. These results offer theoretical and experimental basis for further producing semi-solid material with high melting temperature and direct forming of semi-solid slurry. | Yonglin Kang, Xiongfei Yang, Renbo Song, Weimin Mao, Maosheng Yang (Material Science & Engineering School, University of Science and Technology Beijing, Beijing 100083, China) | 2001 | Journal of University of Science and Technology Beijing2001，8，2： | 7 |
| 6 | Distribution of Microelements and Their Influence on the Corrosion Behavior of Aluminum Foil显示文摘The distribution of microelement Fe, Si, Cu and Mg in the surface layer of aluminum foil annealed at 300℃ and 500℃ were determined by secondary ion mass spectrometer. The corrosion structure produced by electrochemical etching was also observed. It was found that the Mg concentration at external surface was increased exponentially over the fourth degree and promoted by higher annealing temperature, which will increase the number of corrosion pits inside the large grains, and therefore the specific capacity of the foils for electrolytic capacitors. The similar effects of microelement Fe, Si and Cu were not so strong. | Weimin MAO, Heng JIANG, Ping YANG, Huiping FENG and Yongning YUDepartment of Materials, University of Science and Technology Beijing, Beijing 100083, ChinaProf., Ph.D., | 2005 | Journal of Materials Science & Technology2005，21，1： | 7 |
| 7 | Semi-solid slurry preparation and rolling of 1Cr18Ni9Ti stainless steel显示文摘The preparation and rolling of the semi-solid slurry 1Crl8Ni9Ti stainless steel were researched. The experimental results show that when stirred for 2-3 min under the given test condition, the semi-solid slurry with about 50%-60% (volume fraction) solid and the spherical primary austenitic grains in the size of 100-200 μm can be obtained, and it is easy to be discharged from the bottom little hole of the stirring chamber. The semi-solid slurry of 1Crl8Ni9Ti stainless steel can be rolled into the given plate successfully.However, the solid phase and liquid phase are easily separated in the rolling process, so that the solid primary austenitic grains are concentrated in the center and the liquid phase is near the edge of the rolled plate. The strengths of the plate rolled in the semi-solid state are higher than that of the traditionally repeated hot-rolled plate of 1Cr18Ni9Ti stainless steel. | Weimin Mao, Aimin Zhao, Dong Yun, Leping Zhang, and Xueyou ZhongMaterials Science and Engineering School, University of Science and Technology Beijing, Beijing 100083, China | 2003 | Journal of University of Science and Technology Beijing2003，10，6： | 6 |
| 8 | Clinicopathological analysis of metaplastic meningioma: report of 15 cases in Huashan Hospital显示文摘Objective: Metaplastic meningioma is a rare subtype of benign meningiomas, classified as WHO grade I with well prognosis. Here we presented our experiences on 15 cases of metaplastic meningioma, to investigate the clinicopathological features, therapies and prognosis of these cases. Methods: 15 patients underwent surgical treatment for intracranial metaplastic meningioma between 2001 and 2010 at Neurosurgery Department of Huashan Hospital, Shanghai, China. The clinical data, radiological manifestation, treatment strategy, pathological findings and prognosis of all patients were analyzed retrospectively. Results: Among the 15 cases (10 males and 5 females), the age ranged from 22 to 74 years old (the mean age was 50.67-year old). The clinical manifestations include headache, dizziness, seizure attack, vision decrease, and weakness of bilateral lower limbs. All the patients received surgical treatment, combined with radiotherapy in some cases. In the follow-up period, recurrence occurred in 2 cases, of which 1 patient died of other system complications. Conclusions: Metaplastic meningiomas are characterized by focal or widespread mesenchymal differentiation with formation of bone, cartilage, fat, and xanthomatous tissue elements. Surgical removal is the optimal therapy, and the overall prognosis is well. But recurrence may occur in some cases, thus radiotherapy is necessary for such kind of patients. | Hailiang Tang Huaping Sun Hong Chen Ye Gong Ying Mao Qing Xie Liqian Xie Mingzhe Zheng Daijun Wang Hongda Zhu Xiaoming Che Ping Zhong Kang Zheng Shiqi Li Weimin Bao Jianhong Zhu Xuanchun Wang Xiaoyuan Feng Xiancheng Chen Liangfu Zhou | 2013 | Chinese Journal of Cancer Research2013，25，1： | 6 |
| 9 | Influence of MnS particles on the behaviors of grain boundary migration in Fe-3%Si alloys显示文摘The precipitation behaviors of MnS particles at 900℃ in a hot deformed Fe-3%Si alloy were observed statistically. The ratio of MnS particles on dislocations and in grain boundaries was calculated based on a model concerning the second phase precipitation in supersaturated solid solution. It was indicated that the precipitation of MnS particles on dislocations prevailed. The coarsening process of MnS particles in grain boundaries determined the boundary mobility during the secondary recrystallization. However, the density difference of precipitated MnS particles inside the grains on both sides of a boundary will determine the migration direction of the boundary as well, besides the grain size effect. It was observed that the densities of MnS particles in two neighboring grains were commonly different, and the boundary tended to move towards the area with lower particle density. The factors, e.g. dislocation densities in differently oriented grains will affect the density of precipitated particles, in which the Goss grains with higher particle density could grow more easily. | MAO WeiMin AN ZhiGuo LI ShuXia | 2009 | Chinese Science Bulletin2009，54，23： | 5 |
| 10 | Filling ability of semi-solid A356 aluminum alloy slurry in rheo-diecasting显示文摘The effects of slurry temperature,injection pressure,and piston velocity on the rheo-filling ability of semisolid A356 al- loys were studied by the reho-diecasting methods.The results show that the slurry temperature of the semi-solid A356 aluminum al- loy has an important effect on the filling ability;the higher the slurry temperature,the better is the filling ability,and the appropriate slurry temperature for rheo-filling is in the range of 585-595℃.The injection pressure also has a great effect on the filling ability, and it is appropriate to the rheo-filling when the injection pressure is in the range of 15-25 MPa.The piston velocity also has a great effect on the filling ability,and it is appropriate to the rheo-filling when the piston velocity is in the range of 0.072-0.12 m/s.The filling ability of the slurry prepared by low superheat pouring with weak electromagnetic stirring is very good and the microstructural distribution in the rheo-formed die castings is homogeneous,which is advantageous to the high quality die casting. | Yuelong Bai Weimin Mao Songfu Gao Guoxing Tang Jun Xu | 2008 | Journal of University of Science and Technology Beijing2008，15，1： | 5 |
| 11 | Microstructure Characteristics and Apparent Viscosity of Hypereutectic Al-24%Si Alloy Melt During Semi-solid State Stirring显示文摘The microstructural evolution and apparent viscosity of hypereutectic Al-24%Si alloy during semi-solid state shearing were studied with a Searte type viscometer. When the alloy melt was continuously stirred from 720℃ to eutectic temperature, the primary Si crystals were gradually changed from elongated platelets to near-spherical shapes. It was found that some nondendritic a-phase formed when the melt was stirred below 585℃. The experiment showed that the semi-solid stirring had strong effect on inhibiting the anisotropic growth of Si crystals during solidification. The apparent viscosity of the alloy melt increased slowly with the decreasing of temperature before the formation of nondendritic α-phase, which caused the dramatic increase of apparent viscosity. | Yanjun Li, Weimin Mao, Zisheng Zhen, Xueyou Zhong (Material Science and Engineering School, University of Science and Technology Beijing, Beijing 100083, China) | 2001 | Journal of University of Science and Technology Beijing2001，8，2： | 4 |
| 12 | Rheological Behavior of Semi-Solid AZ91D Alloy显示文摘The rheological behavior and microstructure of semi-solid AZ91D was studied using a Couette type viscometer. The results show that the apparent viscosity of semi-solid AZ91D increases with the cooling rate increasing when it is continuously cooled and mechanically stirred and the empiric relation of the apparent viscosity with the cooling rate and solid fraction at shearing rate 93.7 s-1 is expressed as η=[0.66 - 0.63e(-ε/3.01)]e(fs/0.14), and with the shearing rate and solid fraction at cooling rate 4℃/min is shown as η=0.55e(fs/0.11-γ/87.59), as well as the cooling rate and shearing rate have an important effect on the microstructure of the semi-solid AZ91D alloy slurry, and decreasing the cooling rate and increasing the shearing rate are favorable to the nondendritic evolution of the primary grains. | Weimin MAO, Zisheng ZHEN, Shijian YAN and Xueyou ZHONGSchool of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China | 2004 | Journal of Materials Science & Technology2004，20，5： | 4 |
| 13 | Research on fractal characteristics of primary phase morphology in semi-solid A356 alloy显示文摘Semi-solid slurry of A356 alloy was prepared by low superheat pouring and slightly electromagnetic stirring,and the fractal characteristics of morphology in semi-solid primary phase was researched.The fractal dimensions of primary phase morphology in the semi-solid A356 alloy were calculated by the program written to calculate the fractal dimensions of box-counting in the image of solid phase morphology in semi-solid metal slurry.The results indicated that the morphology of primary phase in semi-solid A356 prepared by low superheat pouring and slightly electromagnetic stirring is characterized by fractal dimension,and the primary phase morphology obtained by the different processing parameters has different fractal dimensions.The morphology of primary phase at the different position of ingot has different fractal dimensions,which reflected the effect of solidified conditions at different positions in the same ingot on the morphology of semi-solid primary phase.Solidification of semi-solid alloy is a course of change in fractal dimension. | Zheng LIU Xiaomei LIU Chunhui HU Weimin MAO | 2009 | Acta Metallurgica Sinica(English Letters)2009，22，6： | 4 |
| 14 | Analysis of the Transformation-induced Plasticity Effect during the Dynamic Deformation of High-manganese Steel显示文摘The transformation-induced plasticity(TRIP) effect and resistance characteristics to adiabatic shear failure at high strain rates of high-manganese steel were investigated by using scanning electron microscopy and electron backscattering diffraction. Results showed that the high-manganese steel exhibited excellent strain hardening effect and resistance to adiabatic shear failure because of the TRIP effect. The TRIP effect occurred during dynamic deformation and showed two distinct stages,namely,the smooth TRIP process before the formation of adiabatic shear band(ASB) and the inhibited TRIP process during further deformation. In the first stage,the martensitic transformation showed slight orientation dependence and weak variant selection,which promoted the TRIP effect. In the second stage,reverse martensitic transformation occurred. Adiabatic shear bands(ASBs) developed typical shear microtextures {111}<110>. In microtextures,two groups of fine grains are in a twin relationship and uniform distribution,which restrained the formation of holes and cracks within the ASBs and enhanced damage resistance after ASB formation. | Huizhen Wang Xiurong Sun Ping Yang Weimin Mao Li Meng | 2015 | Journal of Materials Science & Technology2015，31，2： | 4 |
| 15 | On the Taylor principles for plastic deformation of polycrystalline metals显示文摘 | Weimin MAO | 2016 | Frontiers of Materials Science2016，10，4： | 4 |
| 16 | Effect of pouring temperature on semi-solid slurry of ZL101 alloy prepared by slightly electromagnetic stirring显示文摘The semi-solid slurry of ZL101 alloy is prepared by a combination technology of low superheat pouring and slightly electromagnetic stirring.The effects of pouring temperature on the slurry prepared by the technology are investigated.The results indicate that it is feasible to prepare the slurry with globular primary phases by low superheat pouring and slightly electromagnetic stirring,and that the pouring temperature has an important effect on the morphology and the size of primaryα-Al in ZL101 alloy.By applying suitable slightly electromagnetic stirring combining with relatively increased pouring temperature,i.e.,in a practical way to apply low superheat pouring technology,is capable of obtaining appropriate semi-solid slurry of ZL101 alloy with globular shape of primary phase.Compared with the samples made by low superheat pouring only without stirring,the samples prepared by applying both slightly electromagnetic stirring and low superheat pouring can enable to achieve the same grain size and morphology of the primary phase with that of pouring at 15-35℃higher. | Liu Zheng Mao Weimin | 2009 | China Foundry2009，6，1： | 4 |
| 17 | Preparation of semi-solid AlSi7Mg alloy slurry with big capability显示文摘Semi-solid AlSi7Mg alloy slurry was prepared by low superheat pouring and weak traveling-wave electromagnetic stirring.The effects of pouring temperature and stirring power on the microstructure of AlSi7Mg alloy slurry were studied.The results show that the semi-solid AlSi7Mg alloy slurry of 5 kg can be prepared.This new technology can save energy and make the pouring process convenient.When the pouring temperature is decreased at a stirring power of 0.41 kW,the shape of primary α-Al grains gradually changes from dendritic-like to spherical.When the alloy melt is poured at the temperature(630°C) with a certain superheat,the pouring process becomes easier,and the spherical microstructure of AlSi7Mg alloy slurry can be prepared by the weak traveling-wave electromagnetic stirring.When the pouring temperature is 630°C,increasing the stirring power appropriately can result in better spherical primary α-Al grains,but if the stirring power is increased to a certain value(1.72 kW),the shape of primary α-Al grains does not obviously improve when the stirring power is continually increased. | LI Sha and MAO Weimin School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China | 2010 | Rare Metals2010，29，6： | 4 |
| 18 | TEXTURE IN INHOMOGENEOUSLY ROLLED ALUMINIUM SHEET显示文摘The changs of stress state in cold rolled aluminium sheet with large pass reduction,the combining activation process of slip systems as well as the formation mechanism of corresponding shear textures were investigated.It is shown that the rolling deformation with large pass reduction produces not only the general rolling stresses but also a strong shear stress in aluminium sheet.With increasing additional shear stress the general rolling textures,i.e.{112}<111>,{123}<634>,{110}<1I2>and{110}<001>decrease,and the shear texture,i.e.{001}<110>as well as{111}fibre texture become stronger.The internal relation of these two kinds of textures was also discussed. | Mao Weimin | 1992 | Transactions of Nonferrous Metals Society of China1992，2，1： | 3 |
| 19 | Semi-solid A356 alloy slurry for rheocasting prepared by a new process显示文摘To obtain the semi-solid slurry with uniform and fine structure morphology that satisfies the requirement of rheocasting process, a new process for preparing semi-solid Al alloy slurry was developed, in which local chilling was combined with low superheat pouring and slight electromagnetic stirring (LSPSEMS). The morphology and the size of primary α-Al in the A356 alloy slurry prepared with the new process, i.e., LSPSEMS with local chilling, were investigated using MIAPS image analyzing software, and the grain refinement mechanism was discussed. The results indicate that the semi-solid primary phase consists of particle-like or globular-like α-Al, and the morphology and grain size of primary α-Al in the slurry can be markedly improved by the new process. The fine primary α-Al distributes uniformly in the slurry, which satisfies the requirement of rheocasting. Compared with the alloy prepared by LSPSEMS, the average equal-area-circle grain diameter of primary α-Al in semi-solid A356 alloy ingot prepared by the new process is decreased from 85.6 μm to 68.8 μm at the central area, 112.6 μm to 77.6 μm at the transition area and is 84.7 μm in the edge area, respectively. The corresponding shape factor of primary α-Al is increased from 0.78 to 0.83, 0.54 to 0.77 and 0.28 to 0.59, respectively. In addition, the pouring temperature could be suitably raised from 620-630 ℃ of the traditional process to 650 ℃ using this technique, which is convenient for practical operation. The mechanism of grain refinement, in the new process, is that the local chilling quickens up the temperature decrease in the center of the melt. The nuclei could not grow up in a short time so the finer grains are formed in the melt. | Liu Zheng Liu Xiaomei Mao Weimin | 2013 | China Foundry2013，10，3： | 3 |
| 20 | Rheological behavior of semi-solid 7075 aluminum alloy at steady state显示文摘The further application of semi-solid processing lies in the in-depth fundamental study like rheological behavior. In this research, the apparent viscosity of the semi-solid slurry of 7075 alloy was measured using a Couette type viscometer. The effects of solid fraction and shearing rate on the apparent viscosity of this alloy were investigated under different processing conditions. It can be seen that the apparent viscosity increases with an increase in the solid fraction from 10% to 50%(temperature 620 oC to 630 oC) at steady state. When the solid fraction was fi xed, the apparent viscosity can be decreased by altering the shearing rate from 61.235 s-1 to 489.88 s-1 at steady state. An empirical equation that shows the effects of solid fraction and shearing rate on the apparent viscosity is fi tted:. The microstructure of quenched samples was examined to understand the alloy's rheological behavior. | Li Yageng Mao Weimin Zhu Wenzhi Yang Bin | 2014 | China Foundry2014，11，2： | 3 |
您所在的机构暂未开通此部分的功能，请联系管理员