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Effect of mixing temperature on microstructure of an Al-Si alloy prepared by controlled diffusion solidification 被引量:1
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作者 Han Xue Ti-jun Chen +3 位作者 Xue-zheng Zhang Guang-li Bi Ying Ma Ren-guo Guan 《China Foundry》 SCIE CAS CSCD 2023年第3期241-252,共12页
The effects of mixing temperature,i.e.,the temperatures of two precursor melts(pure Al and Al-12Si),on the temperature and solute fields of resultant mixture,the nucleation and growth,and the size and morphology of pr... The effects of mixing temperature,i.e.,the temperatures of two precursor melts(pure Al and Al-12Si),on the temperature and solute fields of resultant mixture,the nucleation and growth,and the size and morphology of primary grains during controlled diffusion solidification(CDS) of Al-8Si alloy were investigated by using simulation and calculation.The results indicate that a lower mixing temperature is helpful for achieving more supercooled microscale Al-rich pockets in the mixture,and increasing the width and supercooling degree of supercooling zone in the Al-rich pockets,and thus,the nucleation rate.The nuclei grow up in nondendritic mode,resulting in spheroidal,at least,nondendritic grains.In a successful CDS,the superheat degrees of the two precursor melts should be limited within several degrees,and it is not necessary to extra stipulate the superheat degree of target alloy melt(Al-8Si) when the requirement about Gibbs energies of the three melts is matched.Subsequent observation on casting microstructures shows that the employed simulation and calculation processes are reasonable and the achieved results are reliable. 展开更多
关键词 controlled diffusion solidification al-si alloy nucleation and growth SUPERCOOLING nondendritic grains
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Simulation on microstructure evolution of Al-Si alloy under effect of natural convection during solidification 被引量:5
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作者 Zhen-hong WANG Li-tong ZHANG +1 位作者 Bin SU Xiao-peng ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第1期79-90,共12页
The solidification microstructure of Al-Si alloy was observed in the experiment,the second dendrite arm spacing(SDAS)was measured,and the effect of temperature on the microstructure was analyzed.Phase-field(PF)model i... The solidification microstructure of Al-Si alloy was observed in the experiment,the second dendrite arm spacing(SDAS)was measured,and the effect of temperature on the microstructure was analyzed.Phase-field(PF)model incorporating natural convection caused by gravity was employed to simulate the microstructure evolution of Al-Si alloy under the experimental conditions.Good agreements between the experimental and simulation results verified the reliability of the simulation approach proposed in this study.Based on the proposed model,a series of simulation cases(2D and 3D)were performed to investigate the evolution of columnar and equiaxed dendritic structures.It was found that the solute content of the alloy had little impact on the microstructure evolution,while the solute expansion coefficient had obvious effect on the dendrite tip velocities.Significant improvement of computational efficiency was achieved via novel algorithms,making it possible to perform massive simulation for studying the evolution of solidification microstructures,which is hard to be directly observed in experiments via synchrotron radiation for Al-Si alloy. 展开更多
关键词 al-si alloy solidification microstructure natural convection phase-field simulation
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Study on Improving Solidification Structure of Rare Earth Al-Si Alloys with Electropulse Acting on Liquid Alloy
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作者 Cui Heng Cang Daqiang Zong Yanbing Li Lingzhen He Peng Mo Zhiying 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第z1期49-52,共4页
Electropulse modification (EPM) process, a new physical field method for improving the solidification structure of metals was introduced.Different from other research, EPM is only acting pulse current on melt under li... Electropulse modification (EPM) process, a new physical field method for improving the solidification structure of metals was introduced.Different from other research, EPM is only acting pulse current on melt under liquid state.The solidification structure of Al-Si alloys, A1-Cu alloys,cast iron and steel can be modified obviously with this method: the solidification structure of ZL101 alloy presented the Na and Sr modification and the mechanical properties were enhanced; a large number of primary silicon appeared in the microstructure of ZL109 alloy; the equiaxed grain zone was expanded and the grains were fined in Al-5.0wt% Cu alloy; the graphitization took place in solidification process of molten cast iron; the grain sizes of solidification structure of T8 steel were reduced significantly and the shape of steel pearlites also changed; the equiaxed grain zone increased to 88% from original untreated 19%, the equiaxed grains were fined and the intercrystalline crack was avoided in concasting billet by continuously treating liquid electrical sheet steel in tundish.Effects of rare earths on casting Al-Si alloys were also summarized.The method of modifying the solidification structure of rare earth Al-Si alloys with EPM in producing the alloys was proposed. 展开更多
关键词 electropulse modification al-si alloy solidification structure RAre earths
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Functions and mechanism of modification elements in eutectic solidification of Al-Si alloys:A brief review 被引量:6
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作者 Zu Fangqiu Li Xiaoyun 《China Foundry》 SCIE CAS 2014年第4期287-295,共9页
Being used more and more widely in engineering,AlSi alloys comprise about 80%of all kinds of aluminum alloys,which are the most widely utilized nonferrous alloys.Although most Al-Si alloys consist of multiple componen... Being used more and more widely in engineering,AlSi alloys comprise about 80%of all kinds of aluminum alloys,which are the most widely utilized nonferrous alloys.Although most Al-Si alloys consist of multiple components,the eutectics in the structure accounts for 50%-90%of the sum volume of such alloys.Therefore,understanding the modification mechanism and function rules of the AlSi eutectic solidification is the technical key in controlling the structures and properties of such casting alloys.The present paper chiefly reviews recent investigation developments and important conclusions along the lines of the functions of modification elements and their modification mechanism in the eutectic solidification of Al-Si alloys. 展开更多
关键词 al-si alloys eutectic solidification MODIFICATION silicon morphology growth kinetics
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Solidification structure of eutectic Al-Si alloy under a high magnetic field-aid-electromagnetic vibration 被引量:4
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作者 Jianbo YU Zhongming REN Weili REN Kang DENG Yunbo ZHONG 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2009年第3期191-196,共6页
An electromagnetic vibration was generated by simultaneously imposing a strong static magnetic field (up to 10 T) and an alternative electricity current to the metal. Its effects on the solidification structure of e... An electromagnetic vibration was generated by simultaneously imposing a strong static magnetic field (up to 10 T) and an alternative electricity current to the metal. Its effects on the solidification structure of eutectic Al-Si alloy have been investigated experimentally. It is found that the eutectic structure has been refined by solely imposing high magnetic field while it is coarsened under the electromagnetic vibration. Furthermore, polyhedral Si grains and non-dendritic α-Al appeared when the electromagnetic vibration strength was strong enough. The refining of eutectic structure is attributed to the decrease of diffusion coefficient caused by the strong magnetic field. The coarseness of eutectic structure may be attributed to the convection caused by electromagnetic vibration. Strong convection may break co-operative growth of eutectic phases to form polyhedral Si grains and non-dendritic α-Al. 展开更多
关键词 Strong magnetic field Electromagnetic vibration Eutectic solidification Polyhedral Si al-si alloy
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Research on semi-solid slurry of a hypoeutectic Al-Si alloy prepared by low superheat pouring and weak electromagnetic stirring 被引量:21
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作者 LIU Zheng MAO Weiming ZHAO Zhengduo 《Rare Metals》 SCIE EI CAS CSCD 2006年第2期177-183,共7页
The semi-solid slurry of a hypoeutectic Al-Si alloy was manufactured by low superheat pouring and weak electromagnetic stirring. The effects of pouting temperature and stirring power on the semi-solid slurry were inve... The semi-solid slurry of a hypoeutectic Al-Si alloy was manufactured by low superheat pouring and weak electromagnetic stirring. The effects of pouting temperature and stirring power on the semi-solid slurry were investigated. The results indicated that the semi-solid slurry to satisfy rheocasting can be manufactured by low superheat pouring and weak electromagnetic stirring. The pouring temperature (or superheat) and the stirring power remarkably affected the morphology of primary α-Al and the size of primary α-Al, and there is no obvious effect of stirring time on primary α-Al. Compared with the samples made by low superheat pouring with no stirring, the nucleation rate, particle morphology and grain size of primary α-Al in A356 were markedly improved by low superheat pouring and weak electromagnetic stirring. On the condition of weak electromagnetic stirring, the pouring temperature with low superheat can be suitably raised to reach the effectiveness obtained from the lower pouring temperature without stirring. 展开更多
关键词 semi-solid low superheat pouring weak electromagnetic stirring hypoeutectic al-si alloy A356 Al alloy
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Manufacture technique of semi-solid slurry of hypoeutectic Al-Si alloy by low superheat pouring and weak electromagnetic stirring 被引量:11
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作者 LIU Zheng MAO Wei-ming ZHAO Zheng-duo 《China Foundry》 SCIE CAS 2006年第2期102-107,共6页
The semi-solid slurry of hypoeutectic Al-Si alloy was manufactured by low superheat pouring and weak electromagnetic stirring. The effects of pouring temperature and stirring power on the semi-solid slurry making proc... The semi-solid slurry of hypoeutectic Al-Si alloy was manufactured by low superheat pouring and weak electromagnetic stirring. The effects of pouring temperature and stirring power on the semi-solid slurry making process were investigated. The results indicate that the semi-solid slurry to satisfy rheocasting requirement can be made by a combination of low superheat pouring and weak electromagnetic stirring. The pouring temperature (or superheat) and the stirring power significantly affect the morphology and the size of primary α-Al, while there is no obvious effect of the stirring time on primary α-Al. Compared with the samples made by low superheat pouring without stirring, the nucleation rate, particle morphology and grain size of primary α-Al in A356 Al alloy are markedly improved by a process of applying both low superheat pouring and weak electromagnetic stirring. Under the condition of weak electromagnetic stirring applied, the pouring temperature with low superheat can be equivalently to reach the effectiveness obtained from the even lower pouring temperature without stirring. 展开更多
关键词 semi-solid low SUPERHEAT POURING weak electromagnetic STIRRING HYPOEUTECTIC al-si alloy A356 Al alloy
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In-situ observation of porosity formation during directional solidification of Al-Si casting alloys 被引量:3
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作者 Zhao Lei Liao Hengcheng +2 位作者 Pan Ye Wang Qigui Sun Guoxiong 《China Foundry》 SCIE CAS 2011年第1期14-18,共5页
In-situ observation of porosity formation during directional solidification of two Al-Si alloys (7%Si and 13%Si) was made by using of micro-focus X-ray imaging.In both alloys,small spherical pores initially form in th... In-situ observation of porosity formation during directional solidification of two Al-Si alloys (7%Si and 13%Si) was made by using of micro-focus X-ray imaging.In both alloys,small spherical pores initially form in the melt far away from the eutectic solid-liquid (S/L) interface and then grow and coagulate during solidification.Some pores can float and escape from the solidifying melt front at a relatively high velocity.At the end of solidification,the remaining pores maintain spherical morphology in the near eutectic alloy but become irregular in the hypoeutectic alloy.This is attributed to different solidification modes and aluminum dendrite interactions between the two alloys.The mechanism of the porosity formation is briefly discussed in this paper. 展开更多
关键词 in-situ observation porosity formation al-si casting alloy micro-focus X-ray directional solidification
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Effect of mixing rate and temperature on primary Si phase of hypereutectic Al-20Si alloy during control ed diffusion solidification(CDS) process 被引量:5
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作者 Yuan-dong Li Xin-long Zhang +3 位作者 Ying Ma Diran Apelian Hong-wei Zhou Xing-hai Liu 《China Foundry》 SCIE CAS 2015年第3期173-179,共7页
Controlled Diffusion Solidification(CDS) is a promising process relied on mixing two liquid alloys of precisely controlled chemistry and temperature in order to produce a predetermined alloy composition. In this study... Controlled Diffusion Solidification(CDS) is a promising process relied on mixing two liquid alloys of precisely controlled chemistry and temperature in order to produce a predetermined alloy composition. In this study, the CDS was employed to prepare hypereutectic Al-20%Si(mass fraction) alloy using Al-30%Si and pure Al of different temperatures. The mixing rate was controlled using three small crucibles with a hole of different diameters in their bottom. The effect of mixing rate and temperature on the microstructure of the primary Si-phase during the mixing of molten Al and Al-30%Si was studied. The results showed that when the diameter of the small crucible bottom hole is 16 mm, a higher mass mixing rate 0.217 kg·s-1 would results in a lower stream velocity 0.414 m·s-1. Conversely a lower mass mixing rate 0.114 kg·s-1(the diameter of the small crucible bottom hole is 8 mm) would result in a higher fluid stream velocity 0.879 m·s-1. A lower mass mixing rate would be better to refine the primary Si than a higher mass mixing rate. Meanwhile, the morphology and distribution of primary Si could also be improved. Especially, when Al-30%Si alloy at 820 °C was mixed with pure Al at 670 °C in the case of a mass mixing rate of 0.114 kg·s-1 and a pouring temperature of 680 °C, the average size of the primary Si phase would be only 18.2 μm. Its morphology would mostly be octahedral and the primary Si would distribute uniformly in the matrix microstructure. The lower mass mixing rate(0.114 kg·s-1) will enhance the broken tendency of Al-30%Si steam and the mixing agitation of resultant melt, so the primary Si phase can be better refined. 展开更多
关键词 Controlled Diffusion solidification(CDS) hypereutectic al-si alloy mass mixing rate stream velocity primary Si
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Microstructure and high temperature tensile properties of Al-Si-Cu-Mn-Fe alloys prepared by semi-solid thixoforming 被引量:2
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作者 Bo LIN Tao FAN +3 位作者 Hao-yu LI Yu-liang ZHAO Wei-wen ZHANG Kun LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第8期2232-2249,共18页
The differences in the microstructure and elevated temperature tensile properties of gravity die cast,squeeze cast,and semi-solid thixoformed Al-Si-Cu-Mn-Fe alloys after thermal exposure at 300℃were discussed.The res... The differences in the microstructure and elevated temperature tensile properties of gravity die cast,squeeze cast,and semi-solid thixoformed Al-Si-Cu-Mn-Fe alloys after thermal exposure at 300℃were discussed.The results demonstrate that the elevated temperature tensile properties of semi-solid thixoformed alloys were significantly higher than those of gravity die cast and squeeze cast alloys,especially after thermal exposure for 100 h.The ultimate tensile strength(UTS)of semi-solid thixoformed alloys after thermal exposure at 300℃for 0.5,10 and 100 h were 181,122 and 110 MPa,respectively.The UTS values of semi-solid thixoformed alloys were higher than those of heat resistant aluminum alloys used in commercial applications.The enhanced elevated temperature tensile properties of semi-solid thixoformed experimental alloys after thermal exposure can be attributed to the combined reinforcement of precipitation strengthening and grain boundary strengthening due to thermally stable intermetallic phases as well as suitable grain size. 展开更多
关键词 al-si alloys iron-rich intermetallics semi-solid thixoforming MICROSTRUCTUre tensile properties thermal exposure
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Influence of Al-B grain refiner on porosity formation of directionally solidified Al-Si alloys 被引量:1
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作者 Muhammet Uludağ 《China Foundry》 SCIE 2020年第5期372-377,共6页
This work aims to present a perspective for porosity formation in three different alloys:A356,A413 and A380.1 by taking into account the addition of Al-B grain refiners:AlTi5B1 and Al3B.The directional solidification ... This work aims to present a perspective for porosity formation in three different alloys:A356,A413 and A380.1 by taking into account the addition of Al-B grain refiners:AlTi5B1 and Al3B.The directional solidification method was used,and microstructural changes of the alloys and its correlation with porosity formation were investigated.Pore size,number of pores,average pore length and distribution of pores were statistically analyzed.Also,external shrinkage was examined,and the volume of external shrinkage was calculated.It was found that there was a relationship between external shrinkage and the size and number of pores.As the size and number of pores internally decrease,external shrinkage increases.Additionally,porosity is decreased in all the three Al-Si alloys when Al-B grain refiners are used.The distribution of pore diameters is low when AlTi5B1 is used.Grain refiners have a different effect on porosity formation of Al-Si alloys with regard to their solidification morphology. 展开更多
关键词 al-si alloys directional solidification grain refinement internal porosity external shrinkage
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Effect of electric pulse treatment on solidification structure of an Al-15%Si alloy 被引量:6
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作者 SHI Xiangdong WANG Jingsong +3 位作者 XUE Qingguo CANG Daqiang WANG Liping WU Shupiao 《Rare Metals》 SCIE EI CAS CSCD 2005年第3期288-292,共5页
The effect of electric pulse modifying on the solidification structure of an Al-15%Si alloy was investigated. The result shows that the primary silicon disappears sometimes and the eutectic phase is refined after the ... The effect of electric pulse modifying on the solidification structure of an Al-15%Si alloy was investigated. The result shows that the primary silicon disappears sometimes and the eutectic phase is refined after the treatrnent of EP (electric pulse) though there are different modalities in different treating durations. DSC (differential scanning calorimetry) analysis indicates that the super-cooling texture decreases and the freezing range narrows evidently after the electric pulse treatment. 展开更多
关键词 solidification structure electric pulse al-si alloy DSC
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Physical Properties and Solidification Structure of Al-SiEutectic Alloy Melt with Cerium Modification 被引量:1
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作者 李培杰 郭景杰 +1 位作者 贾均 李庆春 《Journal of Rare Earths》 SCIE EI CAS CSCD 1996年第2期140-144,共5页
Relationship between physical property change of melt and solidification structure has been investigated by measuring the density, viscosity and electrical resistivity of the Al-Si eutectic alloy melt with different C... Relationship between physical property change of melt and solidification structure has been investigated by measuring the density, viscosity and electrical resistivity of the Al-Si eutectic alloy melt with different Ce contents. The results show that there exists corresponding relation between the turning points of physical properties change and eutectic Si shape change. 展开更多
关键词 Melt physical properties al-si alloy Ce solidification structure
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Overflowing phenomenon during ultrasonic treatment in Al-Si alloys 被引量:3
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作者 张宇博 卢一平 +3 位作者 接金川 傅莹 钟德水 李廷举 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3242-3248,共7页
At the late stage of solidification with ultrasonic treatment (UST) in Al-Si alloys, a part of semisolid overflows and climbs along the probe. The interesting phenomenon and its influence on the solidification micro... At the late stage of solidification with ultrasonic treatment (UST) in Al-Si alloys, a part of semisolid overflows and climbs along the probe. The interesting phenomenon and its influence on the solidification microstructure were investigated in order to better study the mechanism of UST. It is considered that the overflowing phenomenon occurs due to the changes of vibration and flow in the remaining semisolid. Because the overflowed portion comes from the region with intense UST effect and vibrates with the probe during solidification, great modification of primary and euteetic Si (about 10 pm in length) and refinement of primary a(Al) (about 70 μm in size) are observed in this portion. 展开更多
关键词 al-si alloy ultrasonic treatment overflowing phenomenon solidification microstructure
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Effect of phosphor addition on eutectic solidification and microstructure of an Al-13%Si alloy
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作者 Liao Hengcheng Zhao Lei Xi Xiao 《China Foundry》 SCIE CAS 2011年第4期418-423,共6页
As the refiner or modifier, the master alloys containing high concentration phosphor are widely used in preparing eutectic or hypereutectic Al-Si alloys. To study the effect of phosphor addition on the eutectic solidi... As the refiner or modifier, the master alloys containing high concentration phosphor are widely used in preparing eutectic or hypereutectic Al-Si alloys. To study the effect of phosphor addition on the eutectic solidification and microstructure of the Al-13%Si alloy, an investigation has been undertaken by means of thermal analysis and micro/macro-structure observation. Results indicate that addition of phosphor in near eutectic Al-Si alloy promotes the nucleation of eutectic but has little refinement impact on primary Si particles as expected. Conversely, both primary Si particles and eutectic Si flakes become slightly coarser in P-rich alloys. The coarsening of eutectic Si flakes ties closely to the increased eutectic growth temperature with phosphor addition. The eutectic solidification of the alloy proceeds from the near mold zone towards the center, and it is also found that a few independent nucleation regions emerge in liquid at the solidification front due to the addition of phosphor. 展开更多
关键词 al-si alloy eutectic solidification MICROSTRUCTUre thermal analysis PHOSPHOR
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EFFECT OF Ti ON MICROSTRUCTURE OF RAPIDLY SOLIDIFIED Al-Si ALLOYS
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作者 SHAO Guosheng SHEN Ningfu Zhengzhou Institute of Technology,Zhengzhou,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1992年第4期292-296,共5页
An addition of Ti as alloying element to Al-Si binary alloy will reduce the undercooling-abili- ty on rapid solidification of the melt-spun ribbon.The microstructure will be encoarsened even at initiation of its solid... An addition of Ti as alloying element to Al-Si binary alloy will reduce the undercooling-abili- ty on rapid solidification of the melt-spun ribbon.The microstructure will be encoarsened even at initiation of its solidification,so as to aggravate the eellular segregation of Si in the alloy ribbon. 展开更多
关键词 rapid solidification TI al-si alloy STRUCTUre
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Microstructure variation and growth mechanism of hypoeutectic Al-Si alloy solidifi ed under high pressure
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作者 Zhang Guozhi Yu Xifeng Liu Xinggang 《China Foundry》 SCIE CAS 2009年第2期129-132,共4页
The microstructure of hypoeutectic Al-9.21wt.%Si alloy solidified under 5.5 GPa was studied. The results show that the solidification microstructure is refined. The primary a phase is the extended solid solution. The ... The microstructure of hypoeutectic Al-9.21wt.%Si alloy solidified under 5.5 GPa was studied. The results show that the solidification microstructure is refined. The primary a phase is the extended solid solution. The solid solubility of Si in α phase is up to 8.26wt.%. The growth mode of the α phase is cellular, and this cellular growth mechanism is interpreted in terms of the decrease of the diffusivity and the extended solid solution under high pressure. By calculation, it can be known that the the diffusivity of solute in the liquid under normal pressure is as high as two hundred times that under high pressure. The microhardness of the hypoeutectic Al-Si alloy solidified under high pressure is higher than that of solidified under normal pressure. After annealing, Si precipitates from the solid solution, the microhardness of the alloy decrease, but, still higher than that of solidified under normal pressure. 展开更多
关键词 al-si alloy high pressure solidification extended solid solution cellular growth
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Microstructure Characteristics and Apparent Viscosity of Hypereutectic Al-24%Si Alloy Melt During Semi-solid State Stirring 被引量:4
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作者 Yanjun Li, Weimin Mao, Zisheng Zhen, Xueyou Zhong (Material Science and Engineering School, University of Science and Technology Beijing, Beijing 100083, China) 《Journal of University of Science and Technology Beijing》 CSCD 2001年第2期126-128,共3页
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 d... 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 degreesC 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 degreesC. 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 alpha -phase, which caused the dramatic increase of apparent viscosity. 展开更多
关键词 hypereutectic al-si alloy solidification structures apparent viscosity
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Si-RICH LAYER FORMATION DURING DIRECTIONAL SOLIDIFICATION OF AI-Si EUTECTIC ALLOY IN ELECTROMAGNETIC FIELD
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作者 REN Zhongming SU Hui JIN Junze Dalian University of Technology,Dalian,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1991年第8期147-149,共3页
The formation of a special Si-rich layer on the periphery of Al-Si eutectic alloy specimen during directional solidification in rotary electromagnetic field has been investigated.This layer seems due to the migration ... The formation of a special Si-rich layer on the periphery of Al-Si eutectic alloy specimen during directional solidification in rotary electromagnetic field has been investigated.This layer seems due to the migration of some Si grains onto the crucible wall,then stagnating and coarsening further. 展开更多
关键词 al-si eutectic alloy directional solidification
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Effect of pre-annealing on microstructure and compactibility of gas-atomized Al-Si alloy powders
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作者 蔡志勇 张纯 +3 位作者 王日初 彭超群 邱科 王乃光 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第9期2355-2362,共8页
Effect of pre-annealing treatment temperature on compactibility of gas-atomized Al-27%Si alloy powders was investigated. Microstructure and hardness of the annealed powders were characterized. Pre-annealing results in... Effect of pre-annealing treatment temperature on compactibility of gas-atomized Al-27%Si alloy powders was investigated. Microstructure and hardness of the annealed powders were characterized. Pre-annealing results in decreasing Al matrix hardness, dissolving of needle-like eutectic Si phase, precipitation and growth of supersaturated Si atoms, and spheroidisation of primary Si phase. Compactibility of the alloy powders is gradually improved with increasing the annealing temperature to 400 ℃. However, it decreases when the temperature is above 400 ℃ owing to the existence of Si-Si phase clusters and the densely distributed Si particles. A maximum relative density of 96.1% is obtained after annealing at 400 ℃ for 4 h. In addition, the deviation of compactibility among the pre-annealed powders reaches a maximum at a pressure of 175 MPa. Therefore, a proper pre-annealing treatment can significantly enhance the cold compactibility of gas-atomized Al-Si alloy powders. 展开更多
关键词 al-si alloy COMPACTIBILITY rapid solidification annealing MICROSTRUCTUre
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