Refinement of primary Si in hypereutectic Al–Si alloy by electromagnetic stirring

Lu, Dehong; Jiang, Yehua; Gui-sheng, Guan; Zhou, Rongfeng; Li, Zhenhua; Zhou, Rong

doi:10.1016/j.jmatprotec.2006.12.008

Cited by 128 publications

(53 citation statements)

References 11 publications

(13 reference statements)

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“…The aluminum metal matrix composite materials are the combination of two or more constituents in which one is matrix and other is reinforcement [1][2][3]. If the casting processes of the melted metal are applied directly in the state of melted Al matrix with reinforcement, the reinforced metal matrix composite parts with the complicated shape can be produced.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Microstructure and Mechanical Properties of A356/SiC Metal Matrix Composites Produced by Two Different Melting Routes

Dwivedi

Sharma

Mishra

2014

International Journal of Manufacturing Engineering

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A356/SiC metal matrix composites with different weight percent of SiC particles were fabricated by two different techniques such as mechanical stir casting and electromagnetic stir casting. The results of macrostructure, microstructure, and XRD study revealed uniform distribution, grain refinement, and low porosity in electromagnetic stir casing samples. The mechanical results showed that the addition of SiC particles led to the improvement in tensile strength, hardness, toughness, and fatigue life. It indicates that type of fabrication process and percentage of reinforcement are the effective factors influencing the mechanical properties. It is observed that when percentage of reinforcement increases in electromagnetic stir casting, best mechanical properties are obtained.

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Section: Introductionmentioning

confidence: 99%

Comparison of Microstructure and Mechanical Properties of A356/SiC Metal Matrix Composites Produced by Two Different Melting Routes

Dwivedi

Sharma

Mishra

2014

International Journal of Manufacturing Engineering

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“…In addition, the cooling curve, superheating and hardness of the alloy were also analyzed. mechanical/electromagnetic stirring treatment [13][14][15] . …”

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confidence: 99%

Effect of phosphorus and heat treatment on microstructure of Al-25%Si alloy

Dang

Jian

et al. 2017

China Foundry

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T he hypereutectic Al-Si alloys play an important role in the fields of automotive and aerospace industries due to their excellent casting ability, low thermal expansion coefficient and high wear resistance [1][2][3] . The microstructure evolution of hypereutectic Al-Si alloy is mainly divided into two stages during solidification: the precipitation of primary silicon and subsequent eutectic transformation. The morphology and distribution of silicon affect the mechanical properties and application scope of the alloys. For hypereutectic Al-Si alloys, the coarse primary silicon may easily produce stress concentration, form the crack and accelerate the crack growth. To gain better mechanical properties, modification treatment and heat treatment are carried out for hypereutectic Al-Si alloys to change the morphology, size and distribution of silicon phase. Modification treatment can significantly improve the morphology and distribution of silicon [4][5][6][7][8][9] . Heat treatment aims at acquisitions of supersaturated solution, high density vacancies and spheroidization of eutectic Si. Many researchers have focused on the improvement of modifiers to meet the requirements of environmental protection and industry applications. The common methods of modification are chemical treatment by modifiers [5][6][7][8][9] , melt thermal treatment [10][11][12] and Abstract: It is known that phosphorus can refine the primary silicon and heat treatment can spheroidize the eutectic silicon. This paper presents an optimal combination of heat treatment processes and P refinement on hypereutectic Al-Si alloy. The optimal P addition amount, and the solution and aging temperatures for Al-25%Si alloy were obtained through the orthogonal experiment, and their modification effects were discussed. The results show that P addition has the greatest modification effect, followed by aging temperature, and the modification effect of solution temperature is the least. The optimized modification parameters are: addition of 0.6% P, solution at 540 ºC and aging at 160 ºC . In addition, the cooling curve, superheating and hardness of the alloy were also analyzed. mechanical/electromagnetic stirring treatment [13][14][15] . Key words:Refinement by element addition has been widely applied in traditional casting Al-Si alloy due to simplicity and validity [4][5][6][7][8][9] . P is one of the most effective modifiers and refiners of primary Si particles and can be added into the melt as master alloys, such as Si-P [5] , Cu-P [6] , Al-P [7] , Al-Si-P [8] and Al-Zr-P [9] . Adding P to Al-Si hypereutectic alloy can reduce the size of primary Si particles by the active nuclei sites [16] . Wu Yaping found the best modification effect can be achieved when Si-P master alloy is added into Al melt before the addition of silicon instead of directly adding into Al-24%Si alloy melt, because AlP can form after adding the Si-P into Al melt which can act as the nuclei of primary Si phases during the solidification process. The optimized modification parameters were mo...

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“…Physical approaches to the refinement of primary Si, including ultrasound [5,6], electromagnetic stirring [7] and electromagnetic vibration [8] have been attempted with limited success. Treatments are localised within the melt and take of the order of ten minutes even within very small quantities of liquid.…”

Section: Introductionmentioning

confidence: 99%

Refinement of primary Si in hypereutectic Al-Si alloys by intensive melt shearing

Zhang¹,

Li²,

Stone³

et al. 2012

IOP Conf. Ser.: Mater. Sci. Eng.

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Abstract. Hypereutectic Al-Si based alloys are gaining popularity for applications where a combination of light weight and high wear resistance is required. The high wear resistance arising from the hard primary Si particles comes at the price of extremely poor machine tool life. To minimize machining problems while exploiting outstanding wear resistance, the primary Si particles must be controlled to a uniform small size and uniform spatial distribution. The current industrial means of refining primary Si chemically by the addition of phosphorous suffers from a number of problems. In the present paper an alternative, physical means of refining primary Si by intensive shearing of the melt prior to casting is investigated. Al-15wt%Si alloy has been solidified under varying casting conditions (cooling rate) and the resulting microstructures have been studied using microscopy and quantitative image analysis. Primary Si particles were finer, more compact in shape and more numerous with increasing cooling rate. Intensive melt shearing led to greater refinement and more enhanced nucleation of primary Si than was achieved by adding phosphorous. The mechanism of enhanced nucleation is discussed.

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Refinement of primary Si in hypereutectic Al–Si alloy by electromagnetic stirring

Cited by 128 publications

References 11 publications

Comparison of Microstructure and Mechanical Properties of A356/SiC Metal Matrix Composites Produced by Two Different Melting Routes

Comparison of Microstructure and Mechanical Properties of A356/SiC Metal Matrix Composites Produced by Two Different Melting Routes

Effect of phosphorus and heat treatment on microstructure of Al-25%Si alloy

Refinement of primary Si in hypereutectic Al-Si alloys by intensive melt shearing

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