Effect of growth restricting factor on grain refinement of aluminum alloys

Chandrashekar, T. K.; Muralidhara, M. K.; Kashyap, K. T.; Rao, P. Rama

doi:10.1007/s00170-007-1336-x

Cited by 59 publications

(27 citation statements)

References 6 publications

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“…These results are consistent with previous studies (Girisha et al, 2012) that Mg can reduce the size of grains of aluminum. This result is also consistent with the theory of the Restriction Growth Factor (GRF) in which the segregation power of the Mg element in the aluminum alloy can be predicted by knowing the value of the growth-restriction parameter Q of Mg in the aluminum (Chandrashekar et al, 2009) by using Equation 1 as follows:…”

Section: Microstructure Of Alzrce/mg/al 2 O 3 Nanocompositessupporting

confidence: 88%

Effects of Magnesium on Properties of AlZrCe-Mg-Al2O3 Nanocomposites

Kirman

Zulfia²,

Suharno³

2016

IJTech

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Aluminum alloy is one of the materials found in many applications, especially for electrical conductor materials. AlZrCe alloy reinforced by Al 2 O 3 nanoparticles with Mg addition is proposed as one of the alternative materials to replace Aluminum Conductor Steel Reinforced (ACSR) as an aluminum conductor. Aluminum alloy Al-0.12%Zr-0.15%Ce as a master alloy was added with various weights of magnesium (Mg) from 2 to 5 wt% and was reinforced with 1.2% volume fraction of Al 2 O 3 nanoparticles with particle sizes less than 80 nm. The molten metal matrix was blended with the reinforcement by a stirrer with a rotational speed of 500 rpm at a temperature of 750 o C in an argon gas environment and casted by gravity casting. The objective of this research was to investigate the effect of magnesium on microstructural changes, electrical conductivity, and mechanical properties, such as tensile strength and hardness of the composites. The microstructure observation results showed that the greater the Mg content in composites up to 5%, the smaller the grain size of the composite matrix, wherein the grain size of the composite without Mg is 28 μm, while the grain size of the composite with Mg of 2%, 3% and 5% are 27 μm, 17 μm and 9 μm respectively. Similarly, tensile strength and hardness increased with increasing levels of Mg to 5% where the addition of 5% Mg, the tensile strength increased from 106 to 204 MPa and hardness increased from 30 to 68 BHN. In contrast, the electrical conductivity sharply decreased, due to the addition of Mg in the composite with a gradient of reduction, to 2.74% IACS (International Annealed Copper Standard) for every increasing 1% Mg. In which the electrical conductivity of the composite without Mg is 55.1% IACS and after adding 5 wt% Mg, it decreased to 41.3% IACS.

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Section: Microstructure Of Alzrce/mg/al 2 O 3 Nanocompositessupporting

confidence: 88%

Effects of Magnesium on Properties of AlZrCe-Mg-Al2O3 Nanocomposites

Kirman

Zulfia²,

Suharno³

2016

IJTech

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“…In general, the refinement of microstructure mainly has the following methods, such as chemical elements modification [9][10][11], electromagnetic vibration [12], ultrasonic vibration [13], and mechanical vibration [14]. The mechanical vibration has the potential to be a simple, economic, and effective method to refine microstructure and improve mechanical properties [15,16], which was first applied on the steel by Chernov [17].…”

Section: Introductionmentioning

confidence: 99%

Effects of vibration frequency on microstructure, mechanical properties, and fracture behavior of A356 aluminum alloy obtained by expendable pattern shell casting

Jiang

Wang

et al. 2015

Int J Adv Manuf Technol

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A simple, economic, and effective mechanical vibration method was introduced into the solidification process of A356 aluminum alloy during the expendable pattern shell casting process, and the effects of vibration frequency on microstructure, mechanical properties, and fracture behavior of the A356 alloy were investigated. Obtained results showed that the sizes and morphologies of α-Al primary phase and eutectic silicon particles were significantly improved by the mechanical vibration, and the mechanical properties and density of the A356 alloy greatly increased. With increasing vibration frequency, the grain size and secondary dendrite arm spacing (SDAS) continuously decreased, and the shape factor increased, and the mechanical properties and density of the A356 alloy gradually increased. With a vibration frequency of 100 Hz, the grain size and SDAS decreased by 32 and 19 %, respectively, and the shape factor increased by 262 %, and the average length, width, and aspect ratio of the silicon particles decreased by 45, 6, and 42 %, respectively, compared to that of the sample without vibration. Meanwhile, the tensile strength, yield strength, elongation, and hardness of the A356 alloy sample were, respectively, 35, 42, 57, and 28 % higher than those of the sample without vibration. In addition, the mechanical vibration changed the fractograph of the A356 alloy from a clear brittle fracture nature of the alloy without vibration to an obvious dimple fracture nature, and with the increase of vibration frequency, the dimples were very deep and well distributed with a high density.

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“…Heterogeneous nucleation theory has been described in papers [1,17]. According to nucleation theory, the formation of an effective grain nucleus related to the volume free energy that was related to the change for liquid to solid phase and the interface fee energy that was essential for a new interface formation in the solidification [18].…”

Section: Cooling Curve Analysismentioning

confidence: 99%

Improvement of Grain Refinement Efficiency in Pure Aluminum by Embryos Proliferation

Zhang

Sun

Zhou

et al. 2014

Materials and Manufacturing Processes

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The present research was undertaken to investigate the improvement of embryos proliferation process on refining efficiency of Al-5Ti-1B master alloy on the commercial purity aluminum. In order to achieve the proliferation of embryos, a special casting launder was designed and used. The polarized light microstructure showed that the fine equiaxed and better homogeneous grains were obtained through embryos proliferation. With the same addition level of 0.2% Al-5Ti-1B master alloy, the average grain sizes were 149 mm for direct casting and 102 mm for special casting launder, respectively. The analyses showed that the free nucleation energy barrier was smaller and the nucleation rate was greater when casting through embryos proliferation processing than direct casting. The experimental results indicated that the refinement efficiency of commercial purity aluminum could be improved significantly through embryos proliferation processing.

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Effect of growth restricting factor on grain refinement of aluminum alloys

Cited by 59 publications

References 6 publications

Effects of Magnesium on Properties of AlZrCe-Mg-Al2O3 Nanocomposites

Effects of Magnesium on Properties of AlZrCe-Mg-Al2O3 Nanocomposites

Effects of vibration frequency on microstructure, mechanical properties, and fracture behavior of A356 aluminum alloy obtained by expendable pattern shell casting

Improvement of Grain Refinement Efficiency in Pure Aluminum by Embryos Proliferation

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