Synthesis of in-situ reinforced Al composites from AlSiMgO precursors

Hanabe, M.; Aswath, Pranesh B.

doi:10.1016/s1359-6454(97)00085-2

Cited by 29 publications

(16 citation statements)

References 22 publications

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“…FOR the past many years, the different interfacial reaction phases forming in metal matrix composites (MMCs) such as Al 2 O 3 , MgAl 2 O 4 , and MgO in Al/Al 2 O 3 , [1][2][3][4][5][6][7][8][9][10][11][12] Al/oxidized SiC, [13][14][15][16][17] and Al/SiO 2 [21][22][23][24][25] are widely studied. These interfacial products or fine hard ceramic particles improve the wetting and prevent the degradation of reinforcement by direct reactions.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics and Kinetics of the Formation of Al2O3/ MgAl2O4/MgO in Al-Silica Metal Matrix Composite

Sreekumar

Ravi

Pillai

et al. 2008

Metall Mater Trans A

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The formation of Al 2 O 3 , MgAl 2 O 4 , and MgO has been widely studied in different Al base metal matrix composites, but the studies on thermodynamic aspects of the Al 2 O 3 / MgAl 2 O 4 /MgO phase equilibria have been limited to few systems such as Al/Al 2 O 3 and Al/SiC. The present study analyzes the Al 2 O 3 /MgAl 2 O 4 and MgAl 2 O 4 /MgO equilibria with respect to the temperature and the Mg content in Al/SiO 2 system using an extended Miedema model. There is a linear and parabolic variation in Mg with respect to the temperature for MgAl 2 O 4 /MgO and Al 2 O 3 /MgAl 2 O 4 equilibria, respectively, and the influence of Si and Cu in the two equilibria is not appreciable. The experimental verification has been limited to MgAl 2 O 4 /MgO equilibria due to the high Mg content ( ‡0.5 wt pct) required for composite processing. The study has been carried out on two varieties of Al/SiO 2 composites, i.e., Al/Silica gel and Al/Micro silica processed by liquid metallurgy route (stir casting route). MgO is found to be more stable compared to MgAl 2 O 4 at Mg levels ‡5 and 1 wt pct in Al/Silica gel and Al/Micro silica composites, respectively, at 1073 K. MgO is also found to be more stable at lower Mg content (3 wt pct) in Al/Silica gel composite with decreasing particle size of silica gel from 180 micron to submicron and nanolevels. The MgO to MgAl 2 O 4 transformation has taken place through a series of transition phases influenced by the different thermodynamic and kinetic parameters such as holding temperature, Mg concentration in the alloy, holding time, and silica particle size.

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Section: Introductionmentioning

confidence: 99%

Thermodynamics and Kinetics of the Formation of Al2O3/ MgAl2O4/MgO in Al-Silica Metal Matrix Composite

Sreekumar

Ravi

Pillai

et al. 2008

Metall Mater Trans A

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“…It has been reported in preparing aluminum matrix composites that the reactions among aluminum, magnesium and SiO 2 results in the formation of MgAl 2 O 4 and MgO. [10][11][12] These results suggest that Al-Mg oxide and Mg oxide observed in Figs. 6 and 7 are MgAl 2 O 4 and MgO, respectively.…”

Section: Methodsmentioning

confidence: 62%

Removal of Magnesium from Aluminum Scrap by Compound-Separation Method Using Shirasu as an Additive

Hashiguchi

Sueyoshi

2010

Mater. Trans.

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The removal of magnesium from the molten aluminum scrap containing magnesium was examined by compound-separation method. As an additive, three types of Shirasu (a natural resource in South Kyushu, Japan) with different particle sizes were used. The addition of Shirasu to the molten aluminum scrap at 1023 K resulted in the formation of MgAl 2 O 4 and MgO by the reactions among SiO 2 and Al 2 O 3 in Shirasu and magnesium in the molten scrap. It was feasible to remove magnesium by separating these reaction products as dross. Assuming that all the Shirasu reacted with magnesium in the molten scrap, the amount of removed magnesium, which was calculated from these reactions, was in agreement with the measured one. In the addition of flaky Shirasu with a small particle size, the amount of removed magnesium increased linearly with agitation time after Shirasu addition. This is because the over-all reaction is mainly controlled by a surface-controlled reaction. In the addition of granular Shirasu with a large particle size, the increase in magnesium removal was parabolic. This is because the over-all reaction is mainly by a diffusion-controlled reaction.

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“…[16] In the case of thermodynamically unstable oxides (e.g., volatile oxides such as SiO 2 ) added externally in liquid aluminum, formation of stable oxide crystals can be maximized by complete conversion of the volatile oxides. [17] The same reactions were demonstrated upon conversion of volatile oxides into interconnected fibers of MgAl 2 O 4 (spinel) phase in an Al alloy by self-propagating, high-temperature synthesis of powder compacts. [18,19] It was reported that oxide particles work better as nucleating substrates when the melt is subjected to an external physical field.…”

Section: Introductionmentioning

confidence: 70%

Potential of an Al-Ti-MgAl2O4 Master Alloy and Ultrasonic Cavitation in the Grain Refinement of a Cast Aluminum Alloy

Sreekumar

Babu

Eskin

2016

Metall Mater Trans B

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A new grain refining master alloy containing MgAl 2 O 4 and Ti was synthesized by in situ reaction of TiO 2 particles in an Al-Mg melt. MgAl 2 O 4 particles formed were distributed in the melt by ultrasonic cavitation processing. The obtained master alloy showed considerable (50 pct) grain refining ability in a commercial A357-type Al-Si alloy. Ultrasonication contributed further to 25 pct in the grain refinement. In comparison with a commercial Al-5 pct Ti-1 pct B master alloy, the efficiency of the new master alloy is less at a lower addition rate. Nevertheless, both master alloys performed similarly at higher additions. The strength and ductility of the inoculated and ultrasonicated alloy showed at least a 10 pct and a 50 pct increase, respectively, as compared with non-grain-refined alloy and a similar mechanical performance in comparison with the alloy inoculated with Al-5 pct Ti-1 pct B master alloy.

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Synthesis of in-situ reinforced Al composites from AlSiMgO precursors

Cited by 29 publications

References 22 publications

Thermodynamics and Kinetics of the Formation of Al2O3/ MgAl2O4/MgO in Al-Silica Metal Matrix Composite

Thermodynamics and Kinetics of the Formation of Al2O3/ MgAl2O4/MgO in Al-Silica Metal Matrix Composite

Removal of Magnesium from Aluminum Scrap by Compound-Separation Method Using Shirasu as an Additive

Potential of an Al-Ti-MgAl2O4 Master Alloy and Ultrasonic Cavitation in the Grain Refinement of a Cast Aluminum Alloy

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