The influence of Mg<SUB align=right>17Al<SUB align=right>12 phase volume fraction on the corrosion behaviour of AZ91 magnesium alloy

The effects of samarium (Sm) on the microstructure and corrosion behavior of AZ91 magnesium alloy treated by ultrasonic vibration were investigated by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and electrochemical measurements. The results showed that the addition of Sm resulted in the formation of Al2Sm, which reduced the volume fraction of the β-Mg17Al12 phase and changed its morphology to fine granular. The AZ91–Sm alloys treated by ultrasonic vibration revealed relatively lower weight loss, hydrogen evolution, and corrosion current density values compared to the ultrasonic-treated AZ91 alloy prepared without Sm. Locally, a coarse β phase in the ultrasonic-treated AZ91 alloy accelerated the possibility of micro-galvanic corrosion growing into the matrix. In the prepared AZ91–Sm alloys treated by ultrasonic vibration, the fine β and Al2Sm phases reduced the probability of micro-galvanic corrosion growth and, therefore, formed a uniform corrosion layer on the surface of the alloys.

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Local and global electrochemical impedances applied to the corrosion behaviour of an AZ91 magnesium alloy

Corrosion Science ◽

10.1016/j.corsci.2009.05.005 ◽

2009 ◽

Vol 51 (8) ◽

pp. 1789-1794 ◽

Cited By ~ 110

Author(s):

Gonzalo Galicia ◽

Nadine Pébère ◽

Bernard Tribollet ◽

Vincent Vivier

Keyword(s):

Magnesium Alloy ◽

Corrosion Behaviour ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium

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The use of a multiscale approach in electrochemistry to study the corrosion behaviour of as-cast AZ91 magnesium alloy

Journal of Solid State Electrochemistry ◽

10.1007/s10008-015-2877-9 ◽

2015 ◽

Vol 19 (8) ◽

pp. 2379-2390 ◽

Cited By ~ 10

Author(s):

Iwona Kot ◽

Halina Krawiec

Keyword(s):

Magnesium Alloy ◽

Corrosion Behaviour ◽

Multiscale Approach ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium

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Nanocrystalline Microstructure in AZ91 Magnesium Alloy Prepared with Cryogenic Treatment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.575-576.386 ◽

2013 ◽

Vol 575-576 ◽

pp. 386-389

Author(s):

Gui Rong Li ◽

Hong Ming Wang ◽

Yun Cai ◽

Yu Tao Zhao ◽

Jun Jie Wang ◽

...

Keyword(s):

Magnesium Alloy ◽

Cryogenic Temperature ◽

Power Transmission ◽

Volume Fraction ◽

Cryogenic Treatment ◽

Solution Treatment ◽

Aging Treatment ◽

High Volume ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium

In order to make clear about the effect of cryogenic temperature on the microstructure evolution of alloy, the as-cast AZ91 magnesium alloy was subjected to the cryogenic treatment after solution treatment (415°C,5h) and aging treatment (190°C, 16h) with the protection of graphite power. Transmission Electron Microscope was utilized to characterize the microstructure of as-treated sample. The results show that a high volume fraction of nanocrystalline can be found in the treated alloys with the average sizes are about 55nm. The phenomenon highlights the importance of cryogenic temperature in forming nanostructures. During the continuous contraction of alloy the micro dynamic plastic deformation induces the generation, movement and accumulation of high-density dislocations that give rise to the formation of nanocrystalline during recovery and recrystallization.

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Effect of Modification on Microstructure and Properties of AZ91 Magnesium Alloy

Crystals ◽

10.3390/cryst10060536 ◽

2020 ◽

Vol 10 (6) ◽

pp. 536

Author(s):

Andrzej Kiełbus ◽

Robert Jarosz ◽

Adam Gryc

Keyword(s):

Mechanical Properties ◽

Solid Solution ◽

Magnesium Alloy ◽

Volume Fraction ◽

Az91 Alloy ◽

Carbon Powder ◽

Az91 Magnesium Alloy ◽

Microstructure And Properties ◽

Az91 Magnesium ◽

Cast Magnesium

Refinement of α-Mg solid solution grains has a significant influence on the improvement of mechanical properties of cast magnesium alloys. In the article, the effects of three modifiers on microstructure and properties of AZ91 magnesium alloy casted to a sand mould were described. Overheating, hexachloroethane and wax-CaF2-carbon powder were applied. The research procedure comprised microstructure analysis by means of light microscopy, scanning electron microscopy and quantitative analysis with AnalySIS Pro® software and mechanical properties’ investigation. The microstructure of AZ91 alloy in the as-cast condition consists of α-Mg solid solution with precipitates of Mg17Al12, Mg2Si and Al8Mn5 phases. It was reported that all applied modifiers cause refinement of α-Mg solid solution grains and a decrease of the volume fraction of α-Mg+Mg17Al12 compound discontinuous precipitates. The best results were obtained in the case of wax-CaF2-carbon powder.

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