An Effective and Economical Method to Improve Structural Homogeneity and Mechanical Properties of Al–Mg Alloy Processed by ECAE

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to study the microstructure and mechanical behavior of an Al-Cu-Mg alloy after tensile test at 125°C, 150°C, 175°C and 200 °C, respectively. The yield strength and ultimate tensile strength decreased with the increase of temperature, while the elongation increased firstly and then decreased. The S and S′ precipitate after tension at elevated temperatures. When the temperature was higher than 175°C, the precipitate coarsens rapidly. The alloys displayed a shear fracture features at elevated temperature. The larger S′ and S phase coarsened and dropped which forming crack in the grain boundaries and precipitate interfaces, resulting in the decrease of the elongation of the alloy.

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Effect of Rolling Conditions on Microstructure and Mechanical Properties of AZ31 Mg Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.529 ◽

2005 ◽

Vol 475-479 ◽

pp. 529-532

Author(s):

Tae Kwon Ha ◽

Hwan Jin Sung ◽

Woo Jin Park ◽

Sang Ho Ahn

Keyword(s):

Mechanical Properties ◽

Uniform Elongation ◽

Warm Rolling ◽

Thickness Reduction ◽

Mg Alloy ◽

Roll Speed ◽

Single Pass ◽

Microstructure And Mechanical Properties ◽

Roll Temperature ◽

Az31 Mg Alloy

The effect of warm rolling under various conditions on the microstructure and mechanical property was investigated using an AZ31 Mg alloy sheet. Several processing parameters such as initial thickness, thickness reduction by a single pass rolling, rolling temperature, roll speed, and roll temperature were varied to elicit an optimum condition for the warm rolling process of AZ31 Mg alloy. Microstructure and mechanical properties were measured for specimens subjected to rolling experiments of various conditions. Warm rolling of 30% thickness reduction per pass was possible without any side-crack at temperatures as low as 200oC under the roll speed of 30 m/min. The initial microstructure before rolling was the mixed one consisting of partially recrystallized and cast structures. Grain refinement was found to occur actively during the warm rolling, producing a very fine grain size of 7 µm after 50% reduction in single pass rolling at 200oC. Yield strength of 204MPa, tensile strength of 330MPa and uniform elongation of 32% have been obtained in warm rolled sheets.

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Investigations on Microstructure Evolution and Deformation Behavior of Aged and Ultrafine Grained Al-Zn-Mg Alloy Subjected to Severe Plastic Deformation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.667-669.253 ◽

2010 ◽

Vol 667-669 ◽

pp. 253-258

Author(s):

Wei Ping Hu ◽

Si Yuan Zhang ◽

Xiao Yu He ◽

Zhen Yang Liu ◽

Rolf Berghammer ◽

...

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Plastic Deformation ◽

Grain Size ◽

Severe Plastic Deformation ◽

Microstructure Evolution ◽

Deformation Behavior ◽

Deformation Mechanisms ◽

Mg Alloy ◽

Ultrafine Grained

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.

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