Effect of predeformation on the globular grains in AZ91D alloy during strain induced melt activation (SIMA) process

Lin, Huaqiang; Wang, J.G.; Wang, H.Y.; Jiang, Qi–Chuan

doi:10.1016/j.jallcom.2006.05.067

Cited by 54 publications

(44 citation statements)

References 16 publications

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“…9, the average grain sizes of both the central and peripheral parts are reduced with the increase of ARR. The variation tendency experiences three different stages: precipitous reduction, gentle reduction and unobvious change, which is similar to the investigation reported by Lin et al, 27) and Amir et al 24) Moreover, although the average grain size of the central part is always smaller than that of the peripheral part, their differences (marked with H1, H2, H3 and H4) are decreased obviously as ARR increases from 30% to 85%.…”

Section: Effects Of Arr On Microstructure Of 6063 Al Alloy Barsupporting

confidence: 87%

Grain Refinement of Aluminum Alloy Bar by a Modified RAP Process for Semi-Solid Forming

2017

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A modi ed Recrystallization and Partial Melting (RAP) process including Radial Forging (RF) and Semi-Solid Isothermal Treatment (SSIT) was proposed to re ne the grains of 6063 Al alloy bar for semi-solid forming. The 6063 Al alloy bar (φ120 mm × 800 mm) was deformed by RF into a stepped shaft with different Area Reduction Ratios (ARRs) at the temperature of 300 C, and then the samples cut from both the central and peripheral parts of the RF-deformed bar were treated with SSIT at 630 C for 10 min. The effect of ARR on the microstructural evolution of semi-solid 6063 Al alloy was investigated. Results showed that, during the RF process, the microstructures of the samples became denser as the ARR increased. After SSIT, with the increase of ARR, the average grain sizes of both the central and peripheral parts were reduced and the spheroidization degrees of both the central and peripheral parts were improved. The variation tendency of grain size experienced three different stages: precipitous reduction, gentle reduction and unobvious change. Besides, the differences between grain sizes of the peripheral and central parts were gradually decreased with the increase of ARR. Additionally, the optimal process parameter for re ning grains was 70% ARR at 630 C for 10 min.

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Section: Effects Of Arr On Microstructure Of 6063 Al Alloy Barsupporting

confidence: 87%

Grain Refinement of Aluminum Alloy Bar by a Modified RAP Process for Semi-Solid Forming

2017

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“…Various routes have been developed for production of thixotropic aluminum, magnesium, lead, and also ferrous alloys including mechanical and magneto-hydrodynamic (MHD) stirring processes, the thermo-mechanical strain induced melt activation (SIMA) process and the spray casting process [7][8][9]. The SIMA process which is based on the mechanical work was introduced by Young et al [10] in the 1980s.…”

Section: Introductionmentioning

confidence: 99%

“…The SIMA process which is based on the mechanical work was introduced by Young et al [10] in the 1980s. This process has received great attention in recent years due to its simplicity, low equipment costs, and its capability to process many engineering alloys [8]. The two main stages of the SIMA process are cold or warm plastic deformation and then partial remelting in the semi-solid range [11,12].…”

Section: Introductionmentioning

confidence: 99%

Phase Evolution and Mechanical Behavior of the Semi-Solid SIMA Processed 7075 Aluminum Alloy

Binesh

Aghaie-Khafri

2016

Metals

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Microstructural and mechanical behaviors of semi-solid 7075 aluminum alloy were investigated during semi-solid processing. The strain induced melt activation (SIMA) process consisted of applying uniaxial compression strain at ambient temperature and subsequent semi-solid treatment at 600-620˝C for 5-35 min. Microstructures were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). During the isothermal heating, intermetallic precipitates were gradually dissolved through the phase transformations of α-Al + η (MgZn 2 ) Ñ liquid phase (L) and then α-Al + Al 2 CuMg (S) + Mg 2 Si Ñ liquid phase (L). However, Fe-rich precipitates appeared mainly as square particles at the grain boundaries at low heating temperatures. Cu and Si were enriched at the grain boundaries during the isothermal treatment while a significant depletion of Mg was also observed at the grain boundaries. The mechanical behavior of different SIMA processed samples in the semi-solid state were investigated by means of hot compression tests. The results indicated that the SIMA processed sample with near equiaxed microstructure exhibits the highest flow resistance during thixoforming which significantly decreases in the case of samples with globular microstructures. This was justified based on the governing deformation mechanisms for different thixoformed microstructures.

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“…The semi-solid forming (SSF) process is an advanced net-shape forming technology in which components are formed in the semi-solid state of the alloy. Because the process is characterized by low forming temperature, less energy consumption, reduced solidification shrinkage and long mold life, it has attracted considerable attention [3]. The preparation of semi-solid slurry is critical in SSF.…”

Section: Introductionmentioning

confidence: 99%

“…This method is particularly suitable for the preparation of semi-solid magnesium alloy. The current research on the preparation of semi-solid slurry by SIMA process has mainly concentrated on the evolution of non-dendrite microstructure [3,[10][11][12][13]. However, little has been reported on the selection of deformation degrees of billets and quantitative analysis of distortion energy stored in alloy with different deformation degrees.…”

Section: Introductionmentioning

confidence: 99%

The Deformation Microstructure and Eutectic Melting Activation Energy of AZ91D Alloy~!2008-08-15~!2008-12-12~!2009-01-21~!

Wang¹,

Dong²,

Zhi-kang³

et al. 2010

TOMSJ

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Abstract:The effect of deformation degree on deformation microstructure in the preparation of semi-solid AZ91D alloy billet by Strain Induced Melt Activated (SIMA) process was studied and the relationship between deformation degree and eutectic melting activation energy was studied by Differential Scanning Calorimetry (DSC). The results showed that with an increase in deformation degree, the original microstructure of the alloy changed from dendrites to fragmentary grains where there were twins and dislocations. When the deformation degree was 40%, the decreased amount of eutectic melting activation energy was not significant. Melting point of eutectic decreased slightly with increasing deformation degree.

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Effect of predeformation on the globular grains in AZ91D alloy during strain induced melt activation (SIMA) process

Cited by 54 publications

References 16 publications

Grain Refinement of Aluminum Alloy Bar by a Modified RAP Process for Semi-Solid Forming

Grain Refinement of Aluminum Alloy Bar by a Modified RAP Process for Semi-Solid Forming

Phase Evolution and Mechanical Behavior of the Semi-Solid SIMA Processed 7075 Aluminum Alloy

The Deformation Microstructure and Eutectic Melting Activation Energy of AZ91D Alloy~!2008-08-15~!2008-12-12~!2009-01-21~!

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