Tensile properties of the semi-solid state in solidifying aluminum alloys

The aim of this research was to study semi-solid state joining of SSM A356 aluminum alloys which welded at its semi-solid state temperature by using oxygen – acetylene heat source. Then a stirrer was used to stir the weld seam. The joining parameters were rotation speed 1,110 with welding speed 120 mm/min and rotation speed 1,320 rpm with welding speed 160 mm/min. The joining temperatures were 575-590 and 590-610 oC. Joining was performed under nitrogen shielding gas and under argon shielding gas. Physical appearance, macrostructure, microstructure and mechanical properties were analyzed. The results indicated that the weld’s microstructure consisted of globular structure. In addition, porosities were found at the top of weld. However, minimum porosities were obtained from joints under argon shielding gas. The highest tensile strength was achieved from rotation speed at 1,110 rpm with welding speed at 120 mm/min under argon shielding gas with the value of 173 MPa. The joint efficiency was 86 % compared to the base metal.

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A New Approach to Determine Tensile Stress-Strain Evolution in Semi-Solid State at Near-Solidus Temperature of Aluminum Alloys

Metals ◽

10.3390/met11030396 ◽

2021 ◽

Vol 11 (3) ◽

pp. 396

Author(s):

Jovid Rakhmonov ◽

Mohamed Qassem ◽

Daniel Larouche ◽

Kun Liu ◽

Mousa Javidani ◽

...

Keyword(s):

Solid State ◽

Aluminum Alloys ◽

Accurate Determination ◽

Solidus Temperature ◽

Hot Tearing ◽

Image Correlation ◽

Correlation Technique ◽

Stress Strain ◽

Strain Evolution ◽

Semi Solid

Accurate determination of the materials’ strength and ductility in the semi-solid state at near-solidus temperatures is essential, but it remains a challenging task. This study aimed to develop a new method to determine the stress-strain evolution in the semi-solid state of aluminum alloys within the Gleeble 3800 unit. Stress evolution was determined by the newly developed “L-gauge” method, which converted the displacement of the “restrained” jaw, measured using an L-gauge, into the force. This method gives the possibility to determine the flow stress more accurately, especially for the very low stress rang (1–10 MPa) in the semi-solid state at near-solidus temperatures. The digital image correlation technique implemented in the Gleeble unit allowed effective measurement of the heterogeneous strain fields evolving within the specimen under tensile loading. Therefore, the stress-strain curves measured in the semi-solid state help to better understand the alloy’s susceptibility to hot tearing. The results of an AA6111 alloy under different liquid fractions (2.8% at 535 °C and 5.8% at 571 °C) were demonstrated. The reliable stress-strain data and heterogenous strain distribution are beneficial to develop the thermomechanical models and hot-tearing criteria.

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Influence of Si and Mg Contents on the Mechanical Behavior of Al-Mg-Si Alloys in the Semi-Solid State under Isothermal and Non-Isothermal Conditions

Materials Science Forum ◽

10.4028/www.scientific.net/msf.690.73 ◽

2011 ◽

Vol 690 ◽

pp. 73-76

Author(s):

Eliane Giraud ◽

Michel Suéry ◽

Michel Coret

Keyword(s):

Solid State ◽

Aluminum Alloys ◽

Mechanical Behavior ◽

Solid Fraction ◽

Solid Alloy ◽

Isothermal Conditions ◽

Formation Of Cracks ◽

Semi Solid ◽

Si Content ◽

Mg Content

The shear behavior of aluminum alloys containing increased amounts of Si or Mg compared with the 6061 alloy has been investigated by carrying out isothermal and non-isothermal tests in the mushy state during solidification. In isothermal conditions, it is shown that (i) an increase in Mg content leads to a more resistant semi-solid alloy compared with the 6061 alloy for the same solid fraction and (ii) an increase in Si content leads to a more brittle mushy alloy. In non-isothermal conditions, stress increases continuously with decreasing temperature with the formation of cracks for some compositions. This study shows that an increase in Mg content seems to be the most appropriate solution to reduce the formation of cracks in a solidifying 6061 alloy.

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Rheological Investigation of Semisolid AlSi7 Alloy by Means of Oscillation Experiments

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.285.385 ◽

2019 ◽

Vol 285 ◽

pp. 385-390

Author(s):

Marialaura Tocci ◽

Annalisa Pola ◽

Michael Modigell

Keyword(s):

Solid State ◽

Aluminum Alloys ◽

Mechanical Analysis ◽

Constant Condition ◽

Material Models ◽

Die Filling ◽

Semisolid Alloys ◽

Semi Solid ◽

Frequency Sweeps ◽

Filling Simulation

Dynamic Mechanical Analysis (DMA) of semisolid aluminum alloys was performed in a rheometer of Searle type. DMA was applied on a binary AlSi7 alloy to demonstrate the advantages of the method for the investigation of the behavior of alloys in semi-solid state and it was compared to classical shear experiments. Frequency sweeps, amplitude sweeps as well as constant condition experiments (CCE) were performed. It became obvious that elastic properties are getting more dominant with increasing resting time without shearing. The shift from a more viscous to more elastic nature of the material can be quantified. Interestingly, it was found that the semi-empirically based Cox-Merz rule, usually applied for polymers, holds for the semisolid material as well. This allows investigating the shear viscosity under different relevant conditions - important to improve material models for die-filling simulation of semisolid alloys.

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The Tensile Properties of Semi-Solid Aluminum Alloys

International Journal of Forming Processes ◽

10.3166/ijfp.7.233-260 ◽

2004 ◽

Vol 7 (1-2) ◽

pp. 233-260 ◽

Cited By ~ 5

Author(s):

Marius R Twite ◽

John A Spittle ◽

Stephen GR Brown

Keyword(s):

Aluminum Alloys ◽

Tensile Properties ◽

Solid Aluminum ◽

Semi Solid

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Tensile properties of as-deformed 2A50 aluminum alloy in semi-solid state

Transactions of Nonferrous Metals Society of China ◽

10.1016/s1003-6326(09)60345-9 ◽

2010 ◽

Vol 20 (9) ◽

pp. 1597-1602 ◽

Cited By ~ 7

Author(s):

Zhi-ming DU ◽

Gang CHEN ◽

Jun LIU ◽

Shui-sheng XIE

Keyword(s):

Aluminum Alloy ◽

Solid State ◽

Tensile Properties ◽

Semi Solid

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ALCOA QC-10

Alloy Digest ◽

10.31399/asm.ad.al0423 ◽

2009 ◽

Vol 58 (7) ◽

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Aluminum Alloys ◽

Physical Properties ◽

Tensile Properties ◽

Mold Material ◽

Cast Products

Abstract Aluminum has long been accepted as a mold material. This alloy has a combination of faster machining, highest heat transfer, lighter weight, higher strength in thick sections, and greater thermal conductivity than other aluminum alloys. This datasheet provides information on physical properties, hardness, elasticity, and tensile properties. It also includes information on forming and machining. Filing Code: AL-423. Producer or source: Alcoa Forged and Cast Products.

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