Effect of holding temperature on microstructure of an AS91 alloy during semisolid isothermal heat treatment

Ma, Guojun; Li, X.L.; Xiao, Lü; Li, Q.F.

doi:10.1016/j.jallcom.2010.02.115

Cited by 33 publications

(24 citation statements)

References 29 publications

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“…[30] The prevalence of each depends mainly on the particles size distribution and the LVF. [30] The prevalence of each depends mainly on the particles size distribution and the LVF.…”

Section: Effects Of Temperature and Holding Timementioning

confidence: 99%

The Microstructure Evolution of a High Zr‐Containing WE Magnesium Alloy Through Isothermal Semi‐Solid Treatment

et al. 2015

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In the present study, a Mg-Y-RE-Zr alloy was isothermally heat treated in semi-solid mushy region. The experimental alloy was deliberately composed of a higher amount of Zr (1.9 wt%) to take advantages of grain refinement capabilities of zirconium in both dissolved and undissolved condition. Accordingly, the experimental material possessed a fine equiaxed non-dendritic as-cast structure. The effects of holding time and temperature in the semi-solid region were evaluated on the microstructural evolution through applying a predetermined isothermal heat treatment scheme. The results indicate that increasing the isothermal temperature and holding time would increase the liquid fraction, shape factor, and particle size. It is discussed that the particle spheroidization as well as Ostwald ripening mechanism are triggered at higher temperature. The incremental trends of particle size and shape factor are mitigated after mid-term holding time at 600 and 610°C. This observation is attributed to isolating more discrete particles. A lower coarsening rate of solid particles in the present work is related to the dragging effects of redistributed Zr particles in hindering the boundary motion. Furthermore, the results suggest that the microstructure with optimum characteristics would be achieved by holding the material for 30 min at 620°C. 14395, Iran

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“…[30] The prevalence of each depends mainly on the particles size distribution and the LVF. [30] The prevalence of each depends mainly on the particles size distribution and the LVF.…”

Section: Effects Of Temperature and Holding Timementioning

confidence: 99%

The Microstructure Evolution of a High Zr‐Containing WE Magnesium Alloy Through Isothermal Semi‐Solid Treatment

et al. 2015

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“…Ma and co-workers [12,13] reported that the semisolid isothermal heat treatment can modify the Chinese script shaped Mg 2 Si phases in the AS91 alloy. They further established that after heat treatment at 560-575 • C for 20 min, the morphology of Mg 2 Si phases in the alloy changed from the initial Chinese script shape to granule and/or polygon shapes [12]. In another work [14], tensile strength of a cast Si-containing AZ91 alloy was significantly improved by ultrasonic treatment of the melt.…”

Section: Introductionmentioning

confidence: 99%

Effects of Sb addition on the modification of Mg2Si particles and high-temperature mechanical properties of cast Mg–4Zn–2Si alloy

Alizadeh

Mahmudi

2011

Journal of Alloys and Compounds

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“…As is known, the Mg and Si atoms will dissolve into the aluminum matrix and diffuse from the position with large curvature and convexity to the flat interface with lower atoms concentration during T6 heat treatment process, according to the Gibbs‐Thomson Formula (3):

C_{α} true(r true) = C_{a} true(\infty true) \exp true(\frac{2 γ ν_{m}}{R T r} true)

where

C_{a} true(normalr true)

is the concentration of Si or Mg at the position with a curvature radius, r ,

C_{α} true(\infty true)

is the concentration of Si or Mg at flat interface,

γ

is the interfacial energy,

V_{m}

is the precipitate molar volume, T is the temperature, R is the molar gas constant. Therefore, the Si and Mg atoms will diffuse from the sharp tips into the flat interface, which results in the blunt edges of primary Mg 2 Si.…”

Section: Discussionmentioning

confidence: 99%

High Performance of T6‐Treated Al–15Mg₂Si–3Cu Composite Reinforced with Spherical Primary Mg₂Si after the Co‐Modification of Bi + Sr

Chong

Zhao

et al. 2019

Adv Eng Mater

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In this work, the effect of the addition of Bi combined with T6 treatment on microstructure and tensile properties of Sr-modified Al-15Mg 2 Si-3Cu composite is investigated. The results show that the refinement effect of Sr on primary Mg 2 Si is further enhanced via the combined addition of Bi. Interestingly, the truncated octahedral primary Mg 2 Si with the smallest size (11.5 μm) is obtained by adding 0.1% Sr and 1% Bi, which is distinctly different from the cubic shape modified by single 0.1% Sr. Consequently, as a precursor with strong diffusion of Mg and Si atoms during T6 treatment, the truncated octahedral primary Mg 2 Si is completely transformed into spherical morphology with the highest sphericity (0.92) solution treated at 500 C for 6 h. Additionally, further results reveal that the co-modification of Sr þ Bi is more efficient not only in promoting the spheroidization of primary Mg 2 Si, but also obtaining the fine dot-like eutectic Mg 2 Si than single modification of Sr or Bi. As a result, the tensile strength and elongation are significantly enhanced to 374 MPa and 4.75%, respectively. Thereby, this work offers an alternative co-modification system combined with T6 treatment to synthesize the spherical primary Mg 2 Si, which is helpful to prepare the high performance Al-Mg 2 Si composite.

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Effect of holding temperature on microstructure of an AS91 alloy during semisolid isothermal heat treatment

Cited by 33 publications

References 29 publications

The Microstructure Evolution of a High Zr‐Containing WE Magnesium Alloy Through Isothermal Semi‐Solid Treatment

The Microstructure Evolution of a High Zr‐Containing WE Magnesium Alloy Through Isothermal Semi‐Solid Treatment

Effects of Sb addition on the modification of Mg2Si particles and high-temperature mechanical properties of cast Mg–4Zn–2Si alloy

High Performance of T6‐Treated Al–15Mg₂Si–3Cu Composite Reinforced with Spherical Primary Mg₂Si after the Co‐Modification of Bi + Sr

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Effect of holding temperature on microstructure of an AS91 alloy during semisolid isothermal heat treatment

Cited by 33 publications

References 29 publications

The Microstructure Evolution of a High Zr‐Containing WE Magnesium Alloy Through Isothermal Semi‐Solid Treatment

The Microstructure Evolution of a High Zr‐Containing WE Magnesium Alloy Through Isothermal Semi‐Solid Treatment

Effects of Sb addition on the modification of Mg2Si particles and high-temperature mechanical properties of cast Mg–4Zn–2Si alloy

High Performance of T6‐Treated Al–15Mg2Si–3Cu Composite Reinforced with Spherical Primary Mg2Si after the Co‐Modification of Bi + Sr

Contact Info

Product

Resources

About

High Performance of T6‐Treated Al–15Mg₂Si–3Cu Composite Reinforced with Spherical Primary Mg₂Si after the Co‐Modification of Bi + Sr