Effect of Isothermal Holding Time on the Volume Fractions of Primary ^|^beta;-Sn in Sn-Ag Alloys in Solid-Liquid Region

In order to produce a high quality and cost effective part in the rheocasting process for an automobile industry it has been important to develop a slurry-on-demand process, which can manufacture the semi-solid slurry having a fine and globular structure of primary solid phase. The morphology of primary solid phase of semi-solid slurry is coarsened and globularized during an isothermal holding process in a solid-liquid region. Accordingly, in this paper, the microstructural evolution of semi-solid slurry during the isothermal holding at a various temperature in solid-liquid region was investigated to examine a coarsening and globularization behavior of primary solid phase. The semi-solid slurry of Al alloy was produced in a slurry maker using a multiplex-type slurry cup that we developed recently. A size of primary solid phase was the finer at the higher holding temperature, but under a constant holding time a roundness degree of primary solid phase was the lower at the lower holding temperature. Also, a coarsening rate of primary solid phase was not considered to be affected significantly by a holding temperature even though a little lower coarsening rate was obtained at the higher holding temperature.

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Roles of the semisolid heating on the microstructure of a hypereutectic Al–Fe–Cu alloy

Scientific Reports ◽

10.1038/s41598-021-80983-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wei Wang ◽

Bo Liu

Keyword(s):

Volume Fraction ◽

High Volume ◽

Holding Time ◽

Second Phase ◽

Liquid Region ◽

Cu Alloy ◽

Initial Stage ◽

Coarsening Kinetics ◽

Increasing Temperature ◽

Solid Liquid

AbstractA hypereutectic Al–Fe–Cu alloy with a high-volume fraction ferro-aluminum second phase (AlFe phases for short) was reheated in the solid–liquid region and the microstructure evolution was investigated. During semisolid heating, the high-melting AlFe phases in the Al–Fe–Cu alloy were demonstrated to stunt the grain growth and to block the liquid coalescing and the solid moving. Consequently, the grain sizes in the alloy increased rapidly and then slowly with increasing holding time, and the grains increased gradually with increasing temperature. Smaller grain grew into the large grain but it did not continually grow into the larger grain with increasing temperature or holding time. The shape factor (SF) of the alloy increased gradually and then decreased quickly with increasing temperature or holding time. The major alloying elements in addition to magnesium in the hypereutectic Al–Fe–Cu alloy were finally enriched at the grain boundaries or around the AlFe phases. Besides dissolving in the grains or AlFe phases, copper also diffused between the grains or around AlFe phases, resulting in the formation of diverse Cu-enriched zones. Cu constituents in the inter-grains are outnumbered in the intra-grains. The coarsening kinetics of the alloy was controlled by grain boundary diffusion. The coarsening rate constants K in the initial stage of heating (5–20 min) were several times larger than that in the later stage of heating (20–60 min), indicating the blocking effect of AlFe phases on coarsened grain being obvious.

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Effect of Isothermal Holding in Solid-Liquid Phase Region on Mg2Si Morphology in Hypereutectic Al-Si In Situ Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.430-432.711 ◽

2012 ◽

Vol 430-432 ◽

pp. 711-714

Author(s):

Zheng Liu ◽

Hong Biao Xu ◽

Kai Cao ◽

Mei Yan Huang

Keyword(s):

Liquid Phase ◽

Shape Factor ◽

Isothermal Holding ◽

Phase Region ◽

Holding Time ◽

In Situ Composite ◽

Size And Morphology ◽

Solid Liquid ◽

Holding Temperature

Mg2Si reinforced hypereutectic Al-Si in-situ composite was prepared and the effects of the isothermal holding temperature and time on Mg2Si in the composite were researched. The results showed that there were the important effects of holding temperature and time in the solid-liquid phase region of the Al-Si alloy on the size and morphology of Mg2Si. The size and morphology of Mg2Si became smaller and round with the rising of the holding temperature and prolonging of the holding time. The suitable technology in the test was obtained, in which when being held at 615°C for 300s, the size of Mg2Si decreased to 20.54μm and the shape factor of Mg2Si reached about 0.67.

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Properties of ZrO2–Al2O3 composite as a function of isothermal holding time

International Journal of Refractory Metals and Hard Materials ◽

10.1016/j.ijrmhm.2006.12.005 ◽

2007 ◽

Vol 25 (5-6) ◽

pp. 374-379 ◽

Cited By ~ 31

Author(s):

J.K.M.F. Daguano ◽

C. Santos ◽

R.C. Souza ◽

R.M. Balestra ◽

K. Strecker ◽

...

Keyword(s):

Isothermal Holding ◽

Holding Time ◽

Al2o3 Composite

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Temperature-induced structural transition of ceria by bulk reduction under hydrogen atmosphere

CrystEngComm ◽

10.1039/c8ce00961a ◽

2018 ◽

Vol 20 (31) ◽

pp. 4359-4363 ◽

Cited By ~ 4

Author(s):

Takeshi Matsukawa ◽

Akinori Hoshikawa ◽

Toru Ishigaki

Keyword(s):

High Temperature ◽

Structural Transition ◽

Isothermal Holding ◽

Hydrogen Atmosphere ◽

Holding Time

Ceria (CeO2) was kinetically reduced in hydrogen depending on the isothermal holding time at high temperature.

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Comparison of the Volume Fractions of Primary Sn Depending on the Holding Time in Sn-Ag and Sn-Pb Alloys

PRICM ◽

10.1002/9781118792148.ch307 ◽

2013 ◽

pp. 2479-2485

Author(s):

Yasuhiro Nagatomo ◽

Hisao Esaka ◽

Kei Shinozuka

Keyword(s):

Holding Time ◽

Volume Fractions

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Microstructural Evolution of Electromagnetically Stirred Al Alloy during Isothermal Reheating in Solid-Liquid Region

Materials Science Forum - Eco-Materials Processing & Design VI ◽

10.4028/0-87849-966-0.338 ◽

2005 ◽

pp. 338-341

Author(s):

Dock Young Lee ◽

Ki Bae Kim ◽

Do Hyang Kim

Keyword(s):

Microstructural Evolution ◽

Al Alloy ◽

Liquid Region ◽

Solid Liquid

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Comparison of the Volume Fractions of Primary Sn Depending on the Holding Time in Sn-Ag and Sn-Pb Alloys

Proceedings of the 8th Pacific Rim International Congress on Advanced Materials and Processing ◽

10.1007/978-3-319-48764-9_307 ◽

2013 ◽

pp. 2479-2485

Author(s):

Yasuhiro Nagatomo ◽

Hisao Esaka ◽

Kei Shinozuka

Keyword(s):

Holding Time ◽

Volume Fractions

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Effect of isothermal process parameters on semi-solid microstructure of chip-based Al–Cu–Mn–Ti alloy prepared by SIMA method

Modern Physics Letters B ◽

10.1142/s0217984920503856 ◽

2020 ◽

Vol 34 (33) ◽

pp. 2050385

Author(s):

Ye Wang ◽

Maoliang Hu ◽

Hongyu Xu ◽

Zesheng Ji ◽

Xuefeng Wen ◽

...

Keyword(s):

Process Parameters ◽

Ostwald Ripening ◽

Isothermal Holding ◽

Treatment Temperature ◽

Holding Time ◽

Isothermal Treatment ◽

Isothermal Process ◽

Semi Solid ◽

Average Size ◽

Relationship Of

A typical Al–Cu–Mn–Ti aluminum alloy chip was adopted to prepare semi-solid billets by a Strain-Induced Melt Activation (SIMA) method, and the effects of isothermal process parameters on the semi-solid microstructure evolution of the alloy were investigated in this work. The result showed that semi-solid billets with highly spheroidal and homogeneous fine grains could be prepared from chips by the SIMA method. With the increase of isothermal temperature, the finer and near-spherical grains are obtained, the grains coarsen and became ellipse at 903 K because of the coarsening mechanisms of coalescence and Ostwald ripening. The relationship of isothermal holding time and grains size followed the LSW theory well, and more spherical microstructure can be brought by prolonging the holding time until 3000 s. Thus, the optimal isothermal treatment temperature is 893 K and holding time is 3000 s, the corresponding average size and roundness of grains are 137 [Formula: see text]m and 1.108, respectively.

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Microstructural Evolution of Electromagnetically Stirred Al Alloy during Isothermal Reheating in Solid-Liquid Region

Materials Science Forum ◽

10.4028/www.scientific.net/msf.486-487.338 ◽

2005 ◽

Vol 486-487 ◽

pp. 338-341

Author(s):

Dock Young Lee ◽

Ki Bae Kim ◽

Do Hyang Kim

Keyword(s):

Continuous Casting ◽

Casting Speed ◽

Continuous Casting Machine ◽

Casting Machine ◽

Electromagnetic Stirring ◽

Al Alloy ◽

Liquid Region ◽

Α Phase ◽

Solid Liquid ◽

Holding Temperature

The effects of reheating in solid-liquid region on the microstructure of electromagnetically stirred Al alloy have been investigated. The billet of Al alloy was produced at a various casting speed from 200 to 500 mm/min in a continuous casting machine with an electromagnetic stirring device. The microstructure of the billet, which was isothermally reheated in a solid-liquid region during holding for from 0.5 to 15 min, was examined. The roundness and size of primary α phase of electromagnetic stirred Al alloy was measured according to the reheating time. The roundness of primary α phase was obtained a minimum during holding for from 3 to 7 min at a holding temperature of 584°C and was deteriorated at a longer reheating time due to a dominant coalescence. Also the spheroidization of primary α phase during reheating in solid-liquid region was significantly dependent on initial microstructure of the billet.

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