Grain Refinement in Undercooled Metals

1997 ◽  
Vol 481 ◽  
Author(s):  
J. Z. Xiao ◽  
H. Yang ◽  
H. W. Kui
Keyword(s):  
Grain Refinement ◽  
Microstructural Analysis ◽  
Refinement Process ◽  
Bulk Undercooling ◽  
Dynamic Nucleation

ABSTRACTRecently, it was demonstrated that grain refinement in metals can take place through two mechanisms, namely, dynamic nucleation and remelting of initially formed dendrites. In this study, it was found that Ni99.45B0.55 undergoes grain refinement, both by dynamic nucleation or by remelting, depending on the initial bulk undercooling just before crystallization. The nature of the grain refinement process is confirmed by microstructural analysis of the undercooled specimens.

scholarly journals Grain Refinement by Extension Twin in Mg Alloy during Asymmetrical Rolling

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 891 ◽  
Author(s):  
I Widiantara ◽  
Hae Yang ◽  
Muhammad Kamil ◽  
Dong Yoon ◽  
Young Ko
Keyword(s):  
Grain Refinement ◽  
Electron Backscatter Diffraction ◽  
Surface Region ◽  
Mg Alloy ◽  
Speed Ratio ◽  
Asymmetrical Rolling ◽  
Present Sample ◽  
Refinement Process ◽  
Backscatter Diffraction

The work looked into the grain refinement process of Mg alloy during asymmetrical rolling with a focus on the role of twin. The present sample was deformed at ambient temperature by single operation with the height reduction of 50% at the roll speed ratio of 1:4 for the upper and lower rolls having the same dimension. From the electron backscatter diffraction analysis in the surface region where intense shear strain was imparted, a number of { 10 1 ¯ 2 } extension twins with a width of ~1 µm were detected clearly in most of the deformed grains. Moreover, the average misorientation angle of the deformed grains in the top region was found to be ~32°, which was two times higher than that in the center area where the extension twin was detected rarely. As a result, the microstructure in the top region was refined significantly down to be ~1.1 µm with an aid of twin activities that would be discussed in this study.

A Recrystallisation Based Investigation for Efficiency of Processing Routes during Equal Channel Angular Extrusion

2004 ◽  
Vol 467-470 ◽  
pp. 1325-1332 ◽  
Author(s):  
Satyam Suwas ◽  
André Eberhardt ◽  
László S. Tóth ◽  
Jean-Jacques Fundenberger ◽  
Thierry Grosdidier
Keyword(s):  
Differential Scanning Calorimetry ◽  
Grain Refinement ◽  
Equal Channel Angular Extrusion ◽  
Cold Work ◽  
Stacking Fault ◽  
Stored Energy ◽  
Scanning Calorimetry ◽  
Angular Extrusion ◽  
Refinement Process ◽  
Stacking Fault Energies

The amount of stored energy of cold work for the processing routes A and Bc of Equal Channel Angular Extrusion (ECAE) process has been measured using differential scanning calorimetry. The study is preceded by the effect of amount of ECAE deformation on materials of different stacking fault energies, namely Cu and Ag. The results indicate that the different processing routes have significant effect on the stored energy, which is likely to affect the grain refinement process.

Grain refinement process in a cold-rolled polycrystalline cobalt

2020 ◽  
Vol 164 ◽  
pp. 110360 ◽  
Author(s):  
Xinglong An ◽  
Yan Li ◽  
Song Ni ◽  
Zhangwei Wang ◽  
Min Song
Keyword(s):  
Grain Refinement ◽  
Refinement Process ◽  
Cold Rolled

Grain refinement process for Al-containing magnesium alloys

2014 ◽  
Vol 52 (12) ◽  
pp. 975-982 ◽  
Author(s):  
Jun Ho Bae ◽  
Young Min Kim ◽  
Bong Sun You
Keyword(s):  
Grain Refinement ◽  
Magnesium Alloys ◽  
Refinement Process

Grain Refinement and Mechanism of Carbon Inoculation in Mg-Al Magnesium Alloys

2014 ◽  
Vol 788 ◽  
pp. 98-102 ◽  
Author(s):  
Zhao Hui Wang ◽  
Xiao Long Zhang ◽  
Shu Bo Li ◽  
Ke Liu ◽  
Wen Bo Du
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Graphite Powder ◽  
Microstructure And Mechanical Properties ◽  
Refinement Process ◽  
Carbon Inoculation

Grain refinement is important for improving the microstructure and mechanical properties of magnesium alloys. Carbon inoculation is an effective method of grain refinement process for magnesium alloys containing aluminum. In this paper, the C2Cl6 and graphite powder were used as the potential grain refiners for AM60 and AZ91 alloys, respectively. The results show that the microstructure and mechanical properties of these Mg-Al magnesium alloys have been improved with these grain refiners. The mechanism and thermodynamics analyses of grain refinement with carbon inoculation in Mg-Al magnesium alloy have been discussed.

Study of Grain Refinement and SiC Nanoparticle Reinforced Magnesium Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 889-892 ◽  
Author(s):  
Zhao Hui Wang ◽  
Yong Lin Kang ◽  
Wenchao Dong ◽  
Hongjin Zhao ◽  
Jin Wei Liu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Sic Nanoparticles ◽  
Specific Strength ◽  
High Specific Strength ◽  
Refinement Process ◽  
Reinforced Process ◽  
Strength And Ductility

Magnesium alloys offer advantages of low density, high specific strength, machinability and availability. So it has been used more and more in many fields, such as automobile, communication etc. In this paper, grain refinement process and SiC nanoparticles reinforcement process are investigated for the purposes of increasing ultimate tensile strengthen and ductility of AM60B magnesium alloys. We find that after grain refinement process the ultimate tensile strength of AM60B alloys with permanent casting increase to 241MPa, which is about 27MPa higher than that of original alloys, and the elongation of it increases up to 20.1%, which is about 8.7% higher than that of original alloys. We added SiC nanoparticle into AM60B alloys in liquid state and found it could increase strength and ductility of alloys. By SiC nanoparticle reinforced process the ultimate tensile strength of magnesium alloys can increase up to 255MPa with the elongation of 19%.

Grain Refinement Mechanisms Oterative during Equal Channel Angular Pressing of Aluminium

2011 ◽  
Vol 702-703 ◽  
pp. 135-138
Author(s):  
Rampada Manna ◽  
N.K. Mukhopadhyay ◽  
G.V.S. Sastry
Keyword(s):  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Lattice Rotation ◽  
Recrystallization Process ◽  
Continuous Dynamic Recrystallization ◽  
Angular Pressing ◽  
Subgrain Formation ◽  
Refinement Process ◽  
Continuous Dynamic

Grain refinement of aluminum deformed by equal channel angular pressing is strongly dependent on the amount of strain. The refinement process at low to high strain level involves elongation of the existing grains by shear deformation, their subdivision into bands and subgrain formation within bands, intersection of the bands during subsequent passes and finally conversion of the subgrains to grains by continuous dynamic recrystallization process. At room temperature the conversion of subgrains to grains takes place by progressive lattice rotation.

Grain Refinement Process in Aluminium Alloys Type AlZnMgZr

2006 ◽  
pp. 224-232 ◽  
Author(s):  
Tomasz Stuczyński ◽  
Marzena Lech-Grega
Keyword(s):  
Grain Refinement ◽  
Aluminium Alloys ◽  
Refinement Process
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