Ultrafine grain formation in Mg–Zn alloy by in situ precipitation during high-pressure torsion

Meng, Fanqiang; Rosalie, Julian M.; Singh, Alok; Somekawa, Hidetoshi; Tsuchiya, Koichi

doi:10.1016/j.scriptamat.2014.01.036

Cited by 58 publications

(30 citation statements)

References 21 publications

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“…Increased width of stacking faults makes dislocation cross-slip and climb more difficult, which makes dynamic recovery slow and difficult, leading to an increased dislocation density and high strain hardening effect in the first several HPT turns. In previous work on SPD processing of Mg alloys, often a solution treatment was conducted before SPD [11,12,40], whereas in this study HPT was performed on the as-cast Mg-Gd-Y-Zn-Zr alloy containing LPSO and Mg3(Gd,Y) phases. The dislocations will pile up at these second phases in grain interiors and at grain boundaries, i.e.…”

Section: Discussionmentioning

confidence: 99%

Evolution of microstructure and mechanical properties of an as-cast Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy processed by high pressure torsion

Sun

Qiao

et al. 2017

Materials Science and Engineering: A

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Abstract:The novel Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy with high content of rare earth elements has been processed successfully by high pressure torsion (HPT) starting from an as-cast condition. HPT processing was conducted at room temperature for a range of turns from 1/8 to 16, and the evolutions of microstructure and microhardness were investigated.The average grain size decreases from ~85 μm in the as-cast condition to ~55 nm when the equivalent strain reaches ~6.0, and remains almost constant on further strain increase. Meanwhile, the coarse netlike Mg3(Gd,Y) second phase structures are gradually broken into fine dispersed particles and the dislocation density increases. The microhardness of the alloy increases with increasing strain, and when the equivalent strain reaches ~6.0, the microhardness reaches a saturated value of about 115 HV, which is higher than that obtained by conventional extrusion / rolling of this alloy. The full range of possible mechanisms of hardening are analysed and this reveals that hardening is primarily due to the pronounced grain refinement, which is substantially 2 stronger than that for HPT-processed conventional Mg alloys, and to the homogeneously distributed fine second phase particles and the high dislocation density.

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Section: Discussionmentioning

confidence: 99%

Evolution of microstructure and mechanical properties of an as-cast Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy processed by high pressure torsion

Sun

Qiao

et al. 2017

Materials Science and Engineering: A

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“…The discs were deformed for 3 revolutions (to reach the maximum hardness condition [11]) at room temperature using high-pressure torsion apparatus with a pressure of 5 GPa and rotation speed of 1 rpm (revolution per minute). Annealing treatment was performed in an oil bath with temperature of 348 and 423 K for various times.…”

Section: Methodsmentioning

confidence: 99%

“…The HPT technique can also be used to process or prepare the materials with hexagonal close packed (HCP) crystalline structures [9], which have poor ductility and crack easily due to the lack of slip systems at room temperature. Recently, a crack-free UFG structure was successfully fabricated by HPT at room temperature in pure Mg and MgZn alloys [10,11].…”

Section: Introductionmentioning

confidence: 99%

Precipitation behavior of an ultra-fine grained Mg–Zn alloy processed by high-pressure torsion

Meng¹,

Rosalie²,

Singh³

et al. 2015

Materials Science and Engineering: A

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“…In the other hand, metallic materials with nanometric grain sizes can attain superior mechanical properties than those with coarse grained [4][5][6][7][8] . However, processing techniques that involve work hardening improve physical properties as strength, typically achieved at the expense of ductility 9 .…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Microstructural Characterization and Microhardness of AlCoNi-SiC Composite Prepared by Mechanical Alloying

et al. 2017

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Equiatomic AlCoNi alloy matrix were reinforced by the dispersion of SiC nanoparticles (SiCnp) using the mechanical alloying process. The metallic powders were milled for 10, 20 and 30 h and sintered at 1200 0C under vacuum. Through particle size distribution, X-ray diffraction and scanning electron microscopy investigations, the mechanically alloyed powders for 10 h were selected to be reinforced with SiCnp (2.5, 5 and 10 wt.%). The microstructural features, and improvement in microhardness and porosity of sintered AlCoNi-SiC composites were investigated as a function of SiCnp content. Microhardness Vickers test showed that the enhanced microhardness of the AlCoNi-SiCnp composite could be attributed to the decrease of porosity in comparison to the AlCoNi alloy.

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Ultrafine grain formation in Mg–Zn alloy by in situ precipitation during high-pressure torsion

Cited by 58 publications

References 21 publications

Evolution of microstructure and mechanical properties of an as-cast Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy processed by high pressure torsion

Evolution of microstructure and mechanical properties of an as-cast Mg-8.2Gd-3.8Y-1.0Zn-0.4Zr alloy processed by high pressure torsion

Precipitation behavior of an ultra-fine grained Mg–Zn alloy processed by high-pressure torsion

Synthesis, Microstructural Characterization and Microhardness of AlCoNi-SiC Composite Prepared by Mechanical Alloying

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