scholarly journals Effect of annealing temperature and time on recrystallization behavior of Mg-Gd-Y-Zn-Zr alloy

2021 ◽  
Author(s):  
Rui Han ◽  
Leichen Jia ◽  
Zhimin Zhang ◽  
Qiang Wang ◽  
Jianmin Yu ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Electron Backscatter Diffraction ◽  
Extrusion Direction ◽  
Annealing Treatment ◽  
Optical Microscope ◽  
Abnormal Growth ◽  
Annealing Conditions ◽  
Grain Distribution ◽  
Backscatter Diffraction ◽  
Zr Alloy

Abstract In this paper, the effect of annealing treatment on the microstructure and hardness of extruded Mg-9Gd-4Y-2Zn-0.5Zr alloy (wt. %) was discussed. The microstructure evolution of the alloy under different annealing conditions was studied by optical microscope (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD), and the variation of hardness was analyzed. With the increase of annealing temperature, the large deformed grains first break into small recrystallized grains. When the temperature continues to increase, the recrystallized grains grow abnormally with the precipitation of chain phase and the fragmentation of lamellar long-period stacking ordered (LPSO) phase. The alloy does not recrystallize at low temperature, and the recrystallized grains grow abnormally at high temperature. The increase of annealing time will also lead to abnormal growth of recrystallized grains. The texture gradually diffuses from the classical extrusion texture to the extrusion direction (ED). The results show that under the condition of 430 °C × 5h, the recrystallization volume of the alloy is the largest, the recrystallization grain distribution is uniform, and the hardness value is the highest.

scholarly journals Annealing Response of a Cold-Rolled Binary Al–10Mg Alloy

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 759
Author(s):  
Feng ◽  
Li ◽  
Huang ◽  
Huang
Keyword(s):  
Grain Boundaries ◽  
Annealing Temperature ◽  
Electron Backscatter Diffraction ◽  
Annealing Treatment ◽  
Deformation Bands ◽  
X Ray Diffraction ◽  
Β Phase ◽  
Large Size ◽  
Cold Rolled ◽  
Backscatter Diffraction

The effect of annealing temperature on microstructure and mechanical properties of a cold-rolled Al–10Mg alloy has been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and tensile testing. The results showed that supersaturated Mg precipitated along grain boundaries and deformation bands during annealing treatment and precipitation size and the concentration of solid solution Mg atoms increased with the rising of annealing temperature. When annealed at low temperature, accumulation and annihilation of dislocations were the primary way of recovery; as temperature increased to 300 °C, recrystallized grains were formed around the large size β phase through particle-stimulated nucleation. A high ultimate strength (550 MPa) and a middle ductility (14%) were obtained when the Al–10Mg alloy was annealed at 200 °C for 1 h. The abnormal decrease of elongation when the Al–10Mg alloy was annealed at 250–300 °C was due to the formation of a continuous network distribution of large size β phase particles along grain boundaries.

scholarly journals Microstructure Evolution and Mechanical Property Characterization of 6063 Aluminum Alloy Tubes Processed with Friction Stir Back Extrusion

JOM ◽  
2019 ◽  
Vol 71 (12) ◽  
pp. 4436-4444
Author(s):  
Suhong Zhang ◽  
Alan Frederick ◽  
Yiyu Wang ◽  
Mike Eller ◽  
Paul McGinn ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Microstructure Evolution ◽  
Electron Backscatter Diffraction ◽  
Deformation Gradient ◽  
Optical Microscope ◽  
Grain Structure ◽  
Frictional Heat ◽  
Friction Stir ◽  
Metal Extrusion ◽  
Backscatter Diffraction

Abstract Friction stir back extrusion (FSBE) is a technique for lightweight metal extrusion. The frictional heat and severe plastic deformation of the process generate an equiaxed refined grain structure because of dynamic recrystallization. Previous studies proved that the fabrication of tube and wire structures is feasible. In this work, hollow cylindrical billets of 6063-T6 aluminum alloy were used as starting material. A relatively low extrusion ratio allows for a temperature and deformation gradient through the tube wall thickness to elucidate the effect of heat and temperature on the microstructure evolution during FSBE. The force and temperature were recorded during the processes. The microstructures of the extruded tubes were characterized using an optical microscope, energy-dispersive x-ray spectroscopy, electron backscatter diffraction, and hardness testing. The process reduced the grain size from 58.2 μm to 20.6 μm at the inner wall. The microhardness of the alloy was reduced from 100 to 60–75 HV because of the process thermal cycle.

Comparison of Grain Structures and Textures in AA5754 Aluminum Alloy Sheets Processed by Room Temperature Rolling and Rolling with Liquid Nitrogen

2007 ◽  
Vol 558-559 ◽  
pp. 217-222 ◽  
Author(s):  
Hai Ou Jin ◽  
Pei Dong Wu ◽  
David J. Lloyd
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Electron Backscatter Diffraction ◽  
Optical Microscope ◽  
Grain Structure ◽  
Micro Hardness ◽  
Grain Structures ◽  
Room Temperature Rolling ◽  
The One ◽  
Backscatter Diffraction

Two AA5754 sheets have been processed by cold rolling with 83% thickness reduction, one at room temperature and another with liquid nitrogen as coolant. The sheets were subsequently annealed at 220-275°C for 1 hour. The development of grain structure and texture was studied by optical microscope, scanning electron microscopy (SEM), X-ray diffraction and electron backscatter diffraction (EBSD) in SEM, and the mechanical property by micro-hardness testing. It has been demonstrated that the as-rolled sheets have the same micro-hardness, but the grain structures and textures are very different. Compared to the sheet processed with liquid nitrogen, the one rolled at room temperature has stronger shear texture and finer grain structure.

Effects of Annealing Treatment on the Microstructure and Mechanical Properties of Magnesium Alloy Sheets

2013 ◽  
Vol 303-306 ◽  
pp. 2524-2527 ◽  
Author(s):  
Lei Wang ◽  
Guang Hui Min ◽  
Pan Pan Gao ◽  
Xin Ying Wang ◽  
Hua Shun Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Optical Microscope ◽  
Icosahedral Phase ◽  
Alloy Sheet ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray

The microstructure of magnesium alloy sheets (nominal composition Mg–6Zn–Y in at. %) was investigated with the Optical Microscope (OM), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) technique after the annealing treatment. Tensile test at room temperature was performed to show the influence of annealing treatment on mechanical properties. Experimental results indicate that there are a large number of twin crystals appearing in microstructure of the extruded Mg-Zn-Y alloy sheet at 350 °C. The distinct icosahedral phase appears on the α-Mg matrix in granular form and the strength gets largely improved to the maximum. The uniform distribution of isometric crystal contributes to the best elongation at the annealing temperature of 400 °C.

scholarly journals Cryogenic Deformation Behavior and Microstructural Characteristics of 2195 Alloy

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1406
Author(s):  
Jin Zhang ◽  
Wenfu Tan ◽  
Cheng Wang ◽  
Chunnan Zhu ◽  
Youping Yi
Keyword(s):  
Electron Microscope ◽  
Electron Backscatter Diffraction ◽  
Underlying Mechanism ◽  
Optical Microscope ◽  
W State ◽  
Grain Structure ◽  
Cryogenic Deformation ◽  
Transmission Electron ◽  
Strength And Plasticity ◽  
Backscatter Diffraction

Cryogenic deformation can improve the strength and plasticity of Al–Li alloy, although the underlying mechanism is still not yet well understood. The effects of cryogenic temperature on the tensile properties and microstructure of an Al–Cu–Li alloy were investigated by means of tensile property test, roughness measurement, scanning electron microscope (SEM), optical microscope (OM), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM). The results indicated that the strength and elongation of the as-annealed (O-state) and solution-treated (W-state) alloys increased with the decrease in deformation temperature, where the increasing trend of elongation of the W-state alloy was more significant than that of the O-state alloy. In addition, a temperature range was observed at approximately 178 K that caused the strength of the W-state alloy to slightly decrease. The decrease in temperature inhibited the dynamic recovery of the Al–Cu–Li alloy, which increased the dislocation density and the degree of work hardening, thus improving the strength of the alloy. At cryogenic temperatures, the internal grain structure was more involved in the deformation and the overall deformation was more uniform, which caused the alloy to have higher plasticity. This study provides a theoretical basis for the cryogenic forming of Al–Li alloy.

scholarly journals Influence of Continuous Annealing Temperature on Mechanical Properties and Texture of Battery Shell Steel

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 52 ◽  
Author(s):  
Beijia Ning ◽  
Zhengzhi Zhao ◽  
Zhiying Mo ◽  
Hong Wu ◽  
Chong Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
Electron Backscatter Diffraction ◽  
Continuous Annealing ◽  
Normal Anisotropy ◽  
Fracture Elongation ◽  
Anisotropy Index ◽  
R Value ◽  
Backscatter Diffraction ◽  
Annealing Experiments

To study the influences of continuous annealing temperature on microstructure, mechanical properties and textures of battery shell steel, continuous annealing experiments were conducted at 710 °C, 730 °C, 760 °C and 780 °C respectively. The mechanical properties and normal anisotropy index (r) were measured by tensile test and the textures were investigated using the method of electron backscatter diffraction (EBSD). The results show that as annealing temperature rose, the grain size, fracture elongation and r value increased, whereas the strength and yield ratio decreased. The yield strength was 122 MPa, the tensile strength was 286 MPa, meanwhile the elongation and r value arrived at 38.8% and 2.3 when the annealing temperature rose to 780 °C. After annealing, the main texture in battery shell steel is {111} <112>, followed by {111} <110>. With the increase of annealing temperature, textures in {001} crystallographic plane weakened while textures in {111} plane strengthened, which is beneficial to the deep drawability of the steel.

Aqueous Corrosion of Deformed Steel Under Simulated Diluted Bitumen

CORROSION ◽  
10.5006/3121 ◽  
2019 ◽  
Vol 75 (10) ◽  
pp. 1194-1206
Author(s):  
Hongxing Liang ◽  
Rebecca Filardo Schaller ◽  
Edouard Asselin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Electron Backscatter Diffraction ◽  
Pipeline Steel ◽  
Optical Microscope ◽  
Circular Ring ◽  
Aqueous Corrosion ◽  
Backscatter Diffraction ◽  
Scanning Electron

The effect of predeformation on corrosion of ASTM A106B pipeline steel exposed to 1.7 mM sodium chloride droplets covered by simulated diluted bitumen was evaluated. The microstructures of ASTM A106B pipeline steel with and without predeformation were examined by electron backscatter diffraction and optical microscope. Corrosion of pipeline steel under the chloride droplet covered by simulated diluted bitumen for 5 min was studied with and without predeformation using scanning electron microscopy. Corrosion was initiated at the surface of ASTM A106B pipeline steel after 5 min of exposure. The predeformation increased the number of pits initiated at the steel surface and the number of partially dissolved inclusions. Scanning electron microscopy, profilometry, and x-ray photoelectron spectroscopy measurements were used to characterize the corrosion of the specimens with and without prior deformation after 24 h of exposure to an oil-covered droplet. The corrosion products coalesced and formed a small circular ring which deviated from the geometric center of the droplet. The diameters of the circular rings for the unbent and pre-bent specimens were 2.371±0.125 mm and 2.465±0.046 mm, respectively; the distances between the circular ring centers and droplet centers were 0.599±0.124 mm and 0.620±0.190 mm, respectively. The average corrosion penetration of the predeformed specimen was 1.18±0.09 times higher than that of the specimen without predeformation.

Microstructures and Properties of Aluminum Alloys during Repetitive Continuous Extrusion Forming

2016 ◽  
Vol 879 ◽  
pp. 2261-2267 ◽  
Author(s):  
Xian Kun Ji ◽  
Jia Min Hu ◽  
Hui Zhang ◽  
Fu Lin Jiang ◽  
Ding Fa Fu
Keyword(s):  
Tensile Testing ◽  
Electron Backscatter Diffraction ◽  
Optical Microscope ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Continuous Extrusion ◽  
Extrusion Forming ◽  
Backscatter Diffraction ◽  
Strength And Ductility

Repetitive continuous extrusion forming was employed as a continuous severe plastic deformation route and both Al-Fe-Cu alloy and Al-Mg-Si alloy were involved. Evolution of microstructures and properties during this process is investigated by optical microscope, electron-backscatter diffraction, transmission electron microscope, and tensile testing. The results show that in the Al-Fe-Cu alloy an obvious mechanical softening and grain refinement were observed, while in the Al-Mg-Si alloy it shows a slightly rising in strength and ductility as the extrusion passes increasing.

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