scholarly journals Evolution of Microstructure and Mechanical Properties of Mg-6Al Alloy Processed by Differential Speed Rolling upon Post-Annealing Treatment

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 926
Author(s):  
Honglin Zhang ◽  
Zhigang Xu ◽  
Sergey Yarmolenko ◽  
Laszlo J. Kecskes ◽  
Jagannathan Sankar
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
Mechanical Response ◽  
Rolling Direction ◽  
Rolled Plate ◽  
Speed Ratio ◽  
Roll Temperature ◽  
Basal Pole ◽  
Differential Speed Rolling ◽  
Differential Speed

Magnesium-6 wt.% aluminum (Mg-6Al) alloy plates with a 6-millimeter thickness were processed from an initial 12-millimeter thickness by differential speed rolling (DSR), with a 0.76-millimeter thickness reduction per pass using a speed ratio of 2, preheating temperature of 315 °C, and roll temperature of 265 °C. The effects of annealing temperature of 250, 275, and 300 °C with a corresponding holding time of 15 min on the microstructure, texture, and mechanical properties were investigated. Key results show that dynamic recrystallization (DRX) occurred during the roll processing, resulting in a greatly reduced grain size. In addition, the basal pole of the as-rolled plate was inclined to the rolling direction (RD) by ~20°, due to the shear strain introduced during DSR. Subsequent annealing caused grain growth, eliminated the basal pole inclination towards the RD, and slightly increased the pole intensity. Compared with the as-rolled plate, the average of the ultimate tensile strength (UTS) and the yield strength (YS) of the annealed plates decreased, while the average elongation at fracture (εf) increased. With the annealing temperature of 275 °C, the plate achieved a good combination of mechanical properties with UTS, YS, and εf being 292.1 MPa, 185.0 MPa, and 24.9%, respectively. These results suggest that post-roll annealing is an effective way to improve the mechanical response of this Mg alloy processed by DSR.

Influences of Rolling Conditions on Texture and Mechanical Properties of AZ31 Magnesium Alloy Processed by Differential Speed Rolling

2007 ◽  
Vol 561-565 ◽  
pp. 287-290
Author(s):  
Kazutaka Suzuki ◽  
Xin Sheng Huang ◽  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
Naobumi Saito
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Rolling Direction ◽  
Rolling Temperature ◽  
Az31 Magnesium Alloy ◽  
Speed Ratio ◽  
Shear Direction ◽  
Differential Speed Rolling ◽  
Press Formability ◽  
Differential Speed

It was reported that the cold and warm press formability of the magnesium alloy was improved by the application of a differential speed rolling (DSR). However, it can be considered that the microstructure and the texture of the DSR processed sheets greatly change with the rolling conditions. In this study, commercial AZ31B magnesium alloy extrusions were processed by DSR at a differential speed ratio of 1.167 and a reduction per pass of 10% or less, and the effects of the rolling temperature, the number of rolling passes and reversal of the rolling direction on texture and mechanical properties were examined. As a result, it was found that the optimal rolling temperature in terms of the workability and formability of the material was 573 K. And the elongation and formability were maximal in sheets processed by 4–6 passes of DSR. Moreover, reversing the shear direction made the microstructure more homogeneous and finer than unidirectional shear, and improved the mechanical properties and formability. This improvement was greater in samples where the shear direction was reversed once in the middle than where it was reversed for each pass.

Effects of Differential Speed Rolling on Microstructure and Mechanical Properties of AZ31 Magnesium Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 1759-1763 ◽  
Author(s):  
Xin Sheng Huang ◽  
Kazutaka Suzuki ◽  
Yong Jai Kwon ◽  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Bands ◽  
Rolling Direction ◽  
Az31 Alloy ◽  
Speed Ratio ◽  
Rolled Sheet ◽  
Proof Stress ◽  
Tensile Direction ◽  
Differential Speed Rolling ◽  
Differential Speed

A differential speed rolling (DSR) processing with a roll speed ratio of 1.167 was carried out on an AZ31 alloy for investigating the effects of DSR on microstructure, texture and mechanical properties. The DSR processed sheet showed unidirectional shear bands with a small grain size of 5.5 μm inclining to the rolling direction, and the basal plane tended to incline at about 15º from the rolling plane toward the rolling direction. Compared with the normal rolled sheet, the DSR processed sheets showed a lower proof stress and a larger elongation with an increase from 21% to 26% in the rolling direction. The proof stress increased and the elongation decreased with the angle between the tensile direction and the rolling direction.

scholarly journals Microstructure, Texture and Mechanical Properties of Mg-6Sn Alloy Processed by Differential Speed Rolling

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 83
Author(s):  
Kamil Majchrowicz ◽  
Paweł Jóźwik ◽  
Witold Chromiński ◽  
Bogusława Adamczyk-Cieślak ◽  
Zbigniew Pakieła
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Rolling Direction ◽  
Speed Ratio ◽  
Basal Texture ◽  
Electron Backscattered Diffraction ◽  
Normal Anisotropy ◽  
Average Grain Size ◽  
Differential Speed Rolling ◽  
Differential Speed

The effect of shear deformation introduced by differential speed rolling (DSR) on the microstructure, texture and mechanical properties of Mg-6Sn alloy was investigated. Mg-6Sn sheets were obtained by DSR at speed ratio between upper and lower rolls of R = 1, 1.25, 2 and 3 (R = 1 refers to symmetric rolling). The microstructural and textural changes were investigated by electron backscattered diffraction (EBSD) and XRD, while the mechanical performance was evaluated based on tensile tests and calculated Lankford parameters. DSR resulted in the pronounced grain refinement of Mg-6Sn sheets and spreading of basal texture as compared to conventionally rolled one. The average grain size and basal texture intensity gradually decreased with increasing speed ratio. The basal poles splitting to transverse direction (TD) or rolling direction (RD) was observed for all Mg-6Sn sheets. For the as-rolled sheets, YS and UTS increased with increasing speed ratio, but a significant anisotropy of strength and ductility between RD and TD has been observed. After annealing at 300 °C, Mg-6Sn sheets became more homogeneous, and the elongation to failure was increased with higher speed ratios. Moreover, the annealed Mg-6Sn sheets were characterized by a very low normal anisotropy (0.91–1.16), which is normally not achieved for the most common Mg-Al-Zn alloys.

scholarly journals Effect of Grain Refinement and Dispersion of Particles and Reinforcements on Mechanical Properties of Metals and Metal Matrix Composites through High-Ratio Differential Speed Rolling

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4159 ◽  
Author(s):  
Ahmad Bahmani ◽  
Woo-Jin Kim
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
High Speed ◽  
Large Scale ◽  
High Ratio ◽  
Speed Ratio ◽  
Matrix Composites ◽  
Differential Speed Rolling ◽  
Differential Speed

A differential speed rolling (DSR) technique that provides capability of producing large-scale materials with fine grains and controlled texture in a continuous manner has attracted several researchers and industries. In this study, we tried to review the articles related to DSR and especially the high-ratio DSR (HRDSR) technique that is associated with a high speed ratio between the upper and lower rolls (≥2) and compare the change in microstructure and mechanical properties after HRDSR with the results obtained by using other severe plastic deformation (SPD) techniques to see the potential of the HRDSR technique in enhancing the mechanical properties of metals and metal matrix composites. The reviewed results show that HRDSR is an important technique that can effectively refine the grains to micro or nano sizes and uniformly disperse the particles or reinforcement throughout the matrix, which helps extensively in improving ambient and superplastic mechanical properties of various metals and alloys.

Microstructure and Texture Control of Al-Mg Alloy Sheets by Differential Speed Rolling

2005 ◽  
Vol 495-497 ◽  
pp. 597-602 ◽  
Author(s):  
Tetsuo Sakai ◽  
K. Yoneda ◽  
S. Osugi
Keyword(s):  
Shear Strain ◽  
Shear Deformation ◽  
Rolling Direction ◽  
Deformation Texture ◽  
Speed Ratio ◽  
Roll Speed ◽  
Shear Texture ◽  
Differential Speed Rolling ◽  
R Value ◽  
Differential Speed

Large shear deformation was successfully introduced in 5182 aluminum alloy sheets by 2-pass differential speed warm rolling under a high friction condition. The roll speed ratio was varied from 1.0 to 2.0. When the roll speed ratio was smaller than 1.4, shear strain increased near the surface, but the strain decreased to zero at the mid-thickness. At a roll speed ratio larger than 1.4, shear strain was introduced even at the mid-thickness, and it increased near the surface. Thus the shear strain increased with the roll speed ratio. After 2-pass differential speed rolling, a large shear strain prevailed throughout the thickness. The rolling direction of the second pass was so selected that the direction of shear deformation introduced in the second pass was similar to (unidirectional shear rolling) or opposite (reverse shear rolling) that in the first pass. A shear texture with main components of {111}<110>, {112}<110> and {001}<110> prevailed throughout the thickness, and conventional rolling textures such as {112}<111> or {123}<634> orientation were not detected in any part of thickness. The rolling direction of the second pass had little effect on the deformation texture. After recrystallization annealing, the shear texture components were retained. The intensity of the shear texture components after recrystallization was almost similar to the deformation texture. The r-value of the annealed sheet was slightly increased and the planar anisotropy of the r-value was decreased by differential speed rolling. Differential speed rolling, by which shear deformation can be introduced throughout the thickness, was thus shown to be a promising process for improving the physical and mechanical properties of rolled and annealed aluminum alloy sheets by texture control.

Mechanical Properties and Formability of AZ31 Magnesium Alloy Processed by Differential Speed Rolling

2007 ◽  
Vol 544-545 ◽  
pp. 395-398 ◽  
Author(s):  
Xin Sheng Huang ◽  
Kazutaka Suzuki ◽  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
Naobumi Saito
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Rolling Plane ◽  
Alloy Sheet ◽  
Speed Ratio ◽  
Roll Speed ◽  
Proof Stress ◽  
Differential Speed Rolling ◽  
R Value ◽  
Differential Speed

An AZ31 (Mg-3Al-1Zn-0.35Mn in mass%) alloy sheet exhibiting the inclination of the basal plane from the rolling plane at about 15º, was fabricated by a DSR processing with a roll speed ratio of 1.167. Compared with the normal rolled sheets, the DSR processed sheets showed a lower 0.2% proof stress, a larger elongation, a smaller r-value and a larger n-value. The Erichsen value at room temperature significantly increased from 2.2 to 3.1, and the deep drawability also improved.

Microstructures and Mechanical Properties of Nano-Structured Aluminum Fabricated by Accumulative Roll-Bonding Using Different Rolling Methods

2006 ◽  
Vol 317-318 ◽  
pp. 327-330 ◽  
Author(s):  
Seong Hee Lee ◽  
Tetsuo Sakai ◽  
Chung Hyo Lee ◽  
Yong Ho Choa
Keyword(s):  
Mechanical Properties ◽  
Accumulative Roll Bonding ◽  
The Other ◽  
Speed Ratio ◽  
Roll Speed ◽  
Roll Bonding ◽  
Differential Speed Rolling ◽  
Processed Sample ◽  
Conventional Rolling ◽  
Differential Speed

Nano-structured aluminum was fabricated by accumulative roll-bonding (ARB) process using different rolling methods. One is the ARB using conventional rolling (CR) in which the speed of two rolls (3.0m/min) was equal to each other. The other is the ARB using differential speed rolling (DSR) in which the speed of two rolls is different to each other. The roll peripheral speed of one roll was 2.0m/min and that of another roll was 3.6m/min. The roll speed ratio was kept at 1.8. The ARB was conducted up to 6 cycles at ambient temperature without lubrication. In both cases, the ultrafine grains were developed in the samples. The grains formed by the DSR-ARB were more equiaxed and finer than those produced by the CR-ARB. Tensile strength of the DSR-ARB processed sample was superior to that of the CR-ARB processed one. The elongation was not affected significantly by the number of ARB cycles in both cases. Texture analysis demonstrated that the shear strain, in the case of DSR-ARB, was introduced into the center of thickness. It was concluded that the DSR-ARB process was more effective for grain refinement and strengthening than the CR-ARB process.

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