scholarly journals Microstructure, Texture Evolution, and Mechanical Properties of MDFed GWZ Alloy Containing LPSO Phases on the Condition of High and Low Temperature Cycle Deformation

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 136 ◽  
Author(s):  
Dong ◽  
Zhang ◽  
Che ◽  
Yu ◽  
Meng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Texture Evolution ◽  
Annealing Treatment ◽  
Tensile Yield Strength ◽  
Temperature Cycle ◽  
Basal Texture ◽  
Homogeneous Microstructure ◽  
Homogenization Treatment ◽  
Average Grain Size

The current work systematically investigated the microstructure, texture evolution, and mechanical properties of MDFed Mg-13Gd-4Y-2Zn-0.5Zr (wt%) alloy (GWZ) on the condition of high and low temperature cycle deformation. The high and low temperature cycle deformation was proposed on the basis of the conventional multi-directional forging (MDF) at decreasing temperature and annealing treatment. As a new method, it was aimed to timely uniform the microstructure and strengthen magnesium (Mg) matrix during the deformation process. A low accumulative strain of 3 after 1 pass resulted in a bimodal microstructure with undynamic recrystallized (unDRXed) regions and dynamic recrystallized (DRXed) grains, while a high accumulative strain of 12 after 4 passes lead to a homogeneous microstructure with fine DRXed grains. According to the experimental results, it indicated that the average grain size of 63 μm after homogenization treatment at 520 was refined remarkably to 5.20 μm after 4 passes at 420 °C through high and low temperature cycle deformation. The area fraction of DRXed grains was increased to 98.4%, which can be regarded as achieving complete DRX after 4 passes. The grain refinement was mainly caused by particle stimulation nucleation (PSN) and mechanism. As the MDF passes and accumulative strain increased, the basal texture was weakened and transformed from a strong basal texture to a random distribution gradually. Compared with conventional MDF at decreasing temperature, the mechanical properties were enhanced effectively. After 4 passes, the ultimate tensile strength (UTS), tensile yield strength (TYS), and failure elongation (FE) were 405 MPa, 305 MPa, and 13.1%, respectively.

Microstructure and Mechanical Properties of Commercial Purity HIPed and Crushed Aluminum

2008 ◽  
Vol 584-586 ◽  
pp. 579-584 ◽  
Author(s):  
Quang Hien Bui ◽  
Guy F. Dirras ◽  
A. Hocini ◽  
Salah Ramtani ◽  
Akrum Abdul-Latif ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Mechanical Response ◽  
Texture Evolution ◽  
Hot Isostatic Pressing ◽  
Commercial Purity ◽  
Homogeneous Microstructure ◽  
Average Grain Size ◽  
Average Size ◽  
The Impact

Ultrafine-grained aluminum microstructures were processed from commercial purity powder by combining hot isostatic pressing (HIP) and dynamic severe plastic deformation (DSPD). After the first step, the bulk consolidated material showed a random texture and homogeneous microstructure of equiaxed grains with an average size of 2µm. The material was then subsequently impacted, using a falling weight at a strain rate of 300s-1. The resulting material showed a microstructure having an average grain size of about 500 nm with a strong gradient of fiber-like crystallographic texture parallel to the impact direction. The mechanical properties of the impacted material were subsequently characterized under compressive tests at room temperature at a strain rate of 10-4s-1. The effect of the change of the deformation path on the mechanical response parallel (DN) and perpendicular (DT) to the impact direction was also investigated. These results are here discussed in relation with microstructure and texture evolution.

Microstructure, Mechanical Properties, Electric and Thermal Conductivity of the As-Extruded Al-x(1.0 wt.% Zn + 0.5 wt.% Cu) Alloys (x = 1, 2 and 4)

2020 ◽  
Vol 20 (7) ◽  
pp. 4248-4252
Author(s):  
Yong-Ho Kim ◽  
Hyo-Sang Yoo ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Intermetallic Compounds ◽  
Extrusion Process ◽  
Al Alloy ◽  
Homogenization Treatment ◽  
Solid Solution Strengthening ◽  
Cu Content ◽  
Average Grain Size ◽  
Solution Strengthening

In this research, effects of Zn and Cu content on microstructure, mechanical properties, electric and thermal conductivity of the as-extruded Al-x(Zn+0.5Cu) alloys were investigated. As the content of Zn and Cu increased, the area ratio of Al2Cu intermetallic compounds increased. After homogenization treatment and extrusion process, most of Al2Cu intermetallic compounds was disappeared due to solution in Al matrix of Cu atoms. As the (Zn+0.5Cu) content increased from 1 to 2 wt.%, the average grain size decreased remarkably from 645 to 227 μm due to the dynamic recrystallization caused by the solute Zn and Cu atoms during the extrusion. With increasing Zn and Cu additions, the thermal conductivity was decreased from 225 (x = 1) to 208 (x = 2) and 183 W/mK (x = 4) due to electric scattering by solute Zn and Cu atoms. The ultimate tensile strength (UTS) of the as-extruded Al-x(1Zn+0.5Cu) alloys improved remarkably from 77 (x = 1) to 142 MPa (x = 4) as Zn and Cu content increased, and the elongation increased from 30 to 33%. This improvement in the strength resulted from the grain refinement and solid solution strengthening due to the solute Zn and Cu atoms. The Zn and Cu addition in Al alloy played an important role in thermal conductivity and mechanical properties.

Mechanical Properties and Microstructures of Mg-Al-Zn Alloys with High Aluminum Contents

2009 ◽  
Vol 610-613 ◽  
pp. 801-805
Author(s):  
Xing Gang Li ◽  
Kui Zhang ◽  
Yong Jun Li ◽  
Xin Zhao ◽  
Xu Jun Mi
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Annealing Treatment ◽  
Hot Extrusion ◽  
Hardness Measurement ◽  
Eutectic Phase ◽  
Magnesium Matrix ◽  
Homogenization Treatment ◽  
Zn Alloys ◽  
High Aluminum

The effect of Al contents on the properties and structures of AZ80, AZ91，AZ131 and AZ151 magnesium alloys has been studied. The experiments of homogenization treatment, hot extrusion, and annealing treatment are carried out in order to study the effects of these processes to the properties and structure of AZ80, AZ91, AZ131 and AZ151 magnesium alloys. The parameters of homogenization treatment (420°C×24h, 420°C×36h) determined by DSC and metallurgical photo are sufficient which ensure the eutectic phase melt into magnesium matrix greatly. The strength of extruded bars shortly after homogenization treatment increase (Rp0.2 from 232 to 310MPa), but elongation decrease (A from 12 to 2.5%) with Al contents. The differences and causes of structure and mechanical properties of extruded bar after the process of aging are analyzed in detail by tensile experiments, hardness measurement, and optical observation.

Enhancement of ductility in Mg–3Al–1Zn alloy with tilted basal texture by electropulsing

2009 ◽  
Vol 24 (12) ◽  
pp. 3674-3679 ◽  
Author(s):  
Lei Guan ◽  
Guoyi Tang ◽  
Paul K. Chu ◽  
Yanbin Jiang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Tensile Ductility ◽  
Texture Evolution ◽  
Boundary Motion ◽  
Basal Texture ◽  
Rolled Sample ◽  
Cold Rolled ◽  
Electropulsing Treatment ◽  
Grain Boundary Motion

The microstructure and texture evolution in a cold-rolled AZ31 magnesium alloy during electropulsing treatment (EPT) are investigated and correlated with the mechanical properties. The microstructure is effectively refined, and a tilted basal texture develops gradually during EPT. The yield stress in the treated samples is lower than that in the cold-rolled sample, indicating that texture softening is dominant over strengthening because of grain refinement. The phenomenon is primarily the result of the tilted basal texture. EPT improves the tensile ductility of the EPT samples significantly, albeit slightly compromising the tensile strength. The mechanism of the microstructure evolution during electropulsing is discussed from the viewpoint of grain-boundary motion. Moreover, the ductility enhancement is discussed in terms of the deformation mechanism and texture of the Mg alloy.

scholarly journals Effect of homogenization on microstructure evolution and mechanical properties of aged Mg-Nd-Sm-Zn-Zr alloy

2021 ◽  
Author(s):  
Tao Ma ◽  
Sicong Zhao ◽  
Liping Wang ◽  
Zhiwei Wang ◽  
Erjun Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Microstructure Evolution ◽  
Mechanical Performance ◽  
Cast Alloy ◽  
Homogenization Temperature ◽  
Aged Alloy ◽  
Homogenization Treatment ◽  
Β Phase ◽  
Average Grain Size

Abstract As an indispensable pre-treatment for aging, homogenization treatment has a significant effect on precipitation behavior of the Mg-RE alloys. Herein, the influence of homogenization temperature on the microstructure evolution and mechanical performance of a novel Mg-2.0Nd-2.0Sm-0.4Zn-0.4Zr (wt.%) alloy has been studied systematically. The results indicated that the as-cast alloy was mainly composed of α-Mg matrix, β-Mg12(Nd,Sm,Zn) phase and Zr-containing particles. Upon increasing the homogenization temperature from 500 oC to 525 oC for 8 h, the average grain size of as-homogenized alloy increased from 76 μm to 156 μm, and the content of β phase decreased gradually. It was worth noting that the homogenization temperature exceeded 515 oC, the β phase at the grain boundaries was completely dissolved. After aging at 200 oC for 18 h, numerous of plate-like β' phases were observed in α-Mg matrix. The rise in homogenization temperature was conducive to nucleation and growth of the β' phase. However, excessive homogenization temperature significantly coarsened grain size. The aged alloy under homogenization treatment at 515 oC for 8 h achieved optimal mechanical properties. The values of ultimate tensile strength, yield strength and elongation were 261 MPa, 154 MPa and 5.8 %, respectively. The fracture mode of the aged alloy mainly exhibited a typical transgranular cleavage fracture.

Microstructure and Mechanical Properties of Mg-6Al-0.3Mn-0.9Y Alloy

2012 ◽  
Vol 499 ◽  
pp. 44-48
Author(s):  
G.H. Su ◽  
Zhan Yi Cao ◽  
Xue Ran Liu ◽  
Y. Sun
Keyword(s):  
Mechanical Properties ◽  
Annealing Treatment ◽  
Annealed Sample ◽  
Test Results ◽  
Rolled Sample ◽  
Cast Sample ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Hot Rolled ◽  
Mould Casting

Mg-6Al-0.3Mn-0.9Y (mass fraction, %) magnesium alloy was prepared by metal mould casting. The as-cast ingot was homogenized, and then hot-rolled with total thickness reduction of 70%. Further annealing treatment was carried out on the hot-rolled sample. Microstructure and mechanical properties of the studied alloy in as-cast, hot rolled and annealed states were investigated. Results showed that main phases of the as-cast sample were composed of α-Mg, Mg17Al12 and Al2Y. Average grain size was about 9 μm after hot rolling and annealing treatment. It is found that the optimal annealed parameters for the Mg-6Al-0.3Mn-0.9Y alloy should be 350 °C for annealed temperature and 30 min for the corresponding time, respectively. Tensile test results showed that ultimate tensile strength, yield strength and elongation of the annealed sample were 261 MPa, 149 MPa and 32%, respectively. Compared with those of the as-cast sample, they were enhanced by 36%, 140% and 146% correspondingly.

scholarly journals Study on Microstructure Evolution and Mechanical Properties of Ti2AlNb-Based Alloy under Canning Compression and Annealing

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 980 ◽  
Author(s):  
Wang ◽  
Xu ◽  
Sun ◽  
Zong ◽  
Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Microstructure Evolution ◽  
Texture Evolution ◽  
Annealing Treatment ◽  
Deformation Degree ◽  
Height Reduction ◽  
Schmid Factor ◽  
B2 Phase ◽  
Recrystallized Grain Size

The influence of height reduction on the microstructure evolution and mechanical properties of the Ti2AlNb-based alloy was investigated during canning compression and subsequent annealing. After the annealing treatment, the spheroidized B2 phase grains occurred because of partial recrystallization. Meanwhile, the texture evolution of the B2 phase and O phase were analyzed under the deformation degree, ranging from 25% to 75%. The results show that the mechanical properties of the post-annealed alloys were co-affected by the grain size and Schmid factor of the B2 phase. When the height reduction was less than 25%, the compression strength was mainly affected by the grain size. When the height reduction was higher than 50%, it was mainly dominated by the Schmid factor. When the deformation degree reached 75%, the recrystallized grain size decreased to 0.9 μm. Meanwhile, the Schmid factor of a {110}<001> slip system in B2 phase reduced to 0.34. Therefore, the yield strength of the Ti2AlNb alloy at room temperature increased from 892 MPa in the as-rolled condition to 935 MPa after the canning compression and annealing.

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.

Production of Ti-6Al-4V Sheets for Low Temperature Superplastic Forming

2007 ◽  
Vol 551-552 ◽  
pp. 31-36 ◽  
Author(s):  
Gennady A. Salishchev ◽  
Oleg R. Valiakhmetov ◽  
Werner Beck ◽  
F.H. Froes
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Low Temperature ◽  
Sheet Material ◽  
Superplastic Forming ◽  
Sheet Plane ◽  
Initial Flow ◽  
Average Grain Size ◽  
Superplastic Properties ◽  
Commercial Size

The availability to produce Ti-6Al-4V sheet material with submicron-grained microstructure for superplastic forming (SPF) has been studied. The laboratory scale sheets with an average grain size of 0.3 μm and the commercial size sheets with an average grain size of 0.65 μm were produced by pack rolling manufacturing technique from the forgings with pre-formed submicrocrystalline (SMC) structure. The sheets possessing isotropic mechanical properties in the sheet plane had higher yield strength, ultimate tensile strength. Over the exceptionally low temperature range of 700-750°C the SMC sheets demonstrated enhanced superplastic properties, namely an initial flow stress of 20-25 MPa and elongation more than 600% at the strain rate of 3×10-4/s. The sheet material with SMC structure was characterized by well formability compared to a conventional sheet under low temperature superplastic conditions.

Effect of Annealing on the Microstructure and Mechanical Properties of Mg-9Al% Alloy Plates Processed With Symmetrical and Asymmetrical Rolling

2019 ◽  
Author(s):  
Zhigang Xu ◽  
Honglin Zhang ◽  
Sergey Yarmolenko ◽  
Qiuming Wei ◽  
Laszlo Kecskes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Annealing Temperature ◽  
Static Recrystallization ◽  
Annealing Treatment ◽  
Good Combination ◽  
Basal Texture ◽  
Asymmetrical Rolling ◽  
Microstructure And Mechanical Properties ◽  
Strength And Ductility

Abstract In this study, the Mg-9Al% plates with a total of approximately 50% thickness reduction corresponding to 0.76mm per pass, were obtained by symmetrical and asymmetrical rolling. The effect of different annealing temperature and corresponding holding time on the microstructure and mechanical properties were investigated. Key results showed that in the as-rolled state, the plates processed by asymmetrical rolling had smaller grain size and higher hardness value and ultimate tensile strength than symmetrical rolling. After annealing treatment, the hardness value of the both plates decreased due to the internal stress released. A good combination of strength and ductility were achieved for symmetrical and asymmetrical processed plates at 350°C for 1 hour and 325°C for 1 hour, respectively, which can be attributed to the static recrystallization and weakening the basal texture. These results show that the appropriate annealing is an effective way to enhance the mechanical formability of plastic deformed Mg plates.

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