Effect of Plastic Deformation on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

2010 ◽  
Vol 139-141 ◽  
pp. 180-184
Author(s):  
Yong Xue ◽  
Zhi Min Zhang ◽  
Li Hui Lang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundaries ◽  
Gradual Increase ◽  
Tensile Tests ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Second Phase ◽  
Strength And Plasticity ◽  
Az80 Alloy

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75) and extrusion temperatures (300°C, 330°C, 360°C, 390°C, 420°C) on the mechanical properties and microstructure of homogenized AZ80 alloy have been investigated through the tensile tests and via metallographic microscope observation. The results show that the alloy’s grain is small and small amounts of black hard and brittle second-phase β (Mg17Al12) are precipitated uniformly along the grain boundary causing the gradual increase of the alloy’s tensile strength at 330°C. When the extrusion temperature is up to 390°C, the grain size increases significantly, but the second phase precipitation along grain boundaries transforms into continuous and uniform-distribution precipitation within the grain. In this case, when the extrusion ratio is 60, the alloy’s tensile strength reaches its peak 390Mpa. As the extrusion temperature increases, inhomogeneous precipitation of the second-phase along grain boundaries increases, causing the decrease of the alloy’s strength. At the same temperature, the tensile strength increases firstly and then decreases as extrusion ratio increases. With the gradual increase of the refinement grain, the dispersed precipitates increase and the alloy’s tensile strength and plasticity reach their peaks when the extrusion temperature is 390°C. As the grain grows, the second phase becomes inhomogeneous distribution, and the alloy’s strength and plasticity gradually decrease.

Influence of Plastic Deformation on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 1082-1086
Author(s):  
Yao Jin Wu ◽  
Zhi Ming Zhang ◽  
Bao Cheng Li ◽  
Bao Hong Zhang ◽  
Jian Min Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Grain Boundaries ◽  
Gradual Increase ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Second Phase ◽  
Az80 Magnesium Alloy ◽  
Strength And Plasticity

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75) and extrusion temperature (300°C, 330°C, 360°C, 390°C, 420°C) on the mechanical properties and microstructure changes of AZ80 magnesium alloy have been investigated through tensile test and via ZEISS digital metallographic microscope observation. Research indicates that the alloy’s plasticity gradually decreases as the temperature increases, and that the alloy’s tensile strength varies with the extrusion ratio. At 330°C, the alloy’s particle grain is small and a small amount of black hard and brittle second-phase β (Mg17Al12) are precipitated uniformly along the grain boundary causing the gradual increase of the alloy’s tensile strength. When the extrusion temperature is up to 390°C, the grain size increases significantly, but the second phase precipitation along grain boundaries transforms into continuous and uniform-distribution precipitation within the grain. In this case, when the extrusion ratio is 60, the alloy’s tensile strength reaches its peak 390 Mpa. As the extrusion temperature increases, inhomogeneous precipitation of the second-phase along grain boundaries increases, causing the decrease of the alloy’s strength. At the same temperature, both the tensile strength and plasticity increases firstly and then decreases as extrusion ratio increases. With the gradual increase of the refinement grain, the dispersed precipitates increase and the alloy’s tensile strength and plasticity reach their peaks when the extrusion temperature is 390°C. As the grain grows, the second phase becomes inhomogeneous distribution, and the alloy’s strength and plasticity gradually decrease.

Influence of Forward Extrusion on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

2011 ◽  
Vol 686 ◽  
pp. 361-366
Author(s):  
Yong Li ◽  
Zhi Min Zhang ◽  
Yong Xue ◽  
Li Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Phase Distribution ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Second Phase ◽  
Forward Extrusion ◽  
Az80 Magnesium Alloy ◽  
Strength And Plasticity

The forward extrusion experiments of homogenized AZ80 magnesium alloy were conducted in the extrusion temperature range of 300°C to 420°C and extrusion ratios between 15 and 75 to study the effect of plastic deformation on the mechanical properties and microstructure. The microstructure and mechanical properties of extrudate were measured by tensile tests and optical microscopy. The results demonstrated that the alloy grains were small, and small amounts of black hard and brittle second-phase precipitated at 330°C. When the extrusion temperature was up to 390°C, the grain size increased significantly, but the second phase precipitation became continuous. And then, in the case of the extrusion ratio of 60, the tensile strength of the alloy reached the peak value of 390 MPa. Inhomogeneous precipitation of the second-phase increased with the increasing of extrusion temperature. At the same temperature, the tensile strength increased firstly and then decreased with increasing extrusion ratio. With the gradual increase of the grain refinement, the dispersed precipitates increased and the tensile strength and plasticity reached their peaks when the extrusion temperature was 390°C. As the grain grew, the second phase distribution became inhomogeneous, and the strength and plasticity gradually decreased.

scholarly journals On the variability in static and cyclic mechanical properties of extruded 7075-T6 aluminum alloy

2021 ◽  
Author(s):  
Matteo Benedetti ◽  
Cinzia Menapace ◽  
Vigilio Fontanari ◽  
Ciro Santus
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fatigue Strength ◽  
High Cycle Fatigue ◽  
Tensile Tests ◽  
Total Elongation ◽  
Extrusion Ratio ◽  
Cycle Fatigue ◽  
Hardness Tests ◽  
Fatigue Endurance

The present paper investigates the variability in the static and cyclic properties of two nominally identical supplies of the aeronautical Al grade 7075-T6. Samples were extracted from extruded bars of 15 mm and 60 mm diameter and with slightly different chemical composition. Noticeable differences were found in tensile strength, total elongation, low- and high-cycle fatigue strength, despite the nearly identical hardness value. The diverse mechanical behavior has been imputed to different extrusion ratio and therefore work hardening along with a more or less fine distribution of precipitates and dispersoids. The high-cycle fatigue strength was found to be in direct correlation with the monotonic yield strength and the size of the largest intermetallic precipitate. A simple equation based on Murakami sqrt(area) parameter is proposed to predict the fatigue endurance. Tensile tests and microstructural analyses are recommended instead of conventional hardness tests to have a tighter quality control on the mechanical properties of semifinished products.

Effect of Forward Extrusion and Heat Treatment on Microstructure and Mechanical Properties of as-Cast ZK60 Magnesium Alloy

2010 ◽  
Vol 148-149 ◽  
pp. 332-337 ◽  
Author(s):  
Yong Xue ◽  
Zhi Min Zhang ◽  
Li Hui Lang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Tensile Tests ◽  
Extrusion Process ◽  
Extrusion Ratio ◽  
Forward Extrusion ◽  
Zk60 Alloy ◽  
Zk60 Magnesium Alloy

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75), extrusion temperatures (300 , 340 , 380 , 420 , and 460 ), and subsequent heat treatment on the mechanical properties and microstructure of as-cast ZK60 magnesium alloy have been investigated through the tensile tests and via metallographic observation. The results show that forward extrusion process can refine the microstructure of as-cast ZK60 alloy effectively. If as-cast ZK60 alloys have been extruded with the extrusion ratio 45 at 380 ,420 and 460 , respectively, and then post-heat treatment was conducted, the ZK60 alloy’s strength is higher under T5 than T6 treatment. For as-cast ZK60 alloy processed by extrusion and T5 method, the most appropriate temperature for extrusion processing is 300 , at which its tensile strength are highest provided the extrusion ratio is 30 but yet its plasticity is best provided the extrusion ratio is 45. If forward extrusions were conducted at 380 , mechanical properties of ZK60 alloy have little difference as the extrusion ratio varies. When T6 treatment was conducted for the extruded bars, their mechanical properties were improved little, moreover, the bigger the extrusion ratio is, the higher the tensile strength and elongation of the extruded bars become.

scholarly journals Microstructure and Mechanical Behavior of Mg-0.5Si-xSn Alloys

2017 ◽  
Vol 17 (4) ◽  
pp. 179-184
Author(s):  
Xuesong Fu ◽  
Yan Yang ◽  
QuanYang Ma ◽  
Xiaodong Peng ◽  
Tiancai Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elevated Temperature ◽  
Ultimate Tensile Strength ◽  
Temperature Stability ◽  
Tensile Tests ◽  
Extrusion Ratio ◽  
Temperature Performance ◽  
Elevated Temperature Performance ◽  
Si Content

AbstractMg-0.5Si-xSn (x=0.95, 2.9, 5.02wt.%) alloys were cast and extruded at 593K (320oC) with an extrusion ratio of 25. The microstructure and mechanical properties of as-cast and extruded test alloys were investigated by OM, SEM, XRD and tensile tests. The experimental results indicate that the microstructure of the Mg-0.5Si-xSn alloys consists of primary α-Mg dendrites and an interdendritic eutectic containing α-Mg, Mg2Si and Mg2Sn. There is no coarse primary Mg2Si phase in the test alloys due to low Si content. With the increase in the Sn content, the Mg2Si phase was refined. The shape of Mg2Si phase was changed from branch to short bar, and the size of them were reduced. The ultimate tensile strength and yield strength of Mg-0.52Si-2.9Sn alloy at the temperature of 473K (200oC) reach 133MPa and 112MPa respectively. Refined eutectic Mg2Si phase and dispersed Mg2Sn phase with good elevated temperature stability are beneficial to improve the elevated temperature performance of the alloys. However, with the excess addition of Sn, large block-like Mg2Sn appears around the grain boundary leading to lower mechanical properties.

Influence of Hot Extrusion on Microstructure and Mechanical Properties of As-Cast AZ91 Magnesium Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 892-896
Author(s):  
Bao Hong Zhang ◽  
Zhi Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Yield Strength ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Az91 Magnesium Alloy ◽  
Microstructure And Mechanical Properties ◽  
Az91 Magnesium

In order to study the effect of plastic deformation on microstructure and mechanical properties of as-cast AZ91 magnesium alloy, experiments of hot direct extrusion were performed at different extrusion temperatures and different extrusion ratios. The microstructure and mechanical properties of extruded billets and extrudate were measured. Experimental results show that the grain size of as-cast AZ91 magnesium alloy can be dramatically refined by extrusion. Hot extrusion can obviously improve the mechanical properties of as-cast AZ91 magnesium Alloy, comparing with the pre-extruded billet, the tensile strength, yield strength and elongation of extrudate can be improved by at least 69%, 117% and 150% respectively. As the extrusion temperature increases, the tensile strength and yield strength of extrudate will increase. As the extrusion ratio increases, the tensile strength and yield strength of extrudate will increase at first and then fall. At the time of extrusion temperature of 420°C and extrusion ratio of 45, the highest tensile strength of 381Mpa and yield strength of 303MPa can be achieved for the extrudate.

The Mechanical Properties of the Mo-0.5Ti and Mo-0.1Zr Alloys at Room Temperature and High Temperature Annealing

2017 ◽  
Vol 36 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Chaopeng Cui ◽  
Yimin Gao ◽  
Shizhong Wei ◽  
Guoshang Zhang ◽  
Yucheng Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Alloy Element ◽  
Second Phase ◽  
High Temperature Annealing ◽  
Molybdenum Alloys ◽  
Second Phase Particles ◽  
Strength And Plasticity

AbstractMo-0.5Ti and Mo-0.1Zr alloys were prepared by powder metallurgy. In Mo-0.5Ti and Mo-0.1Zr alloys, there appears the second-phase particles of Ti2O3 and ZrO2 respectively, each of which can effectively prevent the dislocation activity in the process of plastic deformation. The addition of Zr can increase the strength of molybdenum alloys. Meanwhile, the ZrO2 formed from the alloy element Zr can refine the grains of molybdenum alloys to improve the recrystallization plasticity. After annealing, the tensile strength decreases while the plasticity greatly increases compared to the annealed Mo-0.5Ti and Mo-0.1Zr alloys. With the increase of annealing temperature, both the tensile strength and plasticity of Mo-0.5Ti and Mo-0.1Zr alloys decrease. Compared with pure Mo, after annealing the properties of the Mo-0.5Ti alloy and the plasticity of the Mo-0.1Zr alloy significantly increases.

Mechanical Properties and Microstructures of Al-12Zn-2.4Mg-1.2Cu Alloy Extruded Sheet

2014 ◽  
Vol 893 ◽  
pp. 402-405
Author(s):  
Gang Chen ◽  
Zhi Min Zhang ◽  
Wei Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Yield Strength ◽  
Scanning Electron Microscope ◽  
Optical Microscopy ◽  
Tensile Tests ◽  
Extrusion Temperature ◽  
Two Stage ◽  
Scanning Electron

Mechanical properties of Al-12Zn-2.4Mg-1.2Cu alloy extruded sheet were investigated by tensile tests. Microstructures were investigated by optical microscopy (OM) and scanning electron microscope (SEM). The result shows that no matter in the L direction or in the T direction, the tensile strength and yield strength decrease with the increasing of the extrusion temperature in different states. The tensile strength and yield strength in the L direction are higher than in the T direction at different extrusion temperatures and different treatment states. When temperature is 340°C, the highest tensile strength is 780 MPa and the highest yield strength is 753 MPa in the two-stage solution and two-stage aging state. The reason for the higher mechanical properties are in the L direction in different states is mainly depend on the distribution direction of the grains.

Mechanical properties of AZ31 Mg alloy recycled by severe deformation

2006 ◽  
Vol 21 (3) ◽  
pp. 754-760 ◽  
Author(s):  
Yasumasa Chino ◽  
Tetsuji Hoshika ◽  
Jae-Seol Lee ◽  
Mamoru Mabuchi
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Yield Stress ◽  
Tensile Tests ◽  
Extrusion Ratio ◽  
Az31 Mg Alloy ◽  
Reference Specimens ◽  
High Extrusion Ratio

AZ31 Mg machined chips were recycled by extrusion at 673 K with a low extrusion ratio of 45:1 and a high extrusion ratio of 1600:1. Oxide contaminants were dispersed more uniformly in the recycled specimen with the high extrusion ratio than in that with the low extrusion ratio. In tensile tests, the recycled specimens with the high extrusion ratio showed about 50% higher 0.2% yield stress and about 20% higher tensile strength compared with those of the reference specimens, which were the extruded AZ31 Mg blocks under the same conditions as the recycled specimens. The improvement of the tensile properties was attributed not only to the small grain size, but also to the dispersed oxide contaminants.

Mechanical Properties of Nano-Scale Mechanically-Milled NiAl

1994 ◽  
Vol 362 ◽  
Author(s):  
Timothy R. Smith
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundaries ◽  
Tensile Tests ◽  
Bend Test ◽  
Theoretical Density ◽  
Nano Scale ◽  
Refined Microstructure

AbstractThis work reports on the mechanical properties of nanocrystalline NiAI materials. Mechanically- milled NiAl with and without Al2O3 additions was forged to 94% of the theoretical density of stoicheometric NiAl at < 0.5 Tm in air. Mechanical properties were investigated by microhardness measurements and the Miniaturized Disk-Bend Test (MDBT). Analysis of the hardness data indicates that most of the compression strengthening is due to the refined microstructure. MDBT results are consistent with tensile tests indicating that the tensile strength is controlled by the strength of grain boundaries.

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