The Microstructures and Mechanical Properties of Hot-Processed Magnesium Casting Alloys

2006 ◽  
Vol 503-504 ◽  
pp. 775-780 ◽  
Author(s):  
Takeshi Yamaguchi ◽  
Tadayoshi Tsukeda ◽  
Ken Saito ◽  
Yoshihito Kawamura
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Extrusion Direction ◽  
High Strength ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Tensile Yield Strength ◽  
Extrusion Force ◽  
Casting Alloys ◽  
Magnesium Casting

In order to make the effect of processing clear, AM50A magnesium casting alloys were extruded at various extrusion conditions such as extrusion temperature and extrusion ratio. The mechanical properties of AM50A alloy increased with decreasing extrusion temperature. Tensile yield strength and tensile strength of extruded AM50A alloy were 389MPa and 420MPa respectively when the extrusion temperature was 348K. The microstructure of the extruded magnesium alloy showed large grains stretched to the extrusion direction and fine recrystallized grains. Decreased extrusion temperature resulted in improved strength and decreased elongation with increasing of the degree of work hardens and extrusion force. When the extrusion ratio is high, improvement of strength is prevented by rycrystallization and it was observed as crystal orientation by XRD. The elongation of the extrusion increased with the recrystallization of grains. Every magnesium alloy extruded at low temperature has high strength.

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 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.

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.

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.

Improving the Mechanical Properties of AZ31 Mg Alloy by High Ratio Extrusion

2006 ◽  
Vol 503-504 ◽  
pp. 865-870 ◽  
Author(s):  
Yongjun Chen ◽  
Qu Dong Wang ◽  
Jianguo Peng ◽  
Chun Quan Zhai
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
High Ratio ◽  
Extrusion Ratio ◽  
Mg Alloy ◽  
Fine Grained ◽  
Az31 Mg Alloy ◽  
Industry Applications ◽  
One Step ◽  
The One

Experiments were conducted both to evaluate the potential for grain refinement, the subsequent mechanical properties at room temperature in samples of AZ31 Mg alloy and also to investigate the relationship between one-step and two-step high ratio extrusion (HRE). The one-step HRE was undertaken using a high extrusion ratio of 70:1 at 250, 300 and 350°C. And the two-step HRE was conducted with an extrusion ratio of 7 for the first step at 250, 300 and 350°C, followed by a second-step extrusion with an extrusion ratio of 10 at 250, 300 and 350°C. The initial grain size in the AZ31 ingot was 100μm and that after one-step HRE became similar to 5μm, after two-step HRE at 250, 300 and 350°C were 2, 4, 7μm, respectively, resulting in superior mechanical properties at ambient temperature. The microstructure of two-step HRE was finer and uniformer than that of one-step HRE and the strength of one-step and two-step HRE were similar, moreover, the elongation of one-step HRE was improved markedly than that of two-step HRE. Dynamic recrystallization and adjacent grain broking during HRE is introduced to explain the effects of one-step and two-step HRE on the microstructure and mechanical properties of AZ31 Mg alloy. The current results imply that the simple HRE method might be a feasible processing method for industry applications, and the multiply steps extrusion are effective to fabricate high strength of fine grained hcp metals.

Study on Aging Strengthening Behavior of ZK60 -2.0%Nd-1.0%Y Alloy

2010 ◽  
Vol 34-35 ◽  
pp. 1651-1655
Author(s):  
An Ru Wu ◽  
Li Jun Dong ◽  
Wei Guo Gao ◽  
Xiang Ling Zhou
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Rare Earth ◽  
Magnesium Alloy ◽  
Rare Earth Elements ◽  
Aging Process ◽  
Equilibrium Phase ◽  
High Strength ◽  
Treatment Method ◽  
Zk60 Alloy

The microstructure and mechanical properties of Mg-6.0%Zn-0.5%Zr (ZK60) and ZK60-2.0%Nd-1.0%Y alloys after extrusion, rolling and then T5 and T6 heat-treatment were investigated. The hardness and tensile strength at T5 and T6 condition were tested. The results show that the mechanical properties of ZK60--2.0%Nd-1.0%Y alloy are superior to that of ZK60 alloy. The hardness of the investigated alloy at T5 condition is higher than at T6. The strengthening of ZK60-2.0%Nd-1.0%Y alloy originates from the interaction of phase and dislocations. The precipitation order of ZK60-2.0%Nd-1.0%Y alloy is GP zone . The magnesium alloy contains rare earth elements with good casting performance, great potential for plastic deformation, high strength, excellent mechanical properties and many other advantages. The magnesium alloy oversaturation solid solution's decomposition process conforms to time the common alloy oversaturation solid solution decomposition order rule, often namely before separating out the equilibrium phase presents some transitional stage the structure, like the GP area, the transition are equal, but the different series magnesium alloy presents the different characteristic, therefore uses the heat treatment method also has big difference [1-5]. In this paper, we will analysis mechanical properties of aging process of testing and microstructure of Mg-6.0% Zn-0.5% Zr-2.0% Nd-1.0% Y alloy , do Research about strengthen the effect of melting and from the product of the relationship on different alloy aging process, and analysis contribution of rare earth elements Nd, Y to alloy strengthen.

Fracture Analysis and Mechanical Property of AZ91D Magnesium Alloy Chips Prepared by Solid State Recycling

2006 ◽  
Vol 324-325 ◽  
pp. 499-502
Author(s):  
Ze Sheng Ji ◽  
Mao Liang Hu ◽  
Xiao Yu Chen
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Magnesium Alloy ◽  
Hot Extrusion ◽  
Casting Process ◽  
Fracture Analysis ◽  
Extrusion Ratio ◽  
Cold Press ◽  
Az91d Magnesium Alloy ◽  
Chips Recycling

AZ91D magnesium alloy is prepared by hot extrusion of recycled machined chips and its fractures and mechanical properties are investigated at various extrusion conditions. Cold-press is employed to prepare extrusion billets of AZ91D magnesium alloy chips, and then the billets are hot extruded at 573K-723K with an extrusion ratio of 11:1. The results show that tensile strength and elongation of the extrusion magnesium alloy with the extrusion temperature of 673K and the extrusion rate of 0.08mm/s can reach 380MPa and 6%, respectively. Fracture surface presents a mix mechanism of dimple-like fracture and gliding fracture. Due to grain refinement by cold-press and hot extrusion, mechanical properties of extruded rods are much higher than those of as-cast AZ91D magnesium alloy. Also, much lower energy consumption is necessary for this recycling compared to the conventional casting process. Solid state recycling is an efficient method for magnesium alloy chips recycling.

scholarly journals Effect of Extrusion Ratio & Extrusion Temperature on Mechanical Properties of Hot Extruded Hybrid Composites of Al6061/Sic/Graphite

2019 ◽  
Vol 8 (11) ◽  
pp. 2821-2825
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composites ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Fixed Amount

In this work hot extrusion of hybrid composites of Al6061/SiC/Gr was carried out at ratios of 2:1,3:1&4:1 & temperatures of 4500 ,5000 ,&5500 c at various compositions of 0,2,4,6 &8 % of SiC and fixed amount of graphite i.e 2% using 200 tonn capacity press at a speed of 1mm/sec to investigate mechanical properties like tensile, compression & BHN and after solutionising and aging .It was found that at ratio 3:1 and temperature 5000 c all the above three properties were found to be improved compared to extrusion .

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