Tensile Properties of AZX612 Magnesium Alloy Sheets Processed by Friction-Assisted Extrusion

2018 ◽  
Vol 385 ◽  
pp. 91-96
Author(s):  
Satoshi Kobune ◽  
Goroh Itoh
Keyword(s):  
Tensile Properties ◽  
Elevated Temperatures ◽  
Extrusion Direction ◽  
Initial Strain Rate ◽  
Grain Boundary Sliding ◽  
Rolled Sheet ◽  
Lateral Extrusion ◽  
Boundary Sliding ◽  
Rolled Condition ◽  
Extrusion Method

Tensile properties at room and elevated temperatures of AZX612 alloy sheets processed by a kind of lateral extrusion method namely Friction-Assisted Extrusion (FAE) were investigated. The FAE was developed to control the texture, and carried out at temperatures ranging from 250 to 350°C with an extrusion ratio of 4 from the as-rolled condition. The results showed that FAE changes the basal texture of the as-rolled sheet into that inclined by about 15˚ against the extrusion direction and raises the intensity of the texture. It was observed that the significant microstructure refinement from as-rolled condition of 10.8μm to 4.7μm after FAE due to dynamic recrystallization at the extrusion temperature of 250°C. The 0.2% proof stress of the FAEed sheets at room temperature became significantly smaller than that of the as-rolled sheet in the extrusion direction but became larger in the transverse direction, resulting in the larger anisotropy. This can be understood by the activity of basal slip. The anisotropy of the tensile properties disappeared at a temperature of 300°C and an initial strain rate of 3.3×10-4s-1. In addition, the elongation was improved from 72% of the as-rolled sheet to 152% at maximum of the FAEed sheets in the extrusion direction. This improvement was attributable to superplastic flow based on grain boundary sliding.

Superplasticity of Mg-Zn-Y Alloy Prepared by Extrusion of Machined Chip

2012 ◽  
Vol 735 ◽  
pp. 259-264
Author(s):  
Takaomi Itoi ◽  
Syuichi Fudetani ◽  
Mitsuji Hirohashi
Keyword(s):  
Grain Size ◽  
Hot Extrusion ◽  
Initial Strain Rate ◽  
Grain Boundary Sliding ◽  
Initial Strain ◽  
Strain Rates ◽  
Long Period ◽  
Dominant Deformation Mechanism ◽  
Mean Grain Size ◽  
Boundary Sliding

Mg96Zn2Y2 (at.%) extruded alloy was fabricated by hot-extrusion of the Mg96Zn2Y2 machined chip. The Mg96Zn2Y2 extruded alloy consisted of a long period stacking ordered (LPSO)-, Mg3Zn3Y2- and Mg- phases. The Mg phase with mean grain size of 450 nm was confirmed by TEM. However, the LPSO- and Mg3Zn3Y2- phases had relatively large grain size compared with Mg phase. The Mg96Zn2Y2 extruded alloy also showed superplasticity at temperatures of 623 K and 723 K with initial strain rates from 2×10−1 s−1 to 2×10−3 s−1. The maximum elongation of 450 % was achieved at 723 K with an initial strain rate of 2×10−3 s−1. From TEM observation, it is considered that grain boundary sliding of Mg grains was dominant deformation mechanism of the Mg96Zn2Y2 extruded alloy at high temperature range.

Grain boundary sliding in nanomaterials at elevated temperatures

2006 ◽  
Vol 42 (5) ◽  
pp. 1433-1438 ◽  
Author(s):  
A. V. Sergueeva ◽  
N. A. Mara ◽  
A. K. Mukherjee
Keyword(s):  
Grain Boundary ◽  
Elevated Temperatures ◽  
Grain Boundary Sliding ◽  
Boundary Sliding

Influence of Interstitial Impurities on Deformational Behavior and Fracture Mechanism of Submicrocrystalline Titanium at Room and Elevated Temperatures

2014 ◽  
Vol 1013 ◽  
pp. 138-145 ◽  
Author(s):  
Evgenii Dudarev ◽  
Galina Bakach ◽  
Aleksandr I. Potekaev ◽  
Yurii Kolobov ◽  
Oleg Kashin ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Elevated Temperatures ◽  
Grain Boundary Sliding ◽  
Interstitial Impurity ◽  
Coarse Grained ◽  
Interstitial Impurities ◽  
Localization Of Plastic Deformation ◽  
Deformational Behavior ◽  
Boundary Sliding ◽  
High Degree

General trends and other aspects of the deformational behavior, localization of plastic deformation on the macroscale level, and fracture of submicrocrystalline and coarse-grained titanium with different interstitial impurity levels are established. It is shown that for the submicrocrystalline structure as well as for the coarse-grained structure, strengthening by interstitial impurities decreases with increase of the deformation temperature. Experimental data are presented which indicate that in the development of grain-boundary sliding in submicrocrystalline titanium with simultaneous onset of recrystallization, a high degree of plastic deformation is reached before fracture occurs, where the deformational behavior and localization of plastic deformation on the macroscale level are analogous to the same processes under superplastic flow.

Deformation Behavior of a Multiphase Fine-Grained Mo-Si-B Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 544-549
Author(s):  
J.L. Yu ◽  
Z.K. Li ◽  
Xin Zheng ◽  
H. Li ◽  
D. H. Wang ◽  
...  
Keyword(s):  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Size Range ◽  
Tensile Elongation ◽  
Grain Boundary Sliding ◽  
Intermetallic Phases ◽  
Fine Grained ◽  
Fine Microstructure ◽  
Boundary Sliding ◽  
Hot Pressing Sintering

Mo-9Si-8B-3Hf alloy consisting of a Mo solid solution and intermetallic phases Mo3Si and Mo5SiB2was fabricated by hot pressing sintering to yield a fine microstructure with all three phases being in the size range of micrometer. The tensile properties of this alloy at elevated temperature were evaluated in vacuum at elevated temperatures. This alloy displayed extensive plasticity or superplasticity at temperatures ranging from 1400 °C to 1560 °C with strain rate of 3×10-4s-1. The tensile elongation of 410% is measured at 1560 °C. Grain boundary sliding is the main mechanism of plastic deformation for this alloy.

Evolution of Microstructures and Mechanical Properties of Sr and Ca Containing Mg-4Al Alloy during Annealing Heat Treatment

2011 ◽  
Vol 311-313 ◽  
pp. 772-777
Author(s):  
Jing Bai ◽  
Yang Shan Sun ◽  
Feng Xue
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Elevated Temperatures ◽  
Creep Property ◽  
Grain Boundary Sliding ◽  
Al Alloy ◽  
Creep Properties ◽  
Lamellar Eutectic ◽  
Annealing Heat Treatment ◽  
Boundary Sliding

Microstructures, mechanical and creep properties of as-cast and as-annealed Mg-4Al-2Sr-1Ca (AJX421) alloy were investigated. The as cast microstructures of the alloy consists of the α-Mg, lamellar eutectic Mg2Ca and bulky Mg-Al-Sr phase. After annealing at 400°C, lamellar eutectic tended to be spheroidised and the continuous interphase network breaks up gradually, meanwhile, C14-Mg2Ca completely transforms to C15-Al2Ca. These results in obvious decrease of creep property. It is proposed that the continuous network distribution of compounds paly a major role in restricting the creep deformation of Mg-Al alloy at elevated temperatures, and the grain boundary sliding is an important creep mechanism for the alloy studied.

The Development of Superplasticity and Deformation Mechanism Maps in an Ultrafine-Grained Magnesium Alloy

2016 ◽  
Vol 879 ◽  
pp. 48-53
Author(s):  
Megumi Kawasaki ◽  
Roberto B. Figueiredo ◽  
Terence G. Langdon
Keyword(s):  
Deformation Mechanism ◽  
Elevated Temperatures ◽  
Grain Boundary Sliding ◽  
Grain Structure ◽  
Superplastic Behavior ◽  
Ultrafine Grained ◽  
Controlling Mechanism ◽  
Zk60 Alloy ◽  
Boundary Sliding ◽  
Coble Creep

Magnesium alloys with refined grain structure are often superplastic at elevated temperatures with maximum elongations up to more than 1000%. The superplastic behavior of this material agrees with deformation by grain boundary sliding. Dislocation climb becomes the rate controlling mechanism at higher stresses but the rate controlling mechanism at lower stresses is not fully documented. This report examines the development of superplasticity in a magnesium ZK60 alloy and shows that an increase in stress exponent and decrease in elongation takes place at low stresses. Deformation mechanism maps are constructed considering Regions I, II and III and Coble creep.

Tensile Properties of Hot Extruded Mg-Zn-Nd-Y-Zr Alloy at Elevated Temperatures

2011 ◽  
Vol 415-417 ◽  
pp. 1157-1163
Author(s):  
Xiao Zhou ◽  
Hai Tao Zhou ◽  
Zhen Dong Zhang ◽  
Rui Rui Liu ◽  
Li Bin Liu
Keyword(s):  
Strain Rate ◽  
Elevated Temperatures ◽  
Peak Stress ◽  
Tensile Tests ◽  
Grain Boundary Sliding ◽  
Strain Rates ◽  
Zk60 Alloy ◽  
Boundary Sliding ◽  
Increasing Temperature ◽  
Zr Alloy

Mechanical properties of extruded Mg-Zn-Nd-Y-Zr alloy are investigated by tensile tests at various temperatures range from room temperature to 350°C with strain rates of 6.0×10-4-6.0×10-1s-1. It is found that the peak decrease with increasing temperature and decreasing strain rate, while the elongation increases with increasing temperature and decreasing strain rate. When deformation temperature is over 250°C, superplasticity occurs. This is ascribed to grain boundary sliding accommodated cavities growth. . At low temperature, the peak stress are a relatively higher than that of ZK60 alloy. This is explained by the grain refining effect and the precipitates of Mg9Nd and Mg6Zn3Y2.

Indentation Contact Deformation of 3Y-TZP at Elevated Temperatures

2006 ◽  
Vol 317-318 ◽  
pp. 469-472
Author(s):  
Hiroyuki Muto ◽  
R. Yamada ◽  
Atsunori Matsuda ◽  
Mototsugu Sakai
Keyword(s):  
Elevated Temperatures ◽  
Penetration Rate ◽  
Contact Region ◽  
Tetragonal Zirconia ◽  
Grain Boundary Sliding ◽  
Indentation Creep ◽  
Contact Deformation ◽  
Creep Tests ◽  
Creep Time ◽  
Boundary Sliding

The contact deformation mechanisms of a superplastic ceramic, 3Y-TZP (3mol % yttria-partially stabilized tetragonal zirconia polycrystals) are examined in indentation creep tests at high temperatures. A large discrepancy between the uniaxial compression and the pyramidal indentation contact behaviors is observed. The indentation creep curves exhibit a hardening behavior, i.e., the penetration rate decreases as the penetration depth and/or the creep time increases. This fact implied that the cooperative grain-boundary sliding (CGBS) in a microscopically localized region, such as the sub-surface contact region beneath a pyramidal indenter, is very limited through the microscopic processes of localized grain interlocking.

Microstructure and Mechanical Properties of Electrodeposited Nickel and its Particle-Reinforced Nanocomposite

2007 ◽  
Vol 567-568 ◽  
pp. 205-208 ◽  
Author(s):  
Petra Cihlářová ◽  
Jiří Švejcar ◽  
Vàclav Sklenička
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Elevated Temperatures ◽  
Creep Behaviour ◽  
Grain Boundary Sliding ◽  
Pure Nickel ◽  
Dislocation Creep ◽  
Nano Composite ◽  
Electrodeposited Nickel ◽  
Boundary Sliding

There are two types of experimental material used – pure nickel and its nano-composite reinforced with nano-sized SiO2. These materials were produced by TU Clausthal, Germany. The results have shown that the creep resistance of the nickel nano-composite reinforced with nanosized SiO2 particles is higher in comparison with non-reinforced nickel. The mechanism responsible for creep behaviour is the dislocation creep at 293 K and at elevated temperatures the dislocation creep is controlled by grain boundary sliding.

Anisotropic Tensile Properties at Room and Elevated Temperatures in Warm-Extruded AZ61 Magnesium Alloy

2005 ◽  
Vol 495-497 ◽  
pp. 657-662 ◽  
Author(s):  
Yi Nong Wang ◽  
J.C. Huang
Keyword(s):  
Tensile Properties ◽  
Elevated Temperatures ◽  
Extrusion Direction ◽  
Mechanical Anisotropy ◽  
Lower Yield ◽  
Texture Characteristics ◽  
Lower Yield Strength ◽  
Schmid Factor ◽  
The Relationship ◽  
Loading Axis

The texture characteristics and the relationship between texture and tensile properties at room temperature and superplasticity at high temperatures in a hot extruded AZ61 alloy are examined in this paper. After warm extrusion, the alloy exhibits a of refined grains microstructure and a sharp basal {0001} texture. The tensile properties at room and elevated temperatures in extruded with the loading axis oriented at 0°, 45° and 90° to the extrusion direction are tested. It is found that the 45° specimens exhibit has lower yield strength and higher ductility. The possible causes for mechanical anisotropy are also analyzed based on the Schmid factor calculations.

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