Anisotropy in tensile behavior of an extruded Mg-4.50Zn-1.13Ca (wt.%) alloy

2021 ◽  
Vol 112 (10) ◽  
pp. 787-793
Author(s):  
Yuzhou Du ◽  
Mingyi Zheng ◽  
Yanfeng Ge ◽  
Bailing Jiang
Keyword(s):  
Tilt Angle ◽  
Basal Slip ◽  
Tensile Deformation ◽  
Extrusion Direction ◽  
Deformation Mode ◽  
Tensile Behavior ◽  
Prismatic Slip ◽  
Basal Texture ◽  
Tensile Direction ◽  
Deformation Modes

Abstract The present study investigated anisotropy in tensile behavior of an extruded Mg-4.50Zn-1.13Ca (wt.%) alloy through tensile testing along different tilt angles relative to the extrusion direction. Results showed that the as-extruded Mg-4.50Zn-1.13Ca (wt.%) alloy exhibited anisotropy in tensile behavior due to the formation of basal texture. Basal slip, prismatic slip and tensile twinning were the dominant deformation modes depending on the tensile direction. Prismatic slip was the dominant deformation mode for samples with small tilt angle (θ = 0° and 22.5°). Basal slip was activated when the tilt angle was increased, which also resulted in the decrease of yield strength. Tensile twinning was responsible for the yielding of the samples with high tilt angles (θ = 67.5° and 90°). The ductility was significantly reduced at high tilt angle, which was mainly attributed to the appearance of tensile twinning during tensile deformation.

Effects of Texture on the Fracture Mechanism of AZ31 Magnesium Alloy under Dynamic Impact

2014 ◽  
Vol 598 ◽  
pp. 98-101
Author(s):  
Gang Wan ◽  
Bao Lin Wu
Keyword(s):  
Magnesium Alloy ◽  
Basal Slip ◽  
Az31 Magnesium Alloy ◽  
Prismatic Slip ◽  
Shearing Stress ◽  
Basal Texture ◽  
Dynamic Impact ◽  
Pyramidal Slip ◽  
Schmid Factor ◽  
Deformation Modes

the hot extruded AZ31 magnesium alloy which has basal texture was impacted along different direction and different fracture mode appeared. Under different impacted direction, the basal slip, prismatic slip, pyramidal slip, compression twin and tension twin have different critical resolved shearing stress (CRSS) and Schmid factor. Then different deformation modes were activated and resulted to different fracture modes.

scholarly journals Effect of Loading Direction on the Tensile Properties and Texture Evolution of AZ31 Magnesium Alloy

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1193
Author(s):  
Yuyu Li ◽  
Tingzhuang Han ◽  
Zhibing Chu ◽  
Chun Xue ◽  
Qianhua Yang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Texture Evolution ◽  
Extrusion Direction ◽  
Deformation Mode ◽  
Tensile Behavior ◽  
Mechanical Anisotropy ◽  
Az31 Magnesium Alloy ◽  
Prismatic Slip ◽  
Uniaxial Tensile ◽  
Loading Direction

Samples were cut from an extruded AZ31 magnesium alloy bar for uniaxial tensile and EBSD characterization tests. The long axis and bar extrusion directions were 0° (T0 sample), 45° (T45 sample), and 90° (T90 sample). The effects of loading direction on the tensile behavior, microstructure, and texture evolution of the magnesium alloy were studied. Results show that the obvious mechanical anisotropy of tensile behavior is affected by the loading direction, and the T0 sample with a grain c-axis perpendicular to the extrusion direction has a strong basal texture and high flow stress and yield strength. The loading direction has a significant influence on the microstructure characteristics of different samples, especially the number of {10–12} tensile twins and {10–11} compression twins. Texture evolution results show that the loading direction and the effect of deformation mode on the deformation mechanism lead to variations in texture evolution: the basal slip and prismatic slip during the plastic deformation of the T0 specimen, the compression twin of the T45 specimen, and the tensile twin of the T90 specimen.

Modelling of the Strain Hardening Behaviour of Die-Cast Magnesium-Aluminium-Rare Earth Alloy

2020 ◽  
Vol 35 ◽  
pp. 1-8
Author(s):  
Hua Qian Ang
Keyword(s):  
Strain Hardening ◽  
Tensile Deformation ◽  
Deformation Behaviour ◽  
Strain Curve ◽  
Deformation Mode ◽  
Prismatic Slip ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Die Cast ◽  
Cast Magnesium

The tensile deformation behaviour of magnesium alloy AE44 (Mg-4Al-4RE) under strain rates ranging from 10-6 to 10-1 s-1 has been investigated. Present study shows that the deformation mode begins with the activation of elastic (Stage 1), followed by <a> basal slip and twinning (Stage 2), <a> prismatic slip (Stage 3) and finally to <c+a> pyramidal slip (Stage 4). The commencement of these deformation mechanisms results in four distinct stages of strain hardening in the stress-strain curve. In this work, the four stages of deformation behaviour are modelled, and an empirical equation is proposed to predict the entire stress-strain curve. Overall, the model predictions are in good agreement with the experimental data. This study on the decomposition of stress-strain curve into four stages provides insights into the contribution of individual deformation mechanism to the overall deformation behaviour and opens a new way to assess mechanical properties of die-cast magnesium alloys.

scholarly journals Reducing Yield Asymmetry between Tension and Compression by Fabricating ZK60/WE43 Bimetal Composites

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 249
Author(s):  
Kangning Zhao ◽  
Dexing Xu ◽  
Xiao Song ◽  
Yingzhong Ma ◽  
Hongxiang Li ◽  
...  
Keyword(s):  
Deformation Mechanism ◽  
Deformation Behavior ◽  
Extrusion Direction ◽  
Stress Transfer ◽  
Prismatic Slip ◽  
Special Method ◽  
Interface Microstructure ◽  
Tension And Compression ◽  
Deformation Modes ◽  
Bimetal Composite

In this study ZK60/WE43 bimetal composite rods were manufactured by a special method of hot diffusion and co-extrusion. Interface microstructure, deformation mechanism, and yield asymmetry between tension and compression for the composite rods were systematically investigated. It was observed that the salient deformation mechanism of the ZK60 constituent was {10-12}<−1011> extension twinning in compression and prismatic slip in tension, and different deformation modes resulted in yield asymmetry between tension and compression. In contrast, the WE43 constituent tends to be more isotropic due to grain refinement, texture weakening, solid-solution and precipitation strengthening, which were deformed via basal slip, prismatic slip, and {10-12}<−1011> extension twinning in both tension and compression. Surprisingly, it was found that yield asymmetry between tension and compression for the ZK60/WE43 composite rods along the extrusion direction was effectively reduced with a compression-to-tension ratio of ~0.9. The strongly bonded interface acting as a stress transfer medium for the ZK60 sleeve and WE43 core exhibited the coordinated deformation behavior. This finding provides an effective method to decrease the yield asymmetry between tension and compression in the extruded magnesium alloys.

Activities of Non-Basal Slips in Deformation of Magnesium Alloy Single and Poly Crystals

2018 ◽  
Vol 941 ◽  
pp. 1242-1247
Author(s):  
Shinji Ando ◽  
Hiroaki Rikihisa ◽  
Masayuki Tsushida ◽  
Hiromoto Kitahara
Keyword(s):  
Magnesium Alloy ◽  
Single Crystals ◽  
Basal Plane ◽  
Basal Slip ◽  
Tensile Deformation ◽  
Deformation Behaviour ◽  
Pure Magnesium ◽  
Prismatic Slip ◽  
Polycrystalline Specimen ◽  
Yttrium Addition

In this study, to investigate effects of yttrium and other elements for non-basal slips, magnesium alloy single crystals were stretched parallel to basal plane in various temperatures, and polycrystalline magnesium alloys were also tested to estimate contribution of non-basal slips to their tensile deformation behaviour. In pure magnesium single crystals, second order pyramidal (c+a) slip (SPCS) was observed at 298K. Above room temperature, first order pyramidal (c+a) slip (FPCS) was active. In the Mg - (0.6-0.9) Y alloy single crystals, FPCS was observed at 77K to 298K, while yield stress of the Mg-Y alloy single crystals was higher than that of pure magnesium. In tensile test of polycrystalline specimen, slips lines of non-basal slip systems such as SPCS, FPCS and prismatic slip were observed even at yielding in addition to basal slip lines. Among the non-basal slips, activities of FPCS and prismatic slips were increased with increasing strain in Mg - Y alloy polycrystals. Our study suggested that active non-basal slip system in tension parallel to basal plane is (c+a) pyramidal slip and enhanced ductility of magnesium - yttrium alloy would be caused from increased activity of FPCS by yttrium addition.

Dislocations in alumina deformed by prismatic slip

1978 ◽  
Vol 36 (1) ◽  
pp. 606-607
Author(s):  
J. Cadoz ◽  
J. Castaing ◽  
J. Philibert
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basal Slip ◽  
Prismatic Slip ◽  
Compression Tests ◽  
Thin Sections ◽  
Burgers Vector ◽  
Maximum Deformation ◽  
Transmission Electron ◽  
Mechanical Thinning

Plastic deformation of alumina has been much studied; basal slip occurs and dislocation structures have been investigated by transmission electron microscopy (T.E.M.) (1). Non basal slip has been observed (2); the prismatic glide system <1010> {1210} has been obtained by compression tests between 1400°C and 1800°C (3). Dislocations with <0110> burgers vector were identified using a 100 kV microscope(4).We describe the dislocation structures after prismatic slip, using high voltage T.E.M. which gives much information.Compression tests were performed at constant strainrate (∿10-4s-1); the maximum deformation reached was 0.03. Thin sections were cut from specimens deformed at 1450°C, either parallel to the glide plane or perpendicular to the glide direction. After mechanical thinning, foils were produced by ion bombardment. Details on experimental techniques can be obtained through reference (3).

Effects of Deformation Mode on Resistivity Curve Used for Estimating Martensite Induced in Stainless Steel

2010 ◽  
Vol 638-642 ◽  
pp. 2992-2997 ◽  
Author(s):  
Hidefumi Date
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Linear Relation ◽  
Volume Fraction ◽  
Tensile Deformation ◽  
Deformation Mode ◽  
Transformation Process ◽  
Martensite Formation ◽  
Austenitic Phase ◽  
Ε Phase

The martensite induced in three types of austenitic stainless steel, which indicate the different stability of the austenitic phase (γ), were estimated by the resistivity measured during the tensile deformation or compressive deformation at the temperatures 77, 187 and 293 K. The resistivity curves were strongly dependent on the deformation mode. The volume fraction of the martensite (α’) was also affected by the deformation mode. The ε phase, which is the precursor of the martensite and is induced from the commencement of the deformation, decreased the resistivity. However, lots of defects generated by the deformation-induced martensite increased the resistivity. The experimental facts and the results shown by the modified parallelepiped model suggested a complicated transformation process depending on each deformation mode. The results shown by the model also suggested a linear relation between the resistivity and the martensite volume at the region of the martensite formation. The fact denoted that the resistivity is mostly not controlled by the austenite, ε phase and martensite, but by the defects induced due to the deformation-induced martensite.

Improvement of Strength of Mg-12Gd-3Y-0.5Zr Alloys Processed by Combination of ECAP and Extrusion

2011 ◽  
Vol 682 ◽  
pp. 211-216
Author(s):  
Rong Zhu ◽  
Jin Qiang Liu ◽  
Jing Tao Wang ◽  
Ping Huang ◽  
Yan Jun Wu ◽  
...  
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Grain Boundary ◽  
Low Temperatures ◽  
Basal Slip ◽  
Extrusion Direction ◽  
Strengthening Mechanisms ◽  
Step Process ◽  
Angular Pressing ◽  
Peak Intensity

Equal channel angular pressing (ECAP) has been used to refine the grain size of Mg-12Gd-3Y-0.5Zr billet at about 400°C because it lacks sufficient ductility at low temperatures. However, <0001> peak intensity is oriented about 50º from the extrusion direction, which facilitates the basal slip, and decreases the yield strength. We have employed conventional extrusion at 300°C following ECAP to modify the texture in hard orientation. This two-step process makes use of two strengthening mechanisms a) grain boundary strengthening due to small grain size, and (b) texture strengthening due to grains in hard orientation. The samples processed by the two-step show the yield and ultimate strength to 283 and 308 MPa, respectively. Moreover, the activation of <c+a> slip and fine grains resulted from the ECAP helped to maintain a good ductility even after significant straining from conventional extrusion.

scholarly journals An Experimental Study of the Tension-Compression Asymmetry of Extruded Ti-6.5Al-2Zr-1Mo-1V under Quasi-Static Conditions at High Temperature

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1299
Author(s):  
Chen Zhang ◽  
Dongsheng Li ◽  
Xiaoqiang Li ◽  
Yong Li
Keyword(s):  
High Temperature ◽  
Strain Hardening ◽  
Yield Stress ◽  
Mechanical Response ◽  
Tensile Deformation ◽  
Uniaxial Tensile ◽  
Tensile Direction ◽  
Stress Asymmetry ◽  
Static Conditions ◽  
Tension Compression Asymmetry

The tension-compression asymmetry (TCA) behavior of an extruded titanium alloy at high temperatures has been investigated experimentally in this study. Uniaxial tensile and compressive tests were conducted from 923 to 1023 K with various strain rates under quasi-static conditions. The corresponding yield stress and asymmetric strain hardening behavior were obtained and analyzed. In addition, the microstructure at different temperatures and stress states indicates that the extruded TA15 profile exhibits a significant yield stress asymmetry at different testing temperatures. The flow stress and yield stress during tension are greater than compression. The yield stress asymmetry decreases with the increase in temperature. The alloy also exhibits TCA behavior on the strain hardening rate. Its mechanical response during compression is more sensitive than tension. A dynamic recrystallization phenomenon is observed instead of twin generated in tension and compression under high-temperature quasi-static conditions. The grains are elongated along the tensile direction and deformed by about 45° along the compressive load axis. Finally, the TCA of Ti-6.5Al-2Zr-1Mo-1V (TA15) alloy is due to slip displacement. The tensile deformation activates basal <a>, prismatic <a> and pyramidal <c + a> slip modes, while the compressive deformation activates only prismatic <a> and pyramidal <c + a> slip modes.

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