scholarly journals Mechanical Properties and Microstructure Evolution of Mg-6 wt % Zn Alloy during Equal-Channel Angular Pressing

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 841 ◽  
Author(s):  
Jingli Yan ◽  
Zijun Qin ◽  
Kai Yan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Testing Machine ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Zn Alloy

Equal-channel angular pressing (ECAP) was performed on a Mg (6 wt %) Zn alloy at temperatures from 160 to 240 °C and the microstructures and mechanical properties were studied using optical microscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and an electronic universal testing machine. The results showed that ECAP was effective for grain refinement and a bi-modal grain structure formed at low temperatures, which was stable during ECAP from 160 to 200 °C. MgZn2 phase and Mg4Zn7 phase were generated during the ECAP process. The mechanical properties remarkably increased after two repetitions of ECAP. However, the strengths could not be further improved by increasing the plastic deformation, but decreased when ECAP was performed between 200 and 240 °C. The mechanical properties of the ECAP Mg-6Zn alloy was determined by a combination of grain refinement strengthening, precipitation hardening, and texture softening.

Influence of number of ECAP passes on microstructure and mechanical properties of AZ31 magnesium alloy

2012 ◽  
Vol 57 (3) ◽  
pp. 711-717 ◽  
Author(s):  
K. Bryła ◽  
J. Dutkiewicz ◽  
L. Litynska-Dobrzynska ◽  
L.L. Rokhlin ◽  
P. Kurtyka
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Vickers Microhardness ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron

The aim of this work was to investigate the influence of the number of equal channel angular pressing (ECAP) passes on the microstructure and mechanical properties of AZ31 magnesium alloy. The microstructure after two and four passes of ECAP at 423 and 523 K was investigated by means of optical and transmission electron microscopy. The mechanical properties were carried out using Vickers microhardness measurements and compression test. The grain refinement in AZ31 alloy was obtained using ECAP routes down to 1,5 μm at 423 K. Processes of dynamic recrystallization during ECAP were observed. It was found that a gradual decrease of grain size occurs with the increasing of number of ECAP passes. The grain refinement increases mechanical properties at ambient temperature, such as Vickers microhardness and compression strength proportionally to d-0.5.

Investigation on Three-Dimensional Microstructures and Tensile Properties of Pure Iron during Equal-Channel Angular Pressing

2010 ◽  
Vol 667-669 ◽  
pp. 791-796
Author(s):  
Gang Yang ◽  
Mu Xin Yang ◽  
Zheng Dong Liu ◽  
Chang Wang ◽  
Chong Xiang Huang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Band Structure ◽  
Equal Channel Angular Pressing ◽  
Pure Iron ◽  
Three Dimensional ◽  
Microstructural Refinement ◽  
Angular Pressing ◽  
Transmission Electron

Commercial pure iron billets having diameter of 60 mm and length of 180 mm were subjected to equal channel angular pressing (ECAP) at 350 °C for 1-4 passes via route BC. Microstructural evolutions on three planes (X, Y, Z planes) were characterized by optical microscopy and transmission electron microscopy (TEM). It was found that after four passes an ultrafine microstructure could be formed on the X plane, but a band structure remained on the Z plane. Accordingly, the mechanical properties exhibited apparent dependence on the orientations. The strength in the X and Y directions was higher than that in the Z direction. The microstructural refinement and mechanical properties were discussed in terms of experimental results.

Grain Refinement of Pure Copper by ECAP

2008 ◽  
Vol 584-586 ◽  
pp. 393-398 ◽  
Author(s):  
Nayar Lugo ◽  
Jose María Cabrera ◽  
Núria Llorca-Isern ◽  
C.J. Luis-Pérez ◽  
Rodrigo Luri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Grain Refinement ◽  
Strain Distribution ◽  
Room Temperature ◽  
Pure Copper ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Homogeneous Strain

Pure commercial Cu of 99,98 wt % purity was processed at room temperature by Equal- Channel Angular Pressing (ECAP) following route Bc. Heavy deformation was introduced in the samples after a considerable number of ECAP passes, namely 1, 4, 8, 12 and 16. A significant grain refinement was observed by transmission electron microscopy (TEM). Tensile and microhardness tests were also carried out on the deformed material in order to correlate microstructure and mechanical properties. Microhardness measurements displayed a quite homogeneous strain distribution. The most significative microstructural and mechanical changes were introduced in the first ECAP pass although a gradual increment in strength and a slight further grain refinement was noticed in the consecutive ECAP passes.

Equal Channel Angular Pressing of Al Alloy AA2219

2009 ◽  
Vol 67 ◽  
pp. 53-58
Author(s):  
V. Anil Kumar ◽  
M.K. Karthikeyan ◽  
Rohit Kumar Gupta ◽  
P. Ramkumar ◽  
P.P. Sinha
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
High Strength ◽  
Dark Field ◽  
Grain Structure ◽  
Al Alloy ◽  
Angular Pressing

Severe plastic deformation processes (SPD) are gaining importance as advanced materials processing techniques and hold immense potential in obtaining ultra fine-grained high strength materials. Among the SPD techniques, Equal channel angular pressing (ECAP) has its own merits to produce materials with ultra fine grains in bulk with better mechanical properties. The material deforms with high level of plastic strain inside the channel resulting in grain refinement of the output material with improvement in mechanical properties. A very viable die configuration was conceptualized and die was made with 1200 channel angle. Processing of 25 mm dia. of Al alloy AA2219 at room temperature was successfully carried out and grain refinement was observed. The mechanism of grain refinement has been studied using optical and transmission electron microscopy (TEM). It was observed that low energy dislocation structure (LEDS) forms concurrently with sub-grain structure due to dislocation rearrangements, which provide stability to the evolving sub-grain structure. Dislocation mobility is hindered by the presence of precipitates and / or intermetallic dispersoids present in the matrix and results in presence of dislocations in grain interiors. The pile up of dislocations at intermetallic dispersoids was confirmed from the dark field TEM micrographs. Present paper describes the experimental procedure and followed to attain severe plastic deformation through ECAP. Increase in hardness as well as refinement in the grain size after 5-passes have been discussed in light of extensive optical and TEM. The mechanisms of grain refinement to achieve nano-grained structure and strengthening accrued from the grain refinement through ECAP has been discussed.

Annealing Effects in Nanograined Al-Cu-Mg Alloy Processed by Equal Channel Angular Pressing

2017 ◽  
Vol 748 ◽  
pp. 240-244
Author(s):  
Hassan Houcin Ktari ◽  
Jean Philippe Couzine ◽  
Julie Bourgon ◽  
Yannick Champion ◽  
Nabil Njah
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Activation Energy ◽  
Equal Channel Angular Pressing ◽  
Mg Alloy ◽  
Scanning Calorimetry ◽  
Angular Pressing ◽  
Secondary Precipitation ◽  
Transmission Electron ◽  
Annealing Effects

The microstructure and mechanical properties were investigated in an industrial Al-Cu-Mg alloy processed by Equal Channel Angular Pressing ECAP and heating. The die used is formed by two channels intersecting at an angle 90°. Transmission Electron Microscopy (TEM) and orientation (ASTAR) imaging were used in addition to hardness measurements. After heating, a sub-micron grain size is retained. In addition, a further hardening is observed due to secondary precipitation. Differential Scanning Calorimetry (DSC) showed that the activation energy of θ’ precipitation is strongly lowered after ECAP.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

Mechanical Properties and Texture Evolution of AZ31 Mg Alloy during Equal Channel Angular Pressing

2005 ◽  
Vol 475-479 ◽  
pp. 545-548 ◽  
Author(s):  
Hyo Tae Jeong ◽  
Woo Jin Kim
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Texture Evolution ◽  
Fiber Texture ◽  
Mg Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Az31 Mg Alloy ◽  
Similar Texture

Microstructure and texture evolution in the AZ31 Mg alloy subject to equal channel angular pressing (ECAP) have been investigated and correlated with the mechanical properties. When AZ31 Mg alloy was ECAPed up to 8 passes following the route Bc, grain refinement occurred effectively. Texture was also changed during ECAP. The original fiber texture of the extruded AZ31 Mg alloy changed to a new texture component of ] 1 3 2 5 )[ 1 1 01 ( , and the texture of ] 1 3 2 5 )[ 1 1 01 ( orientation was rotated to ] 0 2 5 7 )[ 6 4 13 ( orientation after 6-pass ECAP process. The variation of the strength with the pass number was explained by the texture and grain size. The strength data of AZ31 Mg alloys followed the standard Hall-Petch relationship when the similar texture was retained during the ECAP process. Otherwise the effect of texture on strength was dominant over the strengthening due to grain refinement.

scholarly journals Enhancement of Mechanical and Thermal Properties of Polylactic Acid/Polycaprolactone Blends by Hydrophilic Nanoclay

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Chern Chiet Eng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Hidayah Ariffin ◽  
Wan Md. Zin Wan Yunus ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Polylactic Acid ◽  
Mechanical Analysis ◽  
Basal Spacing ◽  
Mechanical And Thermal Properties ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Thermal Stability Of

The effects of hydrophilic nanoclay, Nanomer PGV, on mechanical properties of Polylactic Acid (PLA)/Polycaprolactone (PCL) blends were investigated and compared with hydrophobic clay, Montmorillonite K10. The PLA/PCL/clay composites were prepared by melt intercalation technique and the composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). FTIR spectra indicated that formation of hydrogen bond between hydrophilic clay with the matrix. XRD results show that shifting of basal spacing when clay incorporated into polymer matrix. TEM micrographs reveal the formation of agglomerate in the composites. Based on mechanical properties results, addition of clay Nanomer PGV significantly enhances the flexibility of PLA/PCL blends about 136.26%. TGA showed that the presence of clay improve thermal stability of blends. DMA show the addition of clay increase storage modulus and the presence of clay Nanomer PGV slightly shift two Tg of blends become closer suggest that the presence of clay slightly compatibilizer the PLA/PCL blends. SEM micrographs revealed that presence of Nanomer PGV in blends influence the miscibility of the blends. The PLA/PCL blends become more homogeneous and consist of single phase morphology.

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