DEVELOPMENT OF CRYSTALLOGRAPHIC TEXTURE AND GRAIN REFINEMENT IN THE ALUMINUM LAYER OF CU-AL-CU TRI-LAYER COMPOSITE DEFORMED BY EQUAL CHANNEL ANGULAR EXTRUSION

2012 ◽  
Vol 05 ◽  
pp. 325-334 ◽  
Author(s):  
B. TOLAMINEJAD ◽  
A.KARIMI TAHERI ◽  
M. SHAHMIRI ◽  
H. ARABI
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Equal Channel Angular Extrusion ◽  
Cell Formation ◽  
Single Layer ◽  
Ultrafine Grain ◽  
Aluminum Layer ◽  
Dislocation Interaction ◽  
Copper Aluminum ◽  
Copper Composite

The present research is concerned with the aluminum layer of a loosely packed tri-layer copper-aluminum-copper composite deformed by ECAE process. Electron back scattered diffraction (EBSD), transmission electron microscope, and X-ray technique were employed to investigate the detailed changes occurring in the microtexture, microstructure (cell size and misorientation), and dislocation density evolution during consecutive passes of ECAE process performed on the composite based on route Bc. According to tensile test results, the yield stress of the aluminum layer was increased significantly after application of ECAE throughout the four repeated passes and then slightly decreased. An ultrafine grain size within the range of 500-600 nm was obtained in the Al layer by increasing the thickness of copper layers. It was observed that the reduction of grain size in the aluminum layer is nearly 57% more than that of an ECAE-ed single layer aluminum billet. Also, the grain refinement of the aluminum layer is accelerated throughout 8 passes. This observation was attributed to the higher rate of dislocation interaction, cell formation and texture development during the ECAE of the composite compared to those of the single billet.

Microstructure and Mechanical Properties Resulting from Cold Rolling of Equal Channel Angular Extruded Commercial Purity Copper

2006 ◽  
Vol 503-504 ◽  
pp. 733-738
Author(s):  
A. Krishnaiah ◽  
Chakkingal Uday ◽  
P. Venugopal
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cold Rolling ◽  
Equal Channel Angular Extrusion ◽  
Pure Copper ◽  
Ultrafine Grain ◽  
Ultrafine Grain Size ◽  
Ultrafine Grained ◽  
Angular Extrusion ◽  
Initial Processing

Equal channel angular extrusion (ECAE) is a processing method for introducing an ultrafine grain size into a material. In the present study, a two-step severe plastic deformation process was used to produce ultrafine grained copper with significantly enhanced strength. Equal channel angular extrusion was first used to refine the grain size of copper samples. The copper samples were further processed by cold rolling (CR) to a strain of 0.67 (about 50% reduction). This two-step process produced ultrafine grained copper with strengths higher than those of pure copper processed through ECAE only. This paper reports the microstructures and mechanical properties of the copper specimens processed by a combination of room temperature ECAE and CR. The effectiveness of initial processing by ECAE prior to cold rolling is discussed.

Microstructure and Wear Properties of GCr15 Alloy Produced by Equal Channel Angular Extrusion

2011 ◽  
Vol 211-212 ◽  
pp. 661-665
Author(s):  
Guo Quan Xiang ◽  
Min Xin Zheng ◽  
Lian Qing Ji
Keyword(s):  
Grain Size ◽  
Mass Loss ◽  
Grain Refinement ◽  
Equal Channel Angular Extrusion ◽  
Optical Microscope ◽  
Wear Properties ◽  
Gcr15 Steel ◽  
Angular Extrusion

GCr15 alloy produced by hot-forged is subjected to equal channel angular extrusion (ECAE) process at 950°C. The microstructure of GCr15 steel via ECAE and annealed is studied by an optical microscope. The effect of ECAE and annealing on the wear properties of the alloy is also investigated. The results show that the grain size reduced from 50 mm to 10 mm via one pass ECAE, and the hardness of the alloy is increased. The wear mass loss of the alloy is greatly reduced due to the grain-refinement after ECAE and annealing.

Plastic Behavior of Metals at Large Strains: Experimental Studies Involving Simple Shear

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
E. F. Rauch
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Simple Shear ◽  
Equal Channel Angular Extrusion ◽  
Experimental Studies ◽  
Low Carbon Steel ◽  
Stage Iv ◽  
Large Strains ◽  
Plastic Behavior ◽  
Low Carbon

Two experimental devices that promote simple shear are used to investigate the plastic behavior of metals under very large strains. First, researches on the anisotropic behaviors of sheets of metals performed with the help of the planar simple shear test are reviewed. In particular, it is shown that, with this device, stage IV may be reached and analyzed on polycrystals as well as on single crystals. The second part is devoted to equal channel angular extrusion, which is known to promote grain refinement after several passes. A direct comparison of the crystallographic textures measured on sheared and on extruded samples confirms that the extrusion promotes massively simple shear. Besides, the grain refinement is measured with a dedicated transmission electron microscopy (TEM) attachment. It is shown that the grain size decreases regularly for a low carbon steel as well as for copper, down to around 1 μm. It is argued that the sustained hardening in stage IV is a mechanical signature of the grain size decrease. The trend is interpreted and reproduced quantitatively with the help of a simple modeling approach.

Microstructure and Tensile Properties of Magnesium Alloy Containing Quasicrystallines Processed by Equal-Channel-Angular-Extrusion

2005 ◽  
Vol 475-479 ◽  
pp. 469-472 ◽  
Author(s):  
Ming Yi Zheng ◽  
Xiao Guang Qiao ◽  
Shi Wei Xu ◽  
Kun Wu ◽  
Shigeharu Kamado ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Tensile Properties ◽  
Grain Refinement ◽  
Equal Channel Angular Extrusion ◽  
High Strength ◽  
Good Combination ◽  
Mg Alloy ◽  
High Ductility ◽  
Angular Extrusion

Equal channel angular extrusion (ECAE) was performed on as-cast ZW1101 (Mg-11wt%Zn- 0.9wt%Y) Mg alloy containing quasicrystallines. The grain size of α-Mg was effectively refined, and coarse eutectic quasicrystalline phases were broken and dispersed in the alloy by ECAE. The alloy processed by ECAE exhibited a good combination of high strength and high ductility, which is due to the grain refinement and fine dispersed quasicrystallines in the alloy.

Effect of Grain Size on Cross Wedge Rolling of Micro Copper Rod

2014 ◽  
Vol 622-623 ◽  
pp. 905-911 ◽  
Author(s):  
Chao Cheng Chang ◽  
Yao Sheng Hsiao
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Material Flow ◽  
Equal Channel Angular Extrusion ◽  
Curvature Radius ◽  
Cross Wedge Rolling ◽  
Rolling System ◽  
Forming Load ◽  
Angular Extrusion ◽  
The Cross

This study investigated the effect of grain size on the cross wedge rolling of micro copper rod. Annealing techniques and equal channel angular extrusion were employed to refine the grains of copper, after which the treated copper was machined to prepare the cylindrical billets with 1 mm diameter for conducting experiments. The billets were rolled between a pair of the dies fixed in a developed cross wedge rolling system to form micro copper rods. The results show that the developed system was able to successfully produced micro copper rods. The grain refinement led to a higher hardness and thus a greater forming load. The rod with fine grans had a larger concave curvature radius of the end face. The grain size clearly influences the material flow in the cross wedge rolling processes of the micro copper rod.

ACHIEVING ULTRAFINE GRAIN SIZE IN Mg-Al-Zn ALLOY BY COLD DRAWING

2009 ◽  
Vol 23 (06n07) ◽  
pp. 927-933 ◽  
Author(s):  
HONGYING CHAO ◽  
YANG YU ◽  
ERDE WANG
Keyword(s):  
Grain Size ◽  
Strain Hardening ◽  
Grain Refinement ◽  
Annealing Temperature ◽  
High Strength ◽  
Cold Drawing ◽  
Ultrafine Grain ◽  
Area Reduction ◽  
Ultrafine Grain Size ◽  
Cold Area

Ultrafine-grain size of ~1µm was achieved in an AZ31B Mg alloy wires with high strength prepared by cold drawing and subsequent annealing in the present study. Effects of cold-drawn area reduction (CAR) on strain hardening, recrystallized grain refinement and annealing temperature were investigated. The results showed that the maximum cold area reduction as high as 65.1% could be reached at room temperature, which resulted in the notable strain hardening, grain refinement and the decrease of annealing temperature.

scholarly journals Effect of Vanadium Reinforcement on the Microstructure and Mechanical Properties of Magnesium Matrix Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 806
Author(s):  
Liqing Sun ◽  
Shuai Sun ◽  
Haiping Zhou ◽  
Hongbin Zhang ◽  
Gang Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Milling Process ◽  
Mg Alloy ◽  
Matrix Composites ◽  
Magnesium Matrix Composites ◽  
Pinning Effect ◽  
Average Grain Size ◽  
The Matrix ◽  
Hot Press Sintering

In this work, vanadium particles (VP) were utilized as a novel reinforcement of AZ31 magnesium (Mg) alloy. The nanocrystalline (NC) AZ31–VP composites were prepared via mechanical milling (MM) and vacuum hot-press sintering. During the milling process, the presence of VP contributed to the cold welding and fracture mechanism, resulting in the acceleration of the milling process. Additionally, increasing the VP content accelerated the grain refinement of the matrix during the milling process. After milling for 90 h, the average grain size of AZ31-X wt % Vp (X = 5, 7.5, 10) was refined to only about 23 nm, 19 nm and 16 nm, respectively. In the meantime, VP was refined to sub-micron scale and distributed uniformly in the matrix, exhibiting excellent interfacial bonding with the matrix. After the sintering process, the average grain size of AZ31-X wt % VP (X = 5, 7.5, 10) composites still remained at the NC scale, which was mainly caused by the pinning effect of VP. Besides that, the porosity of the sintered composites was no more than 7.8%, indicating a good densification effect. As a result, there was little difference between the theoretical and real density. Compared to as-cast AZ31 Mg alloy, the microhardness of sintered AZ31-X wt % VP (X = 5, 7.5, 10) composites increased by 65%, 87% and 96%, respectively, owing to the strengthening mechanisms of grain refinement strengthening, Orowan strengthening and load-bearing effects.

Effect of Composite Master Alloy on Mechanical Properties and Electrochemical Corrosion of ZL101 Alloy

2013 ◽  
Vol 749 ◽  
pp. 407-413
Author(s):  
Hong Xu ◽  
Xin Zhang ◽  
Ji Ping Ren ◽  
Min Peng ◽  
Shi Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Grain Refinement ◽  
Master Alloy ◽  
Mass Fraction ◽  
Electrochemical Corrosion ◽  
Corrosion Performance ◽  
Obvious Effect ◽  
Mechanical Properties And Corrosion

The mechanical properties and corrosion performances of the ZL101 alloy modified by the composite master alloy were investigated. The results showed that the master alloy had not only obvious effect of grain refinement, but also a significant role in refining dendrite grain of ZL101 alloy. The grain size decreased dramatically from 150μm to 62μm when the addition of composite master alloy is up to 0.5%(mass fraction) and the temperature is 720 for 30 minutes,. Its tensile strength and elongation increased by 27% and 42% respectively. The grain refinement of ZL101 alloy decreased its corrosion performance. The morphology of Si changed into globular from needle modified by NaF, instead of AlTiB.

Computation on continuous grain refinement in AA1050 aluminum during repetitive tube expansion and shrinking technique

2015 ◽  
Vol 232 (4) ◽  
pp. 307-318
Author(s):  
H Jafarzadeh ◽  
K Abrinia
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Grain Size ◽  
Finite Element ◽  
Dislocation Density ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Half Cycle ◽  
Tube Expansion ◽  
Element Method

The microstructure evolution during recently developed severe plastic deformation method named repetitive tube expansion and shrinking of commercially pure AA1050 aluminum tubes has been studied in this paper. The behavior of the material under repetitive tube expansion and shrinking including grain size and dislocation density was simulated using the finite element method. The continuous dynamic recrystallization of AA1050 during severe plastic deformation was considered as the main grain refinement mechanism in micromechanical constitutive model. Also, the flow stress of material in macroscopic scale is related to microstructure quantities. This is in contrast to the previous approaches in finite element method simulations of severe plastic deformation methods where the microstructure parameters such as grain size were not considered at all. The grain size and dislocation density data were obtained during the simulation of the first and second half-cycles of repetitive tube expansion and shrinking, and good agreement with experimental data was observed. The finite element method simulated grain refinement behavior is consistent with the experimentally obtained results, where the rapid decrease of the grain size occurred during the first half-cycle and slowed down from the second half-cycle onwards. Calculations indicated a uniform distribution of grain size and dislocation density along the tube length but a non-uniform distribution along the tube thickness. The distribution characteristics of grain size, dislocation density, hardness, and effective plastic strain were consistent with each other.

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