EBSD Analysis of Friction Stir Welded 7136-T76 Aluminum Alloy

2013 ◽  
Vol 203-204 ◽  
pp. 258-261 ◽  
Author(s):  
Izabela Kalemba ◽  
Krzysztof Muszka ◽  
Mirosław Wróbel ◽  
Stanislaw Dymek ◽  
Carter Hamilton

This research addresses the EBSD analysis of friction stir welded 7136-T76 aluminum alloy. The objectives of this study were to evaluate the grain size and their shape, character of grain boundaries in the stirred and thermo-mechanically affected zones, both on the advancing and retreating side as well as to investigate changes in the crystallographic texture. Results of texture analysis indicate the complexity of the FSW process. The texture gradually weakens on moving from the thermo-mechanically affected zone toward the weld center. The stirred zone is characterized by very weak texture and is dominated by high angle boundaries. On the other hand, the thermo-mechanically affected zone exhibits a high frequency of low angle boundaries.

2020 ◽  
Vol 993 ◽  
pp. 116-122
Author(s):  
Kun Yuan Gao ◽  
Bo Li ◽  
Yu Sheng Ding ◽  
Hui Huang ◽  
Sheng Ping Wen ◽  
...  

The hardness and microstructure of friction stir welded (FSW) 6082 aluminum alloy joint were investigated by Vickers microhardness test, optical microscopy (OM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The hardness distribution is in a W shape, and from the base metal to the heat affected zone (HAZ) the hardness decreases from 103 HV to 72 HV, then gradually increases to 84 HV at the nugget zone (NZ). The grains of base metal (BM) are elongated and composed of a great quantity of low-angle grain boundaries. The nugget zon was of quite fine recrystallized grains. For the thermomechanical affected zone (TMAZ), the grain size is a little smaller than that of base metal and some low-angle grain boundaries remain. In the heat affected zone, the grain size was similar to that of the base metal. The β'' phase (Mg5Si6) and Al-Mn-Si particles are dispersed in the base metal. . In the heat affected zone, β'' phase transforms to β' phase (Mg9Si5). The hardness distribution in a W-shape was discussed on the basis of grain size, density of low-angle grain boundary and secondary phases.


Author(s):  
Yijie Hu ◽  
Youping Sun ◽  
Jiangmei He ◽  
Dejun Fang ◽  
Jiaxin Zhu ◽  
...  

Abstract Friction stir processing is an important method for acquiring ultrafine-grained materials. In this paper, 3mm ZK60 magnesium alloy sheet was carried for friction stir processing. The best processing parameters with a small grain size and maximum mechanical properties were obtained by comparing different rotation speeds and processing speeds. Fine recrystallized grains and high-angle grain boundaries were observed in stirring zone under different processing parameters. With increasing rotation speed, the grain size and high-angle grain boundary ratio increase; while with increasing processing speed, the grain size decrease, and the ratio of high-angle grain boundaries increase. When rotation speed and processing speed are 1400 r·min-1 and 100 mm·min-1, the processing plate have the largest ultimate tensile strength are 267.52 Mpa, that reached 84.62% of the base metals, and the yield strength, elongation and grain size are 166.97 Mpa, 15.32 % and 1.12 ± 1.64 µm, respectively. The processing plate has more excellent damping performance than rolled.


Author(s):  
J. W. Matthews ◽  
W. M. Stobbs

Many high-angle grain boundaries in cubic crystals are thought to be either coincidence boundaries (1) or coincidence boundaries to which grain boundary dislocations have been added (1,2). Calculations of the arrangement of atoms inside coincidence boundaries suggest that the coincidence lattice will usually not be continuous across a coincidence boundary (3). There will usually be a rigid displacement of the lattice on one side of the boundary relative to that on the other. This displacement gives rise to a stacking fault in the coincidence lattice.Recently, Pond (4) and Smith (5) have measured the lattice displacement at coincidence boundaries in aluminum. We have developed (6) an alternative to the measuring technique used by them, and have used it to find two of the three components of the displacement at {112} lateral twin boundaries in gold. This paper describes our method and presents a brief account of the results we have obtained.


Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3906 ◽  
Author(s):  
Yang Han ◽  
Xiaoqing Jiang ◽  
Tao Yuan ◽  
Shujun Chen ◽  
Dongxiao Li ◽  
...  

Ultra-thin plates have great potential for applications in aircraft skin, the packaging industry, and packaging of electronic products. Herein, 1 mm-thick 5A06 Al alloy was welded with friction stir welding. The microstructural evolution of the welds was investigated in detail with optical microscopy, scanning electron microscopy, and electron backscatter diffraction. The results showed that the friction stir welds of 1 mm-thick 5A06 Al alloy were well formed without obvious defect and with a minimum thickness reduction of 0.025 mm. Further, the grain size and the proportion of low-angle grain boundaries decreased with decreasing welding speed, because of the increasing degree of dynamic recrystallization. Among all of the welded joints, the welding speed of 100 mm/min yielded the smallest grain size and the highest proportion of high-angle grain boundaries, and thus the best mechanical properties. Specifically, the tensile strength of the joint was greater than that of the base material, while the elongation reached 80.83% of the base material.


2014 ◽  
Vol 699 ◽  
pp. 169-174
Author(s):  
Achmad Zubaydi ◽  
Nurul Muhayat ◽  
Budie Santosa ◽  
Dony Setyawan

Double sided friction stir butt welds on 6 mm thick of 5083 aluminum alloy were produced. Two variants of the weld side combination, different weld side (DS) and same weld side (SS), have been made to investigate the effect of the weld side on mechanical properties.The SS is a double sided welding process that produces advancing side in one plate and retreating side in the other one. On the other hand, the DS is a double sided welding process that causes advancing side and retreating side in each plate. Tensile properties of the joints were evaluated and correlated with macrostructure and hardness. The weld side influenced the macrostructure and mechanical properties of welded joints. The different weld side (DS) had better mechanical properties than the same weld side (SS).


Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 337 ◽  
Author(s):  
Khaled Al-Fadhalah ◽  
Fahad Asi

The present work examined the effect of artificial aging on the microstructure, texture, and hardness homogeneity in aluminum alloy AA6082 subjected to friction stir processing (FSP). Aging was applied to FSP samples at three different temperatures (150 °C, 175 °C, and 200 °C) for a period of 1 h, 6 h, and 12 h. Microstructure analysis using optical Microscopy (OM) and Electron Back-Scattered Diffraction (EBSD) indicated that FSP produced fine equiaxed grains, with an average grain size of 6.5 μm, in the stir zone (SZ) due to dynamic recrystallization. Aging was shown to result in additional grain refinement in the SZ due to the occurrence of recovery and recrystallization with either increasing aging temperature and/or aging time. An optimum average grain size of 3–4 μm was obtained in the SZ by applying aging at 175 °C. This was accompanied by an increase in the fraction of high-angle grain boundaries. FSP provided a simple shear texture with a major component of B fiber. Increasing aging temperature and/or time resulted in the formation of recrystallization texture of a Cube orientation. In addition, Vickers microhardness was evaluated for the FSP sample, indicating a softening in the SZ due to the dissolution of the hardening precipitates. Compared to other aging temperatures, aging at 175 °C resulted in maximum hardness recovery (90 Hv) to the initial value of base metal (92.5 Hv). The hardness recovery is most likely attributed to the uniform distribution of fine hardening precipitates in the SZ when increasing the aging time to 12 h.


2014 ◽  
Vol 59 (1) ◽  
pp. 305-308
Author(s):  
S. Boczkal ◽  
M. Lech-Grega ◽  
B. Płonka

Abstract The structure and properties of AZ61 alloy after deformation by ECAE were characterised. Alloy structure was examined after the successive passes of ECAE process, to study the effect of deformation on the morphology of γ phase precipitates and the size and shape of grains. Based on EBSD analysis, the occurrence of high angle boundaries was stated. An attempt was made to describe the mechanisms that are operating when the deformation route is changed at 300°C in the AZ61 alloy processed by ECAE method. Alloy hardness after the first cycle of deformation was stabilised at the level of 80-90 HB. Based on the hardening curve and the occurrence of high angle grain boundaries (>15°), the possibility of further deformation of the AZ61 alloy was confirmed.


1997 ◽  
Vol 473 ◽  
Author(s):  
Paul R. Besser ◽  
John E. Sanchez ◽  
David P. Fields ◽  
Shekhar Pramanick ◽  
Kashmir Sahota

ABSTRACTNovel metal deposition stack and damascene processing methods have been used to fabricate electrically isolated parallel arrays of 1.0 μm deep aluminum-alloy interconnect trenches varying in width from 0.5 μm to 16 μm. The grain size and crystallographic texture of the Al in these trenches has been characterized using transmission electron microscopy (TEM) and local electron backscattered diffraction (EBSD), respectively. Narrow lines (0.5 and 1.0 μm wide) have a bamboo microstructure, intermediate widths (2.0 μm wide) are nearly bamboo, and wide lines (4.0 μ and wider) are polycrystalline. The <111> texture of the lines degrades with decreasing linewidth. A secondary <100> component is demonstrated and its origin proposed. The electromigration reliability of the narrow damascene Al lines was measured, and the observed enhancement of damascene Al interconnects compared to conventionally-fabricated Al interconnects is correlated with the microstructure.


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