scholarly journals Metallographic organization and tensile properties of FSSP-modified H62 copper alloy surface

2020 ◽  
Vol 29 ◽  
pp. 2633366X2092702
Author(s):  
Weiwei Song ◽  
Xiaojing Xu ◽  
Shengrong Liu ◽  
Jiafei Pu ◽  
Hongfeng Wang
Keyword(s):  
Grain Size ◽  
Base Metal ◽  
Copper Alloy ◽  
Boundary Region ◽  
Alloy Sheet ◽  
Alloy Surface ◽  
Surface Processing ◽  
Friction Stir ◽  
Equiaxed Grains ◽  
Hardness Values

In this study, the surface of friction stir surface processing (FSSP)-modified copper alloy was altered by different passes of modification and lower pressure after selecting FSSP process parameters. The results showed that the grain size of the modified copper alloy surface was refined under various processes. In the modified section, the grains changed from fine equiaxed grains to rolling strips from the surface layer to the bottom of copper alloy sheet. FSSP could change the surface metallographic organization but could not change the internal structure of the sheet. The hardness values of samples obtained under various processes were higher than those of base metal, but the hardness of modified boundary region was slightly lower than that of base metal. The tensile strength of samples obtained under various processes was higher than that of base metal. Among them, FSSP was the best after one pass of modification, followed by two passes, and the worst was three passes. Most of the stretches appeared on the advancing side, and only a few appeared on the retreating side. The tensile parts had a honeycomb-type morphology, with a ductile fracture mode.

Friction Stir Welding of Oxygen Free Copper and 60%Cu-40%Zn Copper Alloy

2008 ◽  
Vol 580-582 ◽  
pp. 447-450
Author(s):  
Hwa Soon Park ◽  
Byung Woo Lee ◽  
Taichi Murakami ◽  
Kazuhiro Nakata ◽  
Masao Ushio
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Base Metal ◽  
Welding Speed ◽  
Copper Alloy ◽  
Rotation Speed ◽  
Friction Stir ◽  
Wide Range ◽  
Hardness Values ◽  
Tool Rotation

The mechanical properties of the friction stir welds of the oxygen free copper (OFC) and 60%Cu-40%Zn copper alloy(60/40 brass) were investigated. The defect-free welds were obtained in a relatively wide range of welding conditions; the tool rotation speed had rpm of 1000 to 2000 in the OFC and 1000 to 1500 in the 60/40 brass, with the welding speed of 500 to 2000 mm/min. The SZ hardness values of the OFC welds were almost the same or slightly lower than those of the base metal. However, the SZ hardness values of the 60/40 brass in all welding conditions were much higher than those of the base metal. The SZ hardness values of both metals increase with a decrease in heat input. The tensile properties of the all-SZ showed relative correspondence to the variation of the SZ hardness values.

scholarly journals Aging Behavior of Aluminum Alloy 6082 Subjected to Friction Stir Processing

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 337 ◽  
Author(s):  
Khaled Al-Fadhalah ◽  
Fahad Asi
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Aging Time ◽  
Friction Stir Processing ◽  
Aging Temperature ◽  
Friction Stir ◽  
Average Grain Size ◽  
Different Temperatures ◽  
Equiaxed Grains ◽  
Electron Back Scattered Diffraction

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.

scholarly journals The Applicability of Die Cast A356 Alloy to Additive Friction Stir Deposition at Various Feeding Speeds

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6018
Author(s):  
Bandar Alzahrani ◽  
Mohamed M. El-Sayed Seleman ◽  
Mohamed M. Z. Ahmed ◽  
Ebtessam Elfishawy ◽  
Adham M. Z. Ahmed ◽  
...  
Keyword(s):  
Grain Size ◽  
Cast Alloy ◽  
A356 Alloy ◽  
Deposition Process ◽  
Al Alloy ◽  
Cast Material ◽  
Mean Values ◽  
Friction Stir ◽  
Eutectic Si ◽  
Hardness Values

In the current investigation, additive friction stir-deposition (AFS-D) of as-cast hypoeutectic A356 Al alloy was conducted. The effect of feeding speeds of 3, 4, and 5 mm/min at a constant rotational speed of 1200 rpm on the macrostructure, microstructure, and hardness of the additive manufacturing parts (AMPs) was investigated. Various techniques (OM, SEM, and XRD) were used to evaluate grain microstructure, presence phases, and intermetallics for the as-cast material and the AMPs. The results showed that the friction stir deposition technique successfully produced sound additive manufactured parts at all the applied feeding speeds. The friction stir deposition process significantly improved the microstructure of the as-cast alloy by eliminating porosity and refining the dendritic α-Al grains, eutectic Si phase, and the primary Si plates in addition to intermetallic fragmentation. The mean values of the grain size of the produced AMPs at the feeding speeds of 3, 4, and 5 mm/min were 0.62 ± 0.1, 1.54 ± 0.2, and 2.40 ± 0.15 µm, respectively, compared to the grain size value of 30.85 ± 2 for the as-cast alloy. The AMPs exhibited higher hardness values than the as-cast A356 alloy. The as-cast A356 alloy showed highly scattered hardness values between 55 and 75.8 VHN. The AMP fabricated at a 3 mm/min feeding speed exhibited the maximum hardness values between 88 and 98.1 VHN.

Investigations on the Hardness Distribution and Microstructure of Friction-Stir-Welded 6082 Aluminum Alloy

2020 ◽  
Vol 993 ◽  
pp. 116-122
Author(s):  
Kun Yuan Gao ◽  
Bo Li ◽  
Yu Sheng Ding ◽  
Hui Huang ◽  
Sheng Ping Wen ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Grain Boundaries ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Hardness Distribution ◽  
Secondary Phases ◽  
Friction Stir ◽  
Β Phase ◽  
6082 Aluminum Alloy

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.

Synergetic Effect of ECAP and Friction Stir Welding on Microstructure and Mechanical Properties of Aluminium Sheets

2010 ◽  
Vol 667-669 ◽  
pp. 505-510
Author(s):  
Ilya Nikulin ◽  
Alla Kipelova ◽  
Sergey Malopheyev ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Friction Stir Welding ◽  
Base Metal ◽  
Synergetic Effect ◽  
Aluminum Matrix ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

Friction stir welding (FSW) was used to join the submicrocrystalline (SMC) grained Al-Cu-Mg-Ag sheets produced by equal channel angular pressing (ECAP) followed by hot rolling (HR). The effect of SPD and FSW on the microstructure and mechanical properties in the zone of base metal, as well as in the stirred zone (SZ) were examined. In addition, effect of standard heat treatment on microstructure and mechanical properties in these zones was considered. A refined microstructure with an average grain size of ~ 0.6 m and a portion of high-angle grain boundaries (HAGBs) of ~0.67 was produced in sheets by ECAP followed by HR at 250°C. The microcrystalline grained structure with average grain size of ~2.3 mm was found in joint weld. The moderate mechanical properties were revealed in SMC sheets and joint welds. Heat treatment considerably increases strength of the base metal as well as the joint welds. The higher strength of the alloy after T6 temper is attributed to the dense precipitations of  dispersoids having plate-like shape which are uniformly distributed within aluminum matrix. It was observed that FSW can produce full strength weld both in the tempered and in the un-tempered conditions.

Microstructure and Texture Evolution during Friction Stir Processing of AZ31 Mg Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 1195-1200 ◽  
Author(s):  
Ren Long Xin ◽  
Bo Li ◽  
Qing Liu
Keyword(s):  
Grain Size ◽  
Texture Evolution ◽  
Base Material ◽  
Alloy Sheet ◽  
Electron Back Scatter Diffraction ◽  
Mg Alloy ◽  
Gradual Change ◽  
Friction Stir ◽  
Az31 Mg Alloy ◽  
Average Grain Size

In this study, a well-textured AZ31 Mg alloy sheet was friction stir (FS) processed, and the microstructure and texture evolution in various regions of the processed alloy were examined by optical microscopy (OM) and electron back scatter diffraction (EBSD). The results showed that the grain size in the FS zone was significantly refined compared to that in the base material (BM). The average grain size in the thermomechanically affected zone (TMAZ) and heat-affected zone (HAZ) was comparable with that in the BM. There is a gradual change of local texture from BM to FS zone due to plastic flow together with heating input during the FS processing. The <0002> direction was roughly parallel to the cylindrical pin surface normal of the FS zone. The <0002> direction in the HAZ is similar to that in the BM, but more diffuse. The <0002> direction in the TMAZ was tilted 25~30o away from the ND and there is a distinct boundary between the FS zone and TMAZ at the advancing side which introduced an incompatibility between the FS zone and TMAZ. This might explain the fact that the transverse FS processed Mg alloys commonly fracture at the advancing side during tensile tests.

Study on the corrosion of copper alloy by friction stir surface processing

2016 ◽  
Vol 63 (3) ◽  
pp. 190-195 ◽  
Author(s):  
Song Weiwei ◽  
Xiaojing Xu ◽  
Dunwen Zuo ◽  
Jianli Wang
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Copper Alloy ◽  
Rotation Speed ◽  
Electrochemical Corrosion ◽  
Test Results ◽  
Surface Processing ◽  
Content Type ◽  
Friction Stir ◽  
Modified Surface

Purpose This paper aims to investigate the modification of surface of a copper alloy by friction stir surface processing (FSSP). Design/methodology/approach The metallographic condition of the surface modification was observed using microscopy. Electrochemical corrosion tests were carried out on the modified surface and the corroded surface was observed by scanning electron microscopy (SEM). Findings The test results showed that FSSP resulted in refinement of the surface grains of the copper alloy. The degree of refinement was increased with rotation speed and increased in the descending distance of the stirring tool. The corrosion resistance of the modified surface was superior to the base metal except for the surface generated by a rotation speed of 800 rpm and a descending distance 0.1 mm. For the surface modification of the rotation speed of 800 rpm, its corrosion resistance was lower than for the other two rotation speeds. When the rotation speed is specified, the corrosion resistance is improved with increased descending distance. When the descending distance is specified, the corrosion resistance is improved with the rotation speed. Originality/value In this study, it was confirmed that the corrosion resistance of the surface modification was best at the rotation speed 1200 rpm and descending distance 0.2 mm.

scholarly journals FEM Research on Welding Thermal Deformation of Copper Alloy Sheet and Optimization of Welding Sequence

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1287
Author(s):  
Mingxin Yuan ◽  
Suodong Liu ◽  
Hongwei Sun ◽  
Yunqiang Gao ◽  
Xianling Dai ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Base Metal ◽  
Copper Alloy ◽  
Thermal Deformation ◽  
Alloy Sheet ◽  
Welding Sequence ◽  
Change Trend ◽  
Stress And Deformation ◽  
Residual Stress And Deformation

To reduce the residual stress and deformation of the copper alloy sheet after welding, and improve the welding quality of the copper alloy sheet, the finite element method (FEM) research on welding thermal deformation and welding sequence optimization was carried out. First, a finite element model of copper alloy sheet welding was established based on ANSYS, the mechanical property parameters of the model at high temperature were determined, and the thermal–structural coupling calculation was performed on the model. Then, the change trend and magnitude of the residual stress and deformation of the model after welding were analyzed. Finally, different welding sequence schemes were designed, and numerical simulation calculations were carried out. The results of the welding sequence solution show that the change trend of the residual stress after welding of the base metal under different welding sequences is basically the same; repeated heating of the base metal at the same position causes large residual stress; the weldment vertical plate is subjected to opposing forces in the x-axis and y-axis directions at the same time. Among four welding schemes, the welding scheme that alternately welds symmetrically from the start and end positions of the weld seam to the middle position of the plate causes the least welding deformation. Compared with the other three schemes, its deformation reduces by 26.6%, 18.3%, and 19.4%, respectively.

Microstructural Evolution of Cast Mg-Al-Ca Alloy during Friction Stir Processing

2007 ◽  
Vol 539-543 ◽  
pp. 3739-3744 ◽  
Author(s):  
Da Tong Zhang ◽  
Mayumi Suzuki ◽  
Kouichi Maruyama
Keyword(s):  
Mechanical Property ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Base Metal ◽  
Microstructural Evolution ◽  
Friction Stir Processing ◽  
Stir Zone ◽  
Plate Surface ◽  
Friction Stir ◽  
Microstructure And Mechanical Property

A thixomoulded magnesium alloy containing thermally stable Al2Ca phase was friction stir processed, and its microstructure and mechanical property were investigated. In friction stir zone, the cast structure of the base metal is replaced by fine magnesium grains containing fine dispersoides of Al2Ca. Due to the refined grain size of 0.8-1 μm, hardness of friction stir zone is higher than that of base metal. Texture was developed at top and bottom surfaces, (0002) being parallel to the plate surface, whereas (0001) plane is randomly oriented in the center of friction stir zone.

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