scholarly journals Microstructure and Its Influence on the Welding Quality of 6063 Aluminum Alloy Porthole Die Extrusion

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6584
Author(s):  
Shikang Li ◽  
Luoxing Li ◽  
Zhiwen Liu ◽  
Guan Wang
Keyword(s):  
Aluminum Alloy ◽  
Dynamic Recrystallization ◽  
Welding Quality ◽  
3D Numerical Modeling ◽  
Porthole Die ◽  
Average Grain Size ◽  
The Matrix ◽  
6063 Aluminum Alloy ◽  
Ram Speed

Extrusion experiments and 3D numerical modeling were conducted to investigate the dynamic recrystallization and welding quality of a 6063 aluminum alloy hollow square tube extruded by a porthole die at the ram speeds of 3 mm/s, 7 mm/s, 9 mm/s and 11 mm/s. The results showed that average grain size of hollow square tube extruded at the ram speed of 7 mm/s was the smallest. The profile extruded at the ram speed of 3 mm/s exhibited the highest expansion ratio. Dynamic recrystallization (DRX) fractions were highly variable at different ram speeds. DRX fractions in the matrix zones were higher than those in the welding zones, resulting in smaller grain sizes in the matrix zones. Mechanical properties in the welding zones and matrix zones was different. A local strain concentration would occurred during expansion, which would affect the welding quality. Finally, it was found that the uniform microstructure near the welding line would also affect the welding quality.

scholarly journals Hot Deformation Behavior and Microstructure Evolution of 6063 Aluminum Alloy Modified by Rare Earth Y and Al-Ti-B Master Alloy

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4244 ◽  
Author(s):  
Wanwu Ding ◽  
Xiaoxiong Liu ◽  
Xiaoyan Zhao ◽  
Taili Chen ◽  
Haixia Zhang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Rare Earth ◽  
Dynamic Recrystallization ◽  
Master Alloy ◽  
Hot Deformation ◽  
True Strain ◽  
Constitutive Models ◽  
Hot Workability ◽  
Continuous Dynamic Recrystallization ◽  
6063 Aluminum Alloy

The hot deformation behaviors of the new 6063 aluminum alloy modified by rare earth Y and Al-Ti-B master alloy were studied through isothermal hot compression experiments on the Gleeble-3800 thermal simulator. By characterizing the flow curves, constitutive models, hot processing maps, and microstructures, we can see from the true stress–true strain curves that the flow stress decreases with the increase of deformation temperature and the decrease of strain rate. Through the calculation of the constitutive equation, we derived that the activation energy of the new composite modified 6063 aluminum alloy is 224.570 KJ/mol. we roughly obtained its excellent hot processing range of temperatures between 470–540 °C and the strain rates of 0.01–0.1 s−1. The verification of the deformed microstructure shows that with the decrease of lnZ, the grain boundary changes from a low-angle one to a high-angle one and the dynamic recrystallization is dominated by geometric dynamic recrystallization and continuous dynamic recrystallization. Analysis of typical samples at 480 °C/0.01 s−1 shows that the addition of rare earth Y mainly helps form Al3Y5 and AlFeSiY phases, thus making the alloy have the performance of high-temperature recrystallization, which is beneficial to the hot workability of the alloy.

Evaluation on Microstructure of Aluminum Alloys Dedicated to Plasma Etcher

2011 ◽  
Vol 689 ◽  
pp. 343-349
Author(s):  
Zhi Hui Zhang ◽  
Shu Feng Liu ◽  
Ze Ming Sun ◽  
Xiao Dong Yan
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Anodic Oxidation ◽  
Scientific Basis ◽  
Secondary Phases ◽  
6061 Aluminum Alloy ◽  
Close Relationship ◽  
The Matrix ◽  
Hole Defects

The relationship between microstructure and anodic oxidation film on 6061 aluminum alloy dedicated to plasma etcher were mainly studied by OM, SEM and TEM. The results show that the quality of anodic oxidation film has close relationship with the microstructure of materials, the distribution of element and the morphology of secondary phases. The microstructure of foreign 6061 aluminum alloy is uniform, and there are not obviously segregation and cavity. Two kinds of secondary phases disperse over the grain, one is rich-Fe phase, and the other is Mg2Si. Certainly there are also few secondary phases distributing along the grain boundary. The sizes of all secondary phases are almost below 5mm. The size of rich-Fe phases in homemade aluminum alloys are about from 2mm to 15mm, these big-size phases will bring pin-hole defects, which form some channels sending F+ etc. into the matrix of aluminum alloy, then not only the equipment will be destroyed at last, but also products will be polluted. The evaluation on microstructure of aluminum alloy will provide scientific basis for nationalization of plasma etcher.

scholarly journals Simulation and Experiment of New Ultrasonic Vibration Network

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiwen Chen ◽  
Xiaoqian Li ◽  
Weihua Gui ◽  
Luca Landi
Keyword(s):  
Aluminum Alloy ◽  
Power Spectrum ◽  
Frequency Spectrum ◽  
Ultrasonic Vibration ◽  
Spectrum Efficiency ◽  
Vibration Source ◽  
Aluminum Alloy Casting ◽  
Alloy Casting ◽  
Average Grain Size

A reasonable ultrasonic vibration network can improve the casting quality of aluminum alloy. Ultrasonic vibration network based on a honeycomb structure has been designed, referred to as a new vibration network. The new vibration network can solve the problems of nonuniform distribution of power ultrasonic wave, small working area and low volume of ultrasonic vibration network, low efficiency of the frequency spectrum and power spectrum, and poor quality of aluminum alloy casting. The number of vibration nodes can be determined based on the number of layers of the vibration source nodes. The edge length of regular hexagonal honeycomb cells can be determined based on the size of the casting ingot. The output power and resonant frequency of the ultrasonic vibration network can be adjusted in real time according to the status of aluminum alloy melt. A seven-node new ultrasonic network and a four-node ultrasonic network with a traditional structure were selected and used in the experiment and simulation of a 500 mm diameter 2219 aluminum alloy ingot. In comparison with the traditional four-node ultrasonic network, the effective volume and area, frequency spectrum efficiency, and comprehensive coverage probability of the seven-node new ultrasonic vibration network increased by 34.06%, 23.12%, 17.25%, and 0.308, respectively. The difference between the desired value and average efficiency of the power spectrum was 0.292 W/cm2, and the average grain size of aluminum alloy decreased by 34.98 microns. These results indicate that the efficiency of ultrasonic-vibration-assisted casting system and the quality of aluminum alloy casting can be improved using the new ultrasonic vibration network.

scholarly journals Micro-Extrusion Process And Microstructure Evolution of Miniature Heat Pipe In 6063 Aluminum Alloy

2021 ◽  
Author(s):  
Yongda Liu ◽  
Jie Xu ◽  
Zhengwu Zhang ◽  
Gang Liu ◽  
Debin Shan ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Size Effect ◽  
Heat Pipe ◽  
Microstructure Evolution ◽  
Material Flow ◽  
Shape Control ◽  
Extrusion Process ◽  
Extrusion Ratio ◽  
6063 Aluminum Alloy ◽  
Ram Speed

Abstract Micro-extrusion process of miniature heat pipe with axial micro grooves is particularly difficult due to ultra-large extrusion ratio and complex cross-sectional shape. In this study, the shape control of a miniature heat pipe in 6063 aluminum alloy with boundary dimension of 5×4 mm has been successfully realized during micro-extrusion. Micro-extrusion process and microstructure evolution of the miniature heat pipe were investigated by the combination of finite element (FE) analysis with experiments. The results show that material flow deformation behavior during micro-extrusion is highly affected by size effect, and lower ram speed is conductive to forming integrity, dimension accuracy and surface quality of the heat pipe profile. The primary mechanism for micro-extrusion failure of micro-grooves is severely more uneven material flow between the micro rib and base region at higher ram speed, which is caused by size effect and results in shear deformation and even fractures of micro rib. Further research shows that, compared to the extrusion using as-cast billets, much coarser grains were obtained after micro-extrusion using as-extruded billets at an ultra-large extrusion ratio of 205. Besides that, the entirely different texture components after extrusion were obtained instead of the typical < 100 > //ED or < 111 > //ED fiber texture components. These atypical texture components can be regarded as texture deviating from ideal texture by a certain angle (15° or 20°) along φ axis or φ1 axis.

scholarly journals Process Performance Analysis and Improvement for the Manufacture of 6063 Aluminum Alloy

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 605 ◽  
Author(s):  
Chang-Hsien Hsu
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Chemical Elements ◽  
Pure Aluminum ◽  
Ferrous Metal ◽  
International Standards ◽  
Quality Analysis ◽  
6063 Aluminum Alloy

As industrial manufacturing technologies continuously improve, many conventional industrial materials are struggling to meet the needs of today’s industries. Aluminum alloys are currently the most extensively used non-ferrous metal in the industry, whose properties include corrosion resistance, high strength, and high ductility. As a result, they are widely used in many products, such as doors and windows, vehicles, and electronics. Pure aluminum though, is a very soft, silver-white metal, so to increase its strength, aluminum alloy manufacturers add in various chemical elements (such as magnesium, silicon, and zinc) according to international standards, and then adjust the proportions based on customer needs. If the chemical element composition does not meet specification requirements, it will affect the quality of the aluminum alloy product or even delay delivery and subsequently impact the operational performance of the manufacturer. To ensure and increase aluminum alloy quality, this study used a combined Six Sigma quality index (SSQI), Qpc, to develop a multi-characteristic quality analysis model (MCQAM) with five steps for the aluminum alloy industry. A practical example with a manufacturer specializing in producing 6063 aluminum alloys in Taiwan is given to demonstrate the effectiveness and feasibility of this proposed approach. The result shows that the proposed method not only effectively improves the quality of 6063 aluminum alloy, but also enhances its performance and capability (that is, corrosion resistance increases by 17%, strength increases by 8%, and stiffness increases by 3%). Finally, future works are also discussed in this context.

Influence of the Microstructure Al-12%Si Alloy on the Properties of the Oxide Layer Formed with MAO

2016 ◽  
Vol 870 ◽  
pp. 481-486 ◽  
Author(s):  
S.K. Kiseleva ◽  
L.I. Zaynullina ◽  
N.Y. Dudareva
Keyword(s):  
Aluminum Alloy ◽  
Thermal Treatment ◽  
Microarc Oxidation ◽  
High Hardness ◽  
Matrix Solution ◽  
Initial Microstructure ◽  
The Matrix ◽  
Alloy Microstructure ◽  
Silicon Particles

The quality of coating on the high-silicon aluminum alloy Al-12%Si depending on the initial microstructure of the samples has been investigated. The method of microarc oxidation (MAO) has been used for coating. The quality of coating was evaluated by the thickness and microhardness of the formed layer. The initial microstructure of aluminum alloy samples was varied by distribution of silicon particles in the volume of the matrix solution. The possibility of obtaining a high-hardness protective coating on the alloy Al-12%Si by the MAO method has been shown. The influence of the alloy microstructure on the microhardness and thickness of coatings has been established. It has been shown that the deformation thermal treatment of Al-12%Si alloy samples before MAO leads to deterioration in the quality of the formed layer. A model of the influence of the silicon particles distribution on the quality of the micro-layer has been represented for explanation of the observed effect. The increase of microhardness in coatings with a greater thickness has been revealed.

The microstructure change of low-carbon electrical steels by residual aluminum

1989 ◽  
Vol 47 ◽  
pp. 286-287
Author(s):  
C.K. Hou ◽  
C.T. Hu ◽  
Sanboh Lee
Keyword(s):  
Annealing Treatment ◽  
Low Carbon ◽  
Electrical Steels ◽  
Vacuum Degassing ◽  
Spherical Inclusions ◽  
Residual Aluminum ◽  
Average Grain Size ◽  
The Matrix ◽  
Fine Size ◽  
To Come

The fully processed low-carbon electrical steels are generally fabricated through vacuum degassing to reduce the carbon level and to avoid the need for any further decarburization annealing treatment. This investigation was conducted on eighteen heats of such steels with aluminum content ranging from 0.001% to 0.011% which was believed to come from the addition of ferroalloys.The sizes of all the observed grains are less than 24 μm, and gradually decrease as the content of aluminum is increased from 0.001% to 0.007%. For steels with residual aluminum greater than 0. 007%, the average grain size becomes constant and is about 8.8 μm as shown in Fig. 1. When the aluminum is increased, the observed grains are changed from the uniformly coarse and equiaxial shape to the fine size in the region near surfaces and the elongated shape in the central region. SEM and EDAX analysis of large spherical inclusions in the matrix indicate that silicate is the majority compound when the aluminum propotion is less than 0.003%, then the content of aluminum in compound inclusion increases with that in steel.

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