Characterizing the Effect of Processing Parameters on Temperature Distribution of 7075 Aluminum Alloy Slurry Prepared by Enthalpy Control Process

2022 ◽  
Vol 327 ◽  
pp. 263-271
Author(s):  
Gan Li ◽  
Jin Kang Peng ◽  
En Jie Dong ◽  
Juan Chen ◽  
Hong Xing Lu ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Temperature Difference ◽  
Initial Temperature ◽  
Control Process ◽  
Processing Parameters ◽  
Heating Time ◽  
7075 Aluminum Alloy ◽  
Semi Solid ◽  
7075 Alloy ◽  
Slurry Preparation

There is a strong demand for high-strength aluminum alloys such as 7075 aluminum alloy to be applied for rheocasting industry. The overriding challenge for the application of 7075 alloy is that its solid fraction is very sensitive to the variation of temperature in the range of 40% ~ 50% solid fraction, which inevitably narrows down the processing window of slurry preparation for rheocasting process. Therefore, in this work, a novel method to prepare semi-solid slurry of the 7075 alloy, so called Enthalpy Control Process (ECP), has been developed to grapple with this issue. In the method, a medium-frequency electromagnetic field was applied on the outside of slurry preparation crucible to reduce the temperature difference throughout the slurry. The effect of processing parameters, including heating power, heating time, the initial temperature of crucible and melt weight, on the temperature field of the semi-solid slurry was investigated. The results exhibited that although the all the processing parameters had a great influence on the average temperature of the slurry, heating time was the main factor affecting the maximum temperature difference of the slurry. The optimum processing parameters during ECP were found to be heating power of 7.5 KW, the initial temperature of crucible of 30 °C ~ 200 °C and melt weight of 2 kg.

Numerical Simulation of Slurry Making Process of 7075 Aluminum Alloy under Electromagnetic Field in Rheocasting Process

2019 ◽  
Vol 285 ◽  
pp. 373-379 ◽  
Author(s):  
Gan Li ◽  
Hong Xing Lu ◽  
Xiao Gang Hu ◽  
Qiang Zhu
Keyword(s):  
Aluminum Alloy ◽  
Solid Fraction ◽  
Temperature Difference ◽  
Lower Cost ◽  
Simulation Method ◽  
7075 Aluminum Alloy ◽  
Compensation Process ◽  
The Common ◽  
Semi Solid ◽  
Slurry Preparation

Rheocasting processes have several technological advantages, such as shorter processing and lower cost than thixocasting processed, while better product quality than conventional die casting. At present, the common alloys used in rheocasting processes are mainly Al-Si alloys which have limited strength. There is a strong demand for higher strength aluminum alloys in industries, for instance the 7075 aluminum alloy. However, the solid fraction of the 7075 aluminum alloy varies significantly with the temperature change in the medium solid fraction range from 0.4 to 0.6, which poses a great challenge to the slurry preparation. The enthalpy compensation process, in which the core was electromagnetic heating in the outside of the metallic crucible containing aluminum alloy melt, has been proposed to reduce the temperature difference within semi-solid slurry in this work. This study used simulation method to analyze the effects of key process parameters on the temperature difference within the 7075 aluminum alloy slurry. The simulation results indicated that semi-solid slurry with medium solid fraction may be obtained and temperature difference may be reduced to less than 4°C.

Preparation of Large-Diameter Semi-Solid 7075 Aluminum Alloy Billets

2008 ◽  
Vol 141-143 ◽  
pp. 361-365 ◽  
Author(s):  
Wei Wei Wang ◽  
Jian Li Song ◽  
Shou Jing Luo
Keyword(s):  
Aluminum Alloy ◽  
Heating Temperature ◽  
Large Diameter ◽  
Processing Parameters ◽  
7075 Aluminum Alloy ◽  
Dimensional Precision ◽  
Average Grain Size ◽  
Wide Range ◽  
Fine Microstructure ◽  
Semi Solid

Preparation of semi-solid microstructure of 7075 aluminum alloy industrial extrusion billets was studied in this paper. A new semi-solid microstructure preparation process is proposed. In the treatment, melting-stirring and predeformation of the alloy billets are not required. An ideal microstructure and higher dimensional precision of the billet can be obtained only with a direct heating and insulation method. The influences of different heating temperatures and insulation time on the microstructure evolution were studied with orthogonal testing methods. The obtained microstructure was observed and analyzed by optical microscopy, and the formation mechanism of the semi-solid microstructure is further discussed. The results indicate that a fine microstructure can be obtained with the proposed process and the processing parameters can be controlled over a wide range. Also, the grain microstructure obtained by the present process is better than that of the SIMA. For 7075 aluminum alloy billets, perfect fine equiaxial grains can be obtained under a heating temperature of 620°C and a holding time of about 25 minutes. The average grain size is around 80μm.

Effect of Heat Treatment on Mechanical Properties of ECAPed 7075 Aluminum Alloy

2013 ◽  
Vol 829 ◽  
pp. 62-66 ◽  
Author(s):  
Alireza Fallahi ◽  
Hossein Hosseini-Toudeshky ◽  
Seyed Mahmoud Ghalehbandi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Thermal Stability ◽  
Aluminum Alloy ◽  
Solution Treatment ◽  
7075 Aluminum Alloy ◽  
Ecap Processing ◽  
Good Thermal Stability ◽  
7075 Alloy

It is the objective of this study to investigate the effect of ECAP processing and heat treatment on the mechanical properties of the UFG 7075 alloy. Also the effect of post ECAP heat treatment is investigated. The alloy is processed by ECAP after annealing as well as solution treatment to produce an UFG structure. Furthermore mechanical properties and their variations during annealing and aging are investigated. The hardness of the pre-ECAP annealed and the pre-ECAP solutionised 7075 aluminum alloy has increased significantly compared with that of the CG sample. Also hardness of ECAPed specimen has not experienced significant changes in post-ECAP heat treatment and indicated that the alloy had approximately good thermal stability.

Experimental Research on Surface Roughness of Ultrasonic Assisted Grinding on 7075 Aluminum Alloy

2021 ◽  
Vol 1047 ◽  
pp. 62-67
Author(s):  
Shen Wang ◽  
Le Tong ◽  
Guang Jun Chen ◽  
Mao Xun Wang ◽  
Bin Dai ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Processing Parameters ◽  
7075 Aluminum Alloy ◽  
Machined Surface ◽  
Ultrasonic Assisted Grinding ◽  
Great Performance ◽  
Ultrasonic Assisted ◽  
Conventional Grinding ◽  
Micro Morphology

7075 aluminum alloy is widely used due to its great performance, especially in aerospace area. In this paper, ultrasonic-assisted grinding technology is used to process 7075 aluminum alloy. The data is obtained through experiments, and the surface roughness and morphology of ultrasonic assisted grinding and conventional grinding under different spindle speeds, feed rates, and amplitudes are analyzed. Research has found that the increase in spindle speed and amplitude will improve the quality of the machined surface and reduce the surface roughness by 82.1% and 36%. However, with the increase of feed rate, the surface quality decreased significantly, and the surface roughness increased by 55.6%. The surface micro-morphology of the machined workpiece is observed, and the effects of different processing parameters on the surface micro-morphology are obtained.

scholarly journals Soldering of 7075 Aluminum Alloy Using Ni-P and Cu-Cr Electrodeposited Interlayers

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4100
Author(s):  
Zbigniew Mirski ◽  
Ireneusz Ciepacz ◽  
Tomasz Wojdat
Keyword(s):  
Electron Microscopy ◽  
Shear Strength ◽  
Aluminum Alloy ◽  
Light And Electron Microscopy ◽  
7075 Aluminum Alloy ◽  
7075 Alloy ◽  
Aluminum Alloy 7075 ◽  
Soldered Joint ◽  
Measured Hardness ◽  
Made In

Direct soldering of the aluminum alloy 7075 is very difficult or even impossible. In order to make it possible, galvanic coatings and the procedures for their application on alloy surfaces were developed. The paper presents structures and mechanical properties of soldered joints of the 7075 alloy, made in indirect way with use of electrolytically deposited Ni-P and Cu-Cr coatings. Application of the newly developed Ni-P and Cu-Cr coatings on base surfaces of the 7075 alloy is described. The results of wettability examination of the S-Sn97Cu3 solder in the droplet test and by spreading on the coatings applied on the 7075 substrates are presented. The wettability angle of both coatings was lower than 30°. The results of metallographic examinations with use of light and electron microscopy are presented. It was shown that adhesion of metallic coatings to the aluminum alloy is good, exceeding shear strength of the S-Sn97Cu3 solder. Shear strength of soldered joint was equal to 35 ± 3 MPa. Measured hardness of the Ni-P interlayer reached high value of 471 HV 0.025.

Microstructure Control and Mechanical Properties of 7075 Aluminum Alloy by Means of Multi-Pass Friction Stir Processing

2011 ◽  
Vol 409 ◽  
pp. 281-286
Author(s):  
Yutaka Matsuda ◽  
Goroh Itoh ◽  
Yoshinobu Motohashi
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Processing ◽  
Microstructural Characterization ◽  
Tensile Tests ◽  
7075 Aluminum Alloy ◽  
Tensile Direction ◽  
Friction Stir ◽  
Electron Microscopies ◽  
7075 Alloy

Friction stir processing (FSP) is a method for controlling the microstructure that has been proposed by applying friction stir welding, FSW. In this study, microstructure and mechanical properties of a 7075 aluminum alloy subjected to multi-pass FSP, MP-FSP, are assessed to obtain fundamental knowledge for improving the plasticity of aluminum alloys. The MP-FSP has been applied to 7075 alloy plates with T6 and O tempers, and microstructural characterization has been made by means of optical and scanning electron microscopies together with EDX and EBSD analyses, while mechanical properties were measured by means of micro hardness and tensile tests at room and high temperatures. From microstructural observation, a new zone, PBZ, has been discovered between stir zones, SZs. The PBZ is composed of two types of (fine and coarse) grains, where the coarse grain contains many sub-grains. Hardness in PBZ is intermediate between that in BM and SZ both in T6 and O specimens; hardness generally decreases and increases in T6 and O specimens, respectively, by MP-FSP. In accord to the hardness change, strength at room temperature is decreased by MP-FSP in T6 specimen, and increased in O specimen. Elongation at 773K is increased both in T6 and O specimens because of superplastic deformation. However, local elongation is smaller in PBZ than in SZ, which can be attributed to the microstructural change by the deformation: grain shape remains equiaxed in SZ while it becomes elongated in the tensile direction in PBZ.

Creep of Rheocast 7075 Aluminum Alloy at 300 °C

2013 ◽  
Vol 372 ◽  
pp. 288-291 ◽  
Author(s):  
Saravut Thongkam ◽  
Sirikul Wisutmethangoon ◽  
Jessada Wannasin ◽  
Suchart Chantaramanee ◽  
Thawatchai Plookphol
Keyword(s):  
Aluminum Alloy ◽  
Creep Rate ◽  
Creep Deformation ◽  
Minimum Creep Rate ◽  
7075 Aluminum Alloy ◽  
Stress Range ◽  
Dislocation Glide ◽  
Semi Solid ◽  
Power Law Creep ◽  
Rupture Strain

Creep of rheocast 7075-T6 aluminum alloy produced by the Gas Induced Semi-Solid (GISS) process was investigated at temperature of 300 °C and stress range of 20-70 MPa and compared to that of wrought 7075-T651 aluminum alloy. The rheocast 7075-T6 alloy exhibited lower minimum creep rate and longer rupture time than the wrought 7075-T651 alloy. The total rupture strain of the rheocast alloy was shorter than that of the wrought one. According to the power law creep, the stress exponents, n of the rheocast 7075-T6 and the wrought 7075-T651 alloys were 5.9 and 7.9 respectively. Based on the determined n values, the creep deformation of both alloys was possibly controlled by the dislocation glide and climb-controlled mechanism.

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