scholarly journals Grain Coarsening and Texture Evolution of Pre-Stretched 2219 Aluminum Alloy Sheets during Subsequent Solution Treatment

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 530 ◽  
Author(s):  
Lihui An ◽  
Jiguang Li ◽  
Shijian Yuan
Keyword(s):  
Aluminum Alloy ◽  
Grain Growth ◽  
Texture Evolution ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Stretch Forming ◽  
Forming Process ◽  
Deformation Degree ◽  
Grain Structures ◽  
2219 Aluminum Alloy

During the two-pass stretch forming process for manufacturing of thin-walled aluminum alloy sheet components, abnormal grain growth may happen if an improper pre-deformation degree was conducted before solution heat treatment, which is negative to the performance and surface quality of the final components. In order to overcome this problem, the effect of pre-stretching deformation was investigated on the change of grain structures of 2219 aluminum alloy sheets. The 2219 aluminum alloy sheets were pre-stretched with various deformation degrees, and then were heated to 540 °C for about 50 min for solution treatment. The grain structures before and after solution treatment were characterized using an optical microscope (OM) and electron back scattering diffraction (EBSD). Results show that the grains grew up gradually during the solution treatment with an increase of pre-stretching. The critical pre-stretching degree is about 3%. Once the pre-deformation exceeds 3%, the grain growth is significant, especially when it reaches 5%. Moreover, the pre-stretching has little influence on the orientation distribution. Some near a copper texture {112}<111> were generated as the pre-stretching degree was increased to 5%. All the results suggest that the pre-stretching before solution treatment cannot be larger than 3% in the two-pass stretch forming of a 2219 aluminum sheet.

scholarly journals Texture Evolution and Control of 2524 Aluminum Alloy and Its Effect on Fatigue Crack Propagation Behavior

2021 ◽  
Vol 11 (12) ◽  
pp. 5550
Author(s):  
Yuqiang Chen ◽  
Chuang Xiong ◽  
Wenhui Liu ◽  
Suping Pan ◽  
Yufeng Song ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Cold Rolling ◽  
Texture Evolution ◽  
Cold Deformation ◽  
Solution Treatment ◽  
Second Phase ◽  
Fatigue Crack Growth Resistance ◽  
Volume Fractions

The influences of cold rolling and subsequent heat treatment on the microstructure evolution of 2524 alloy were investigated using an orientation distribution function (ODF) and electron back-scattered diffraction (EBSD). A preparation method of 2524-T3 aluminum alloy with a strong Brass texture was developed, and its effect on the fatigue properties of the alloy was investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that with the increase in cold rolling deformation from 0% to 80%, the volume fractions of Brass, copper, and S textures in the 2524-T3 alloy also increase, especially in the case of Brass and S textures. However, the volume fractions of cube and Goss textures are reduced significantly, especially for cube textures, which are decreased by 57.4%. Reducing coarse second-phase particles (CSPs) is conducive to the formation of a strong deformation texture during cold rolling. A 10% deformation at each rolling pass, followed by a step annealing, helps the preservation of a Brass texture even after solution treatment at 500 °C for 0.5 h, while a large cold deformation followed by high-temperature annealing helps the formation of a strong cube texture. The Brass texture can enhance the strength while decreasing the fatigue crack growth resistance of this alloy.

Coefficient of Friction for Aluminum Alloy Sheet in Contact with Polyurethane Rubber

2010 ◽  
Vol 26-28 ◽  
pp. 320-325 ◽  
Author(s):  
Li Li Wang ◽  
Dong Sheng Li ◽  
Xiao Qiang Li ◽  
Liang Wang ◽  
Wei Jun Yang
Keyword(s):  
Aluminum Alloy ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Orthogonal Experimental Design ◽  
Sliding Velocity ◽  
Stretch Forming ◽  
Forming Process ◽  
Alloy Material ◽  
The Coefficient Of Friction ◽  
The Impact

Stretch forming process of aircraft skin over reconfigurable compliant tooling is a new technology in skin manufacturing. During this process, the coefficient of friction is important for modeling accurately the process of stretch forming. The objective of this research is to measure the coefficient of friction for aluminum alloy in contact with polyurethane rubber in reciprocal sliding. An orthogonal experimental design was used to reveal the impact of four factors on the coefficient of friction, including lubrication, normal load, aluminum alloy material and sliding velocity. It is shown that lubrication is a major factor, sliding velocity is a minor factor. The influence of normal pressure is less than sliding velocity and the influence of aluminum alloy material is not very obvious. Finally, based on the experiment results, the selections of lubricant and stretching velocity are discussed in order to improve the process of stretch forming.

scholarly journals Effects of Deformation Parameters on Microstructural Evolution of 2219 Aluminum Alloy during Intermediate Thermo-Mechanical Treatment Process

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1496 ◽  
Author(s):  
Lei Liu ◽  
Yunxin Wu ◽  
Hai Gong
Keyword(s):  
Aluminum Alloy ◽  
Strain Rate ◽  
Mechanical Treatment ◽  
Treatment Process ◽  
Solution Treatment ◽  
Deformation Parameters ◽  
Solid Solution Treatment ◽  
2219 Aluminum Alloy ◽  
Thermo Mechanical Treatment ◽  
Storage Energy

To explore the effective way of grain refinement for 2219 aluminum alloy, the approach of ‘thermal compression tests + solid solution treatment experiments’ was applied to simulate the process of intermediate thermo-mechanical treatment. The effects of deformation parameters (i.e., temperature, strain, and strain rate) on microstructural evolution were also studied. The results show that the main softening mechanism of 2219 aluminum alloy during warm deformation process is dynamic recovery, during which the distribution of CuAl2 phase changes and the substructure content increases. Moreover, the storage energy is found to be decreased with the increase in temperature and/or the decrease in strain rate. In addition, complete static recrystallization occurs and substructures almost disappear during the solid solution treatment process. The average grain size obtained decreases with the decrease in deforming temperature, the increase in strain rate, and/or the increase in strain. The grain refinement mechanism is related to the amount of storage energy and the distribution of precipitated particles in the whole process of intermediate thermal-mechanical treatment. The previously existing dispersed fine precipitates are all redissolved into the matrix, however, the remaining precipitates exist mainly by the form of polymerization.

scholarly journals Influence of Hot Deformation on the Precipitation Hardening of High-Strength Aluminum AA7075 during Thermo-Mechanical Processing

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 681
Author(s):  
Emad Scharifi ◽  
Daria Shoshmina ◽  
Stefan Biegler ◽  
Ursula Weidig ◽  
Kurt Steinhoff
Keyword(s):  
Hot Deformation ◽  
Fine Particles ◽  
Solution Treatment ◽  
High Strength ◽  
Dislocation Motion ◽  
Forming Process ◽  
Deformation Degree ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Material Hardness

The aim of this work was to investigate the effect of hot deformation on the aging behavior of precipitation-hardenable aluminum alloy AA7075 within a novel thermo-mechanical forming process, in order to gain insight into its precipitation kinetics. For this purpose, the material was formed at 420 °C after undergoing solution treatment to different strain levels ranging from 2% to 10% to obtain different dislocation densities. After undergoing hot deformation, aging at 120 °C with different parameters was carried out to improve the material hardness. The resulting material properties and microstructure evolution were characterized afterward using hardness measurements and a transmission electron microscope (TEM). TEM investigations revealed the formation of very fine particles for the material formed at 2%, as well as at 10%, of formed material, which act as effective barriers to dislocation motion. It was found that the response of artificial aging on the deformation degree in hot forming was less than expected due to the thermally activated mechanisms, leading to a decrease in dislocation density. Therefore, a dramatic increase in material hardness with the increase in hot deformation was not observed.

Static Recrystallization and Texture Evolution of 316L Stainless Steel Fibers

2014 ◽  
Vol 1052 ◽  
pp. 45-50 ◽  
Author(s):  
Hai Ou Yu ◽  
Yan Wang ◽  
Yong Liu ◽  
Hui Ping Tang
Keyword(s):  
Stainless Steel ◽  
Grain Growth ◽  
316L Stainless Steel ◽  
Texture Evolution ◽  
Optical Microscope ◽  
Steel Fibers ◽  
X Ray ◽  
Average Grain Size ◽  
Before And After ◽  
Growth Equations

By isothermal annealing tests, the recrystallization and grain growth behaviors of 316L stainless steel fibers with a diameter of 8 μm were investigated using the optical microscope (OM), scanning electron microscope (SEM) and X-ray texture analysis methods. The average grain size of the fibers with a diameter of 8 μm annealed at different conditions was quantitatively measured. The grain growth equations of the fibers were constructed, and the activation energies for grain growth of the fibers were also determined. Meanwhile, efforts have been paid on analyzing the texture evolution of 316L stainless steel fibers before and after annealing.

Optimization of Multi-Point Forming for Aluminum Alloy Profile

2021 ◽  
Vol 1033 ◽  
pp. 13-17
Author(s):  
Jin Yang ◽  
Wen Zhi Fu ◽  
Ming Zhe Li ◽  
Yan Wen Yang
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Finite Element Simulation ◽  
Stretch Forming ◽  
Forming Process ◽  
Element Simulation

According to the profile processing, two forming processes are proposed, i.e., multi-point stamping forming and multi-point stretch forming. Through the finite element simulation, two forming processes are simulated and compared. The analysis results show that the longitudinal springback and transverse forming error of parts by multi-point stretch forming are smaller than those by multi-point stamping forming, so the multi-point stretch forming process is suitable for processing this kind of aluminum alloy profile.

scholarly journals Investigation on Compressive Formability and Microstructure Evolution of 6082-T6 Aluminum Alloy

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 469
Author(s):  
Zhouli Xu ◽  
Huijuan Ma ◽  
Ning Zhao ◽  
Zhili Hu
Keyword(s):  
Aluminum Alloy ◽  
Treatment Time ◽  
Heating Temperature ◽  
Solution Treatment ◽  
Heating Time ◽  
Strengthening Effect ◽  
Forming Process ◽  
Production Time ◽  
Precipitated Phase ◽  
First Choice

The 6xxx aluminum alloy is the first choice for automotive lightweight forgings due to its excellent performance, high strength and low weight. The production time of current aluminum alloy forging generally exceeds 10 h. To reduce the production time of traditional aluminum alloy forgings, 6082-T6 aluminum alloy is used in the forming process. The effects of different heating temperatures (200 °C, 300 °C, and 400 °C) and deformation degrees (30%, 50%, and 70%) on the deformability and properties of 6082-T6 billets have been investigated. The results show that when the heating temperature is higher than 300 °C, the compressive deformation resistance obviously decreases with increasing strength. With compression at 200 °C and 70% deformation with short heating time, the strength of the sample is close to the T6 (solution treatment and artificial aging) state. A large number of dislocations and subgrains were introduced due to the compression deformation, and their amounts decreased as the heating temperature increased. The size of the precipitated phase β′′ slightly grows under a heating temperature of 200 °C. However, when the heating temperature is higher than 300 °C, the precipitated phase gradually changes from β′′, which is optimal for the strengthening effect, to β′ and β, which offer weaker strengthening. Therefore, under a lower heating temperature of 200 °C for 5 min, a large number of dislocations are introduced with the β′′ precipitated phase, leading to higher strength with less heat treatment time.

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