scholarly journals Deformation Characteristics and Microstructure Analysis of Aluminum Alloy Component with Complex Shape by Cold Orbital Forming

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 808
Author(s):  
Wei Feng ◽  
Chaoyi Jin ◽  
Jiadong Deng ◽  
Wuhao Zhuang

This work aimed to study the deformation characteristics and microstructure of AA6063 aluminum alloy component with complex shape manufactured by cold orbital forming processing. The material flowing behavior was analyzed by Finite Element (FE) simulation and forming experiments were carried out using bar blank with different lengths. The microstructure of the boss zone cut from the formed samples was observed using scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD). FE simulation and experiment results both showed the aluminum base can be formed using cold orbital forming process. The distributions of the effective strain of the component with different blank lengths were almost the same, and the effective strain was bigger at the boss and the flash as the forming finished. The material flow is complex, especially in the boss, and the folding defect was observed at the root of the boss. The distribution of Mg2Si strengthening precipitate is more homogeneous in the matrix, has a different shape, and shows directivity at different position of boss zone. The grains are elongated, and the extent is different at different positions of the boss zone after cold orbital forming, and the crystal orientation discrepancy is smaller in the component main body and bigger in the boss zone. Subsequent forming process and blank optimization need to be further researched to improve forming quality.

2021 ◽  
Author(s):  
Shengqiang Liu ◽  
Jinping Liu ◽  
Hao Xu ◽  
Zhipeng Wang ◽  
Jinxia Shen ◽  
...  

Abstract Cold helical rolling (CHR) is one of the most effective ways to produce small-diameter steel balls. In this study, one kind of work hardening model was established and implemented into Simufact 15.0 to investigate the work hardening phenomenon in the cold forming process. Firstly, based on the helical rolling theory, a set of finite element (FE) simulations was developed. The influence of CHR parameters, including the starting height of convex rib, forming area length, and rolling inclination angle, on the forming process was studied via simulation. Furtherly, the CHR process experiments and FE simulation were carried out , the results showed that the FE simulation was in good agreement with the experimental results, and consistent with the predicted value of the theoretical calculation. Finally, the evolution of effective strain, effective stress, rolling force, work hardening and microstructure during the cold helical rolling of Φ 5.12 mm steel balls was investigated via FE. As result, the evolution trend of hardness was consistent with that of dislocation density, indicating that the model is credible. Besides, the microstructure of the steel ball at different positions further verified this.


2010 ◽  
Vol 654-656 ◽  
pp. 875-878
Author(s):  
Jin Gee Park ◽  
Nho Kwang Park ◽  
Young Suk Kim

Titanium alloy sheets have excellent specific strength and corrosion resistance as well as good performance at high temperature. Recently, titanium alloys are widely employed not only aerospace parts but also prosthetics and motorcycle. However, titanium and its alloys are difficult-to-form materials due to limited slip system and plastic anisotropy. Titanium alloy sheets were usually formed by slow forming or hot forming with heating die and specimen. In the sheet metal forming area, FE simulation technique to optimize forming process is widely used. To achieve high accuracy FE simulation results, identification of material properties and deformation characteristics such ad yield behaviors are very important. In this study, the yield locus of Ti-6Al-4V sheet was obtained at warm temperature. The experimental results are compared with the theoretical predictions. Also, the Forming Limit Curves (FLC) was achieved at warm temperature.


2021 ◽  
pp. 152808372098410
Author(s):  
Mehmet Korkmaz ◽  
Ayşe Okur ◽  
Ahmad Rashed Labanieh ◽  
François Boussu

Composite materials which are reinforced with 3D warp interlock fabrics have outstanding mechanical properties such as higher delamination resistance, ballistic damage resistance and impact damage tolerance by means of their improved structural properties. Textile reinforcements are exposed to large deformations in the production stage of composite materials which have complex shape. Although good formability properties of 3D warp interlock fabrics in forming process were already proven by recent studies, further information is needed to elucidate forming behaviours of multi-layer fabrics which is produced with high stiffness yarns like carbon. In this study, 3D warp interlock carbon fabrics were produced on a prototype weaving loom and the same carbon yarn was used in two fabric directions with equal number of yarn densities. Fabrics were differentiated with regard to the presence of stuffer warp yarn, weave pattern and parameters of binding warp yarn which are angle and depth. Therefore, the effect of fabric architecture on the mechanical and formability properties of 3D warp interlock carbon fabrics could be clarified. Three different breaking behaviours of fabrics were detected and they were correlated with crimp percentages of yarn groups. In addition, the bending and shear deformations were analysed in view of parameters of fabric architectures. Two distinct forming behaviours of fabrics were determined according to the distribution of deformation areas on fabrics. Moreover, the optimal structure was identified for forming process considering the fabric architecture.


Author(s):  
Xinghui Han ◽  
Qiu Jin ◽  
Lin Hua

This study aims at exploring the potentialities of cold orbital forming in forming complex sheet metal. Aiming at a complex mobile phone shell component of aluminum alloy, two technical schemes for cold orbital forming are first presented. Then, the optimized one, i.e., the more complex inner surface of mobile phone shell is arranged to be formed by the rocking punch with a complex motion, is determined by analyzing the nonuniform plastic deformation laws and punch filling behaviors. On the basis of the optimized technical scheme, the blank geometry in cold orbital forming of mobile phone shell is also optimized based on the forming status of the most difficult forming zone. The consistent finite element (FE) simulated and experimental results indicate that under the optimized technical scheme, not only the bosses in the mobile phone shell are fully formed but also the obtained flow lines are reasonable, which proves that the technical scheme presented in this study is feasible and cold orbital forming exhibits huge potentialities in forming complex sheet metal.


2012 ◽  
Vol 452-453 ◽  
pp. 81-85
Author(s):  
M.H. Chen ◽  
Y.Y. Cao ◽  
W. Chen ◽  
G.L. Chen

2020 ◽  
Vol 9 (3) ◽  
pp. 4706-4716
Author(s):  
Z.X. Li ◽  
M. Zhan ◽  
X.G. Fan ◽  
X.X. Wang ◽  
F. Ma

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1380
Author(s):  
Sofia Papadopoulou ◽  
Athina Kontopoulou ◽  
Evangelos Gavalas ◽  
Spyros Papaefthymiou

During forming, thickness reduction and thermal treatment affect the recrystallization and evolution of the crystallographic texture of metallic materials. The present study focuses on the consequences of rolling reduction of a widespread aluminum alloy with numerous automotive, marine and general-purpose applications, namely Al 5182. Emphasis is laid on the crystallographic texture and mechanical properties on both hot and cold-rolled semi-final products. In particular, a 2.8 mm-thick hot-rolled product was examined in the as-received condition, while two cold-rolled sheets, one 1.33 mm and the other 0.214 mm thick, both originating from the 2.8 mm material, were examined in both as-received and annealed (350 °C for 1 h) conditions. Electron back-scatter diffraction indicated the presence of a large percentage of random texture as well as a weak recrystallization texture for the hot-rolled product, whereas in the case of cold rolling the evolution of β-fiber texture was noted. In addition, tensile tests showed that both the anisotropy as well as the mechanical properties of the cold-rolled properties improved after annealing, being comparable to hot-rolled ones.


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