Formability and Correlation between Formability Indices of Al-0.9Mg-1.0Si-0.7Cu-0.6Mn Alloy for Automotive Body Sheets

2010 ◽  
Vol 638-642 ◽  
pp. 356-361 ◽  
Author(s):  
Ni Tian ◽  
Gang Zhao ◽  
Liang Zuo ◽  
Chun Ming Liu

The texture, the formability and the correlation between formability indices of Al-0.9Mg- 1.0Si-0.7Cu-0.6Mn alloy for automotive body sheets subjected to solid solution, T4, annealing treatment and artificial aging at 443k for different time were investigated by orientation distribution functions(ODF) analysis, tensile and cupping test, FLD measurement and regression analysis method. The results showed that the textures of cold rolled alloy sheets consist mainly of copper and brass orientations, which are transformed into the texture mainly containing {001}<310> orientation after recrystallization, and aging treatment has little influence on the recrystallization texture. The formability of alloy sheets subjected to solid solution, T4 and annealing treatment is similar, however, the formability was observably deteriorated after aging at 443k. The correlation between uniform elongation δu and FLD0 is the most remarkable in all the given formability indices, the correlation between strain-hardening exponent n and the FLD0 take second place, while there is no correlation between plastic strain ratio r and FLD0. The correlation between reduction of area ψ and cupping value IE is distinct, while ψ and IE have little correlation with FLD0.

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 81
Author(s):  
Zhengwei Gu ◽  
Gang Wang ◽  
Ge Yu

The fracture of a flat-surface straight-edge hemmed component of aluminum alloy sheets was investigated in this study. The specimen was made of 1 mm thick 6014-T4. Natural aging characteristics of 6014-T4 were studied via uniaxial tensile tests. The results show that the yield stress and ultimate tensile strength increased while the uniform elongation, strain hardening exponent, and plastic strain ratio decreased during the natural aging period, which worsened the formability. The sheet was biaxially stretched to obtain a pre-strain before the flanging and hemming operation. The influence of the flanging radius on the fracture was evaluated using experimental and numerical methods, and the optimum values were obtained. The comparison between the roller hemming and die hemming process proved that the former tends to produce better formability.


2011 ◽  
Vol 399-401 ◽  
pp. 148-151
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao

Hot rolled 260MPa grade high strength Nb-IF steel sheet was used to study the effect of coiling temperature and cold reduction ratio on the microstructures and mechanical properties. The experimental results showed that the recrystallization has finished. Under 650°Ccoiling temperature and 75% cold reduction ratio, and under 600°C or 700°C coiling temperature and 65% cold reduction ratio, the plastic strain ratio r value and the strain hardening exponent n value were reached the maximum, and respectively, the r value was approximate 1.8, the n value was approximate 0.26. That obtains optimally match of high strength and punching property.


2015 ◽  
Vol 817 ◽  
pp. 150-157
Author(s):  
Peng Cheng Ma ◽  
Di Zhang ◽  
Lin Zhong Zhuang ◽  
Ji Shan Zhang

Al-Mg alloys developed for auto body sheets with different Cu contents were fabricated in the laboratory scale. The effects of Cu content on the microstructures, formability and Portevin–Le Chatelier(PLC) effect of the alloys were investigated by polarizied optical microscopy and room temperature tensile testing. It has been found that with increasing Cu content, there was little change of the strain hardening exponent, but the plastic strain ratio and limiting drawing ratio increased firstly and then decreased. A quantitative statistical analysis of the characteristics of the PLC effect was made, including the stress drop and the reloading time, which follow a common linear relationship with plastic strain, and the increase rate of stress drop and reloading time was bigger with more Cu content. A detailed discussion of the corresponding mechanism of Cu and Cu-containing precipitates on the dynamic strain aging(DSA) was made.


2014 ◽  
Vol 886 ◽  
pp. 3-6
Author(s):  
Zu Jian Yu ◽  
Jian Hui Li ◽  
Yan Yang

Tensile tests and a cold deep drawing process were developed at room temperature to estimate the stamping formability of AZ31B magnesium alloy sheet. The results show that AZ31B magnesium alloy sheet has poor formability at room temperature with the total elongation of ~ 20%, the yield ratio is about 0.6 and the strain-hardening exponent is 0.18, while the plastic strain ratio is 1.58, and the earing ratio is-0.55.Thus, AZ31B magnesium alloy sheet can not suffer server plastic deformation. It was found that comparatively shallow magnesium alloy cups were satisfactorily formed at room temperature without heating when the punch fillet radius 6mm and the die fillet radius10mm with a 1mm thickness sheet with limit drawing ratio of 1.25.


1993 ◽  
Vol 21 (2-3) ◽  
pp. 93-108 ◽  
Author(s):  
J. J. Fundenberger ◽  
M. J. Philippe ◽  
C. Esling ◽  
P. Lequeu ◽  
B. Chenal

In order to point out the influence of the crystallographic texture on the formability of 2 aluminium alloys, the orientation distribution function (ODF) will be carried out using the series expansion method. Combining the ODF with a Taylor plastic deformation model we are able to calculate the yield loci and to predict the plastic strain ratio which is of high interest in the formability.


2011 ◽  
Vol 117-119 ◽  
pp. 1792-1797
Author(s):  
Min Li Wang ◽  
Li Xiao ◽  
Zhi Wang Zheng

Hot rolled added phosphorus high strength IF steel was used to study the effect of cold reduction ratio and annealing temperature on the microstructures and mechanical properties of experimental steel. The experimental results showed that the recrystallization has finished under 840°C to 880°C annealing temperature followed 65% to 75% cold reduction ratio. Under 600°C coiling temperature, 840°C annealing temperature and 65% to 75% cold reduction ratio, the yield strength, tensile strength ,elongation percentage, yield point elongation, the plastic strain ratio and strain hardening exponent were approximate 240MPa, 410MPa, 36.0%, 1.6%, 0.26 and 1.9. Under 650°C coiling temperature, 860°C annealing temperature and 65% to 75% cold reduction ratio, and that were approximate 240MPa, 415MPa, 35.0%, 2.0%, 0.24 and 1.9. Under 700°C coiling temperature, 880°C annealing temperature and 65% cold reduction ratio, and that were approximate 190MPa, 380MPa, 35.0%, 0.8%, 0.26 and 2.0. Therefore, the suggested the optimal coiling temperature6 is 600°C, cold reduction ratio is 65% to 75%, annealing temperature is 840 °C, and it obtains optimally match of high strength and punching property.


2011 ◽  
Vol 415-417 ◽  
pp. 883-888
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao

Hot rolled high strength Ti-Nb-IF steel sheet was used to study the effect of cold reduction ratio on the microstructures, mechanical properties and textures of experimental steel. The experimental results showed that the recrystallization has finished under different cold reduction ratio. The yield strength, tensile strength, elongation, the plastic strain ratio and strain hardening exponent were approximate 242MPa, 408MPa, 39.5%, 1.8, 0.26. With the cold reduction ratio increase, the textures strength increase, and the α textures have a trend with {111} texture. Therefore, the suggested the optimal cold reduction ratio is 75%, and it obtains optimally match of high strength and punching property.


Author(s):  
Shabbir Memon ◽  
Obaidur Rahman Mohammed ◽  
D. V. Suresh Koppisetty ◽  
Hamid M. Lankarani

Abstract As Pipelines are subjected to bursting failure, the prediction of the burst capacities of corroded pipelines is of significant relevance to the pipeline industry. The Single mode deformation processes, most commonly used in laboratory evaluations like tensile test, may not realistically predict formability performance. Therefore, limit strains tests that use multiple deformation stages would better simulate actual material performance hence bulge test is widely used in pipeline industry for analyzing formability. The tube bulge test is an advanced testing material in which the tube is placed in a die cavity and is sealed from both the ends, the water is injected from the hole inside the sealing punch and hydraulic pressure is increased and the tube gets deformed at the center. The objective of this work is to utilize Taguchi coupled finite element computational methodology to determine the optimum material parameters to attain better formability without necking-splitting failure. To evaluate the dependence of the slope of the forming limit diagram on the material parameters, the simulation under various combinations of strain-hardening exponent (n), plastic strain ratio (r) and thickness of tube (t) is carried out and using thickness gradient criterion, the occurrence of necking i. e. forming limit strains during tube bulging is examined. By observing the optimum condition obtained for maximum plain strain it is concluded that higher the n, r and t more the limit strains will be. It is also observed that among n, r and t, n is the most prominent factor contributing on limit strains followed by r and t. The verification of optimum process parameters obtained through Taguchi technique is carried out using additive model and it is found that the observed value is well in agreement with the predicted value, the extra validation simulation is carried out to validate the Taguchi results.


2018 ◽  
Vol 941 ◽  
pp. 1077-1082
Author(s):  
Li Zhen Yan ◽  
Yong An Zhang ◽  
Bai Qing Xiong ◽  
Zhi Hui Li ◽  
Xi Wu Li ◽  
...  

Intermediate annealing on anisotropy and mechanical properties of an Al-0.78Mg-0.90Si-0.65Zn-0.16Cu (wt. %) alloy was investigated by tensile test, optical microscope (OM) and electron back-scattered diffraction (EBSD). The results indicated that alloy sheet displayed various microstructure after without intermediate annealing, intermediate annealing treatment at 350°C for 2 h, 450°C for 2 h and 500°C for 5 min. Compared with the alloy without intermediate annealing, the alloy exhibited equiaxed grain with 35.0µm after annealing at 500°C for 5 min, grain orientation of the alloy was distributed randomly, and plastic strain ratio value of 45° direction was more than 0.6. The anisotropy of the sheet was significantly reduced. Annealing at 500°C for 5 min was suitable for the production process of automobile body sheets.


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