Optimization of Crystallographic Texture for Sheet-forming Applications Using Taylor-based Models
- PDF / 4,095,562 Bytes
- 18 Pages / 593.972 x 792 pts Page_size
- 7 Downloads / 143 Views
CTION
SHEET metal forming is one of the main manufacturing processes in industry worldwide. Deep drawing of metal sheets is an essential operation in the production of vehicles, many construction elements and electronic devices, and industrial and home appliances. It is therefore essential to know how the properties of a metal sheet affect its capacity to be deformed and the quality of the final products. Indeed, the scientific community has extensively studied all kinds of problems related with sheet metal forming,[1] making use of the most advanced techniques in the fields of finite element modeling[2] and crystallographic texture analysis[3] as they have become available.
JESU´S GALA´N-LO´PEZ is with the Materials Innovation Institute M2i, Van der Burghweg 1, 2628 CS, Delft, The Netherlands and also with the Materials Science and Engineering Department, Faculty 3mE, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The Netherlands. Contact e-mail: [email protected] LEO A.I. KESTENS is with the Materials Science and Engineering Department, Faculty 3mE, Delft University of Technology and also with the Department of Materials Science and Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 903, Zwijnaarde, 9052, Ghent, Belgium. Manuscript submitted April 12, 2018.
METALLURGICAL AND MATERIALS TRANSACTIONS A
To obtain the best results in a deep-drawing process, a metal sheet must deform with a specific anisotropic behavior. An ideal sheet would be one that can accommodate any arbitrary shape without experiencing any variation in thickness. More realistically, metal sheets used in industrial processes are selected such that the strain in the direction normal to the sheet plane takes a value as low and uniform as possible. A. Quantitative Indicators of Formability Several magnitudes have been proposed to quantify the formability of metal sheets.[4] The Lankford coefficients, or r values,[5] and the contraction ratios, or q values, defined by Bunge,[6] are both widely used. Although these parameters are not an intrinsic material property, but affected by external factors such as specimen geometry and applied strain,[7,8] it is possible to use r and q values to compare different materials as long as these factors are carefully controlled. The r and q values are correlated, but r values present some inconvenience when used for quantitative data analysis[9]—in particular for optimization problems—because of the possibility of infinite values. For convenience, only q values will be used in the following. Optimal formability properties will be obtained when the q value in every direction parallel to the sheet plane is equal to one. In practice, the aim is that the q values become as high as possible, while being the same for every direction. This condition will be evaluated using
the arithmetic mean and standard deviation of all the q values between 0 and 90 degrees at 15-degree intervals*. *The more traditional q and Dq indicators, calculated on the basis of the q0 , q45 and q90 value
Data Loading...
