A Study on Micro Bending of Thin Stainless Steel Sheets
Date Issued
2009
Date
2009
Author(s)
Shih, Wen-Chieh
Abstract
With the ongoing miniaturization in manufacture, there is a growing demand on micro products that have many advantages, such as lower cost, efficient mass production, higher strength, etc. Among the micro-productions, the micro-bending of thin stainless steel sheets has obtained a variety of applications in the IT industry. Though the macro-bending process has been well-developed, the design concepts may not be directly applied to the micro-bending due to the size effect occurred in the micro-forming processes. In the present study, the micro-bending of 301 stainless steel sheets with different thicknesses was studied. A thorough literature survey regarding the macro-bending technology and the current development status of micro-bending was made first. In order to obtain the material properties of the miniaturized 301 sheets, the tensile tests were conducted. The bending tests were also performed to examine the effects of sheet size and grain size on the micro-bending processes. The size effects occurred in both the tensile tests and the bending tests were observed. The effects of the process parameters, such as tooling corner radii and friction condition, on the micro-bending of thin 301 sheets were studied as well in the present study by both the experimental approaches and the finite element analyses. The stress distributions calculated from the finite element simulations explained the deformation mechanics of the springback occurred in the micro-bending of thin steel sheets. And it is found that both the sheet size and the grain size, in addition to the process parameters, have significant effects on the springback phenomenon occurred in the micro-bending of 301 stainless steel sheets. The results obtained in the present study could be valuable references to the future researches on the micro-bending of other kinds of thin metal sheets.
Subjects
301 stainless steel
micro-bending
size effect
springback
grain size
process parameters
finite element analysis
experiment verification
Type
thesis