Evaluation of Different Influencing Factors in Dry Sheet Metal Forming with Vaporizing CO2 Used as Lubricant

2015 ◽  
Vol 794 ◽  
pp. 53-58 ◽  
Author(s):  
Markus Singer ◽  
Mathias Liewald

Lubricants in sheet metal forming have to meet increasing demands resulting from political aims and ecological requirements. For that reason, industry aspires the reduction of lubrication with the long term goal of replacing conventional mineral oil based lubricants entirely. Dry metal forming to a certain limit can be achieved by using liquid CO2 during the forming process. This lubricant vaporizes after deep drawing process and leaves a clean work piece that can be used in coating or joining processes without any subsequent cleaning. In this contribution, further development and resulting effects of numerous process parameters are evaluated and presented. Investigations of restraining forces in strip draw tests when lubricated with liquid CO2 include different tool parameters like drilling diameters (120 and 140 µm), different numbers of drillings (25 and 49) as well as different process parameters like surface pressure (2,5 and 6,5 MPa) or drawing speed (50 and 100 mm/s). Amount of restraining forces in this paper also are compared to two different conventional mineral oil based lubricants (Wisura AK 3080 and Wisura ZO 3368). The results presented in this contribution may provide a better understanding of tribological mechanisms emerging within this new lubrication system.

2011 ◽  
Vol 63-64 ◽  
pp. 3-7
Author(s):  
Yan Min Xie

This paper presents a methodology to effectively determine the optimal process parameters using finite element analysis (FEA) and design of experiments (DOE) based on Metamodels. The idea is to establish an approximation function relationship between quality objectives and process parameters to alleviate the expensive computational expense in the optimization iterations for the sheet metal forming process. This paper investigated the Kriging metamodel approach. In order to prove accuracy and efficiency of Kriging method, the nonlinear function as test functions is implemented. At the same time, the practical nonlinear engineering problems such as square drawing are also optimized successfully by proposed method. The results prove Kriging model is an effective method for nonlinear engineering problem in practice.


2005 ◽  
Vol 6-8 ◽  
pp. 465-470 ◽  
Author(s):  
Horst Meier ◽  
O. Dewald ◽  
Jian Zhang

This paper describes a new sheet metal forming process for the production of sheet metal components for limited-lot productions and prototypes. The kinematic based generation of the shape is implemented by means of a new forming machine comprising of two industrial robots. Compared to conventional sheet metal forming machines this newly developed sheet metal forming process offers a high geometrical form flexibility and also shows comparatively small deformation forces for high deformation degrees. The principle of the procedure is based on flexible shaping by means of a freely programmable path-synchronous movement of the two robots. The sheet metal components manufactured in first attempts are simple geometries like truncated pyramids and cones as well as spherical cups. Among other things the forming results could be improved by an adjustment of the movement strategy, a variation of individual process parameters and geometric modifications of the tools. Apart from a measurement of the form deviations of the sheet metal with a Coordinate Measurement Machine rasterised and deformed sheet metals were used for deformation analyses. In order to be able to use the potential of this process, a goal-oriented process design is as necessary as specific process knowledge. In order to achieve process stability and safety the essential process parameters and the process boundaries have to be determined.


Author(s):  
Brad Kinsey ◽  
Neil Krishnan

In order to realize the potential of sheet metal forming and take advantage of new process control capabilities, innovative modifications to the traditional sheet metal forming process must be developed. These modifications are particularly important with respect to Tailor Welded Blank (TWB) forming, which offers an excellent opportunity to reduce manufacturing costs, decrease part weight, and improve the quality of sheet metal stampings. However, tearing near the weld seam and wrinkling in the formed wall area and die addendum of the part often occurs when a traditional forming process is used to form a TWB. Research and industrial experience has shown that these forming concerns can be alleviated through advanced forming techniques, for example using a segmented die process or a non-uniform binder force. The difficulty then becomes determining the key process parameters associated with these forming methods. In this paper, a methodology is presented to effectively and easily determine both the location of a segmented die and a non-uniform binder force by evaluating nodal reaction forces provided from FEA simulations. Also, using FEA simulations to determine the process parameters for another advanced forming process, strain path control tooling, is discussed. The advanced forming processes presented in this paper and the use of FEA to determine key process parameters are critical components to the continued evolution of sheet metal forming processes.


2005 ◽  
Vol 6-8 ◽  
pp. 517-524 ◽  
Author(s):  
Hartmut Hoffmann ◽  
R. Hautmann ◽  
R. Petry

The manufacturing technique of driving is one of the oldest procedures for sheet metal forming and has been used in the ancient world for the production of copper pots and vases. This technique is still utilized for niche applications but today has lost its importance. The process of driving is almost completely carried out manually and thus is only appropriate for very small quantities or in case of failure of other production processes. Since individualization of products is strongly gaining in significance, forming processes have to be found, which are independent from expensive tools and equipment. Using driving as the process of choice to form sheet metal, the grade of automation of the forming process has to be increased. Numerically controlled driving, i.e. automated positioning and handling of the work piece during the production process, will need a conclusive simulation base. This paper provides results of the analysis of sheet steel angles formed by the driving sub groups of shrinking and stretching.


Procedia CIRP ◽  
2014 ◽  
Vol 18 ◽  
pp. 203-208 ◽  
Author(s):  
J. Enz ◽  
S. Riekehr ◽  
V. Ventzke ◽  
N. Sotirov ◽  
N. Kashaev

Sign in / Sign up

Export Citation Format

Share Document