Numerical simulation of edge effect in plasma arc forming of sheet metal
Edge effect was found in plasma arc forming process of sheet metal, which reduces the forming accuracy of sheet metal seriously. In order to reveal the forming mechanism and forming laws of the edge effect. A numerical model on forming of sheet metal using plasma arc with scanning along a straight line was established and the forming mechanism and forming laws of the edge effect were studied. The results showed that the upper material and the lower material of the edge were produced shrinkage along the scanning path and both shrinkage were different. The size relationship of the two shrinkage determines the direction of edge warp. The difference of the two shrinkage affects the warpage of the edge. In the comprehensive effect of shrinkage and warpage, the non scanning region in the both sides of the scanning path appears bulge or depression. The numerical analysis results were agree well with the experimental results. The conclusions provide a theoretical basis to reduce the effect of the edge effect on the accuracy of the sheet metal forming.
Rapid prototyping of sheet metal components by plasma-jet forming
Abstract Conventional precision forming of sheet metal components requires the use of mechanical tools. However, during product development, different tools may be required to form various shapes, thus necessitating significant tool cost and lead time. If a rapid prototyping process were available such that the required shapes can be formed without the need for hard tools, the potential reduction in product development cost and lead time could be quite significant. Moreover, such a process could be used for very short run production where it would be uneconomical to amortize tooling cost over a small number of manufactured pieces. To explore the potential for flexible forming without tools, various researchers have used a laser beam as a heat source to induce deformation in sheet metals by means of thermal stresses. Some success has been demonstrated with such an approach. However, laser systems have several disadvantages, which can be circumvented by the use of a plasma-jet as a heat source. This paper describes the use of a robotic system to manipulate a non-transferred arc plasma torch as a controllable heat source to generate internal stress in sheet metals, thus causing plastic deformation without the necessity of hard tooling. Simple linear bends have been produced in several sheet materials of 0.8 mm thickness to evaluate the effect of various process and material parameters. Some evaluation of material properties resulting from the bending operation has been conducted. The key process parameters affecting the rate of bending have been identified as those governing the amount and rate of heat input to the sheet surface, and the temperature gradient developed between the front and back sheet surfaces. It has been demonstrated that the principal sheet metal physical property affecting bending behavior is the thermal conductivity. Results are presented to illustrate these various effects.
Synergy of Laser Material Processing and Metal Forming
Abstract It will be shown, on the basis of selected examples in the field of metal forming, how metal forming and laser beam processing can be combined in a synergetic way. A characteristic of metal forming is its ability for large scale manufacturing with high quality. Laser material processing is characterized by a high process, product, and quantity flexibility. Synergetic combinations of both processes enable completely new solutions for products and technologies. Although most of these developments are still in their initial phase, the first industrial applications have already proved their potential economical viability.