Influence of material properties on the laser-forming process of sheet metals

The laser-forming process is a new flexible forming process without rigid tools and external force. The sheet metal is formed by internal thermal stress induced by laser. Material properties play an important role in laser forming. A three-dimensional coupled thermo-mechanical finite element model is established in this paper. The laser-bending process of a sheet blank is simulated numerically using the model. The relationship between the bending angle and material property parameters, such as Young's modulus, yield strength, thermal expansion coefficient, specific heat, and thermal conductivity, are studied in detail by FEM simulation. The simulations show that the material with lower Young's modulus and yield strength can produce a larger bending angle. The thermal expansion coefficient is nearly in direct proportion to the bending angle. The bending angle decreases with the increase of the heat conductivity. A bigger bending angle can be obtained for the material with lower specific heat and density. The research provides a good reference for selecting process parameters for increasing laser-forming efficiency. (c) 2004 Elsevier B.V. All rights reserved.