| An innovative study on the feasibility of using high energy laser to deform plastic and superplastic materials was conducted in the High Energy Laser Materials Processing Laboratory HELP of Michigan State University. This novel superplastic sheet forming technique is vastly different from the conventional superplastic forming process. In this study, a high energy CO{dollar}sb2{dollar} laser was controlled to perform heating, at selected and programmed locations, on a superplastic sheet which is situated on a box containing a gas at higher than ambient pressure, or vacuum. Both the geometry of the heating path and the amount of heat input could be precisely implemented through computer numerical control (CNC). Convex or concave bulges, which will delineate a desired shape, can be obtained.; With the experimental results, the feasibility of laser die-less superplastic forming has successfully demonstrated the economic and practical potential in complex shape forming. It is even possible to control not only the final thickness, but also the deformed shape by using this technique. Since the quality of the workpiece can be controlled at any region of processing without the use of a die, a complex fabrication seems possible. |
