Deep Drawing Behavior of Metal-Composite Sandwich Plates

The deep drawing behavior of metal-composite sandwich plates, or fiber-metal laminates, in which aluminum or steel sheets are used as the face layer and composite materials are used as the core layer, is discussed in this work to find the workpieces without fractures and wrinkles. Two types of aluminum, 1050 and 6061, are considered their suitability as face sheets. The preheat effect of aluminum 6061 on formability is also investigated. When steel sheets are used, the effect of blank-holder pressure is included. In addition, to understand the deformation of fabric composite, pure composite laminates are deep drawn. The results of composite laminates show that after drawing, the weft and warp lines are shorter than the other radial lines, causing the specific deformed shape and the variation of the fiber intersection angle. For Al-composite sandwich plates, fractures and wrinkles are easy to occur. Even though the fracture and wrinkle conditions are released with the increase in preheating temperature of aluminum 6061, it may be not enough. For the deep drawing of the steel-composite sandwich plates, in which fractures are avoided, the increase of blank-holder pressure could reduce the wrinkle number. Hence, good quality workpieces without fracture and wrinkle could be obtained when the blank-holder pressure is high enough.