Variation of apparent mechanical anisotropy of cold-formed embossed sheet by annealing

Recently, with the demand of car lightweight, more and more high rigidity and formability material are required. So in order to achieve the lightweight, a good method is essential. [1] Although the thin sheet metal has light weight, the performance is changed to be lower with the sheet metal become thinner. In generally, the sheet metal has an anisotropy which depends on the aggregate structure. It have been investigated that by the embossing process the sheet metal is given new properties and the anisotropy. It’s also investigated that the embossing process can improve the formability of the sheet metal. In this study, we used aluminum embossed sheet, and annealed the embossed sheet with different temperature. From the result, the variations of apparent mechanical properties of the embossed sheet by tensile test is confirmed. Furthermore, because annealing process can remove the work hardening, anisotropy derived from the embossing sub-macro structure was more obviously investigated.