Effect of Sheet Thickness and Grain Size on Forming Limit Diagrams of Thin Brass Sheets
Various metals and alloys have huge applications in the form of very thin sheets to manufacture parts such as micro metallic components for electronics and MEMS. In manufacturing of metallic components using very thin sheets, the material behaviour changes significantly with miniaturization due to the size effects—the ‘grain size effect’ and the ‘feature/specimen size effect’. Due to this, formability of very thin sheets depends on sheet thickness to grain size ratio (t/d). But, forming limit diagrams use in FE software meant for prediction of failure are plotted without incorporating the grain size effect and the plane strain condition of Forming Limit Diagram (FLD0) is calculated based on strain hardening exponent (n) and sheet thickness (t). In view of this, the present work is aimed at an investigation of grain size effect (t/d) on FLD0 of very thin brass sheets to achieve an improvement in accuracy of formability prediction in FE Analysis (FEA). In the present work, forming limit diagrams of very thin sheet specimens of CuZn36 brass (50–200 μm) have been experimentally determined.
KeywordsFormability Grain size effect Forming limit diagrams
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