Incremental in-plane bending, which was developed by the authors, is a new flexible manufacturing technology for the small-lot production of sheet metals with various bending radii. A sheet metal is bent incrementally by inclined punch beating. Beating angle is an important factor of in-plane bending. The effects of beating angle on in-plane bending were investigated. Beating force, the distribution of thickness strain and bending radius were experimentally determined. It was clarified that beating angle is an important factor that affects bending radius. Moreover, deformation simulation was carried out and the effect of beating angle on the in-plane bending mechanism was compared with experimental result. It was found that there is a critical beating angle for obtaining the minimum bending radius for fixed indentation and width of sheet metals.

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In this study, the dynamic explicit elastic crystal viscoplastic finite element analysis code and combination method were employed to model a dual-phase steel sheet for a newly developed texture design system. The dual-phase steel consisted of martensite and ferrite phases. The crystal orientation distributions of the ferrite and martensite phases were measured by EBSD (Electron Back Scatter Diffraction Camera) and ODF (Orientaion Distribution Function) analyses, and the hardening evolutions of the two phases were identified by uni-axial tensile tests. By employing the combination algorithm to compound the two phases, FE models for assessing plastic anisotropy and formability were obtained. The feasibility of our finite element modeling scheme was verified by comparing the deformation and strain distributions in square-cup deep drawing and VDI benchmark stretch-draw experiments.

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Powder metallurgy methods have disadvantages resulting from multistage processing, typically consisting of powder production, sizing, compaction and sintering, and this processing often leads to a high cost and low quality because of oxide contamination. As a new powder metallurgy process, it is considered that near-net-shape preforms can be obtained in one step directly from molten metal by an integrated atomization/deposition operation. In the end of the 1960s, this concept was introduced by the Swansea University and adopted by Osprey Metals Co. in the UK. Consequently, this process came to be known as the Spray Deposition Process, Spray Forming Process or Osprey Process. In this study, a new metallurgy process without using powder has been developed to obtain dense preforms with fine-grained and macrosegregation-free microstructures. This technology requires no multistage processing as mentioned above because of the rapid production of solidified metals in thick film sections in one step directly from melt spinning by the integrated filament/deposition operation. The process has been named the Ejection Forming Process, for which a patent is pending in the case of application to AZ91 magnesium alloy. It is shown that the most suitable ejection temperature ranges from 650 to 710°C, which far exceeds the liquidus and a very fine grain size of 15∼20μm is obtained.

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