Plastic anisotropy of ultra-thin rolled phosphor bronze foils and its thickness strain evolution in micro-deep drawing
Plastic anisotropy of ultra-thin rolled phosphor bronze foils and its thickness strain evolution in micro-deep drawing
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DOI：
10.1016/j.matdes.2013.11.048
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发表时间：
2014-04
影响因子：
8.4
通讯作者：
Tetsuhide Shimizu;M. Ogawa;M. Yang;K. Manabe
中科院分区：
文献类型：
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作者：
Tetsuhide Shimizu;M. Ogawa;M. Yang;K. Manabe
在钣金成形技术中，金属箔通过将工艺尺寸小型化，在生产具有高纵横比三维形状的微部件方面具有很大的优势。为了对生产现场现有的轧制金属箔进行表征，并阐明其强各向异性特性对微片成形性的影响，对厚度为20 ~ 300 μm的磷青铜箔进行了拉伸试验和微深拉深试验。以Lankford值（r值）作为常规板料成形性的有效参数，研究了超薄轧制箔的r值与其在微深拉深中的适用性之间的关系。超薄卷箔由于{11 0}和{11 1 1}质地较强，具有较高的值。虽然该值的面内趋势与微拉伸杯的厚度分布有很强的相关性，但得到的较薄金属箔的较高的er值并不对应于较薄金属箔的较低的成形性。将表面粗化引起的厚度不均匀作为指示薄轧金属箔成形极限的相关参数。实验证明了表面形貌取向和缺陷等几何各向异性对超薄轧制金属箔不稳定变形的重要性。
Metal foils are highly advantageous for producing microcomponents with high-aspect-ratio three-dimensional shapes by miniaturizing the process dimensions in sheet-metal-forming technologies. To characterize existing rolled metal foils at manufacturing sites and to clarify the impact of its strong anisotropic properties on micro-sheet formability, tensile tests and micro-deep drawing tests were performed on phosphor bronze foils with thicknesses of 20–300 μm. Focusing on the Lankford value (r-value) as a useful parameter for conventional sheet-metal-formability, the relation between ther-value of ultra-thin rolled foil and its applicability in micro-deep drawing is investigated. Ultra-thin rolled foil is characterized with a higherr-value due to the strong texture of {1 1 0} and {1 1 1} textures. Although the in-plane tendency of ther-value showed a strong correlation with the thickness distribution of micro-drawn cups, the obtained higherr-value for thinner foils does not correspond to the lower formability of thinner metal foils. As relevant parameter for indicating the forming limit for thin-rolled metal foils, the nonuniformity in thickness due to surface roughening is introduced. The importance of a geometrical anisotropy, such as orientation of surface topography and defects, for the unstable deformation of ultra-thin rolled metal foils is experimentally demonstrated.