Deformation behaviour during loading and unloading is studied in compression of an aluminium plate with a high ratio between the diameter and the thickness by a DLC coated die. A compressed plate becomes thinner during unloading after the plate is compressed to a larger reduction in thickness in loading. The plastic deformation of a compressed plate during unloading is confirmed by measuring the increase of the plate diameter during unloading. The optimum profile of a die crown approaches to the reverse shape of the elastic deflection of a flat die at the loading stroke end with increasing reduction in thickness.

中文翻译：

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板材压缩卸载时工件的塑性变形

加载和卸载过程中的变形行为是通过 DLC 涂层模具压缩具有高直径和厚度之间的比率的铝板来研究的。在板被压缩到更大的厚度减少量之后，在卸载过程中，被压缩的板变得更薄。卸载过程中压缩板的塑性变形是通过测量卸载过程中板直径的增加来确定的。随着厚度的减少，模具冠部的最佳轮廓在加载行程结束时接近于平模弹性变形的反向形状。