The Experimental Investigation of Size Effect on Micro-cylinder Deformation in Coining Process

In micro-manufacture field, the micro-geometry is usually produced by the coining process, and therefore the researches on the coining process of micro-geometry are necessary. After designing and machining die with different diameters of micro-holes, the size effects on micro-cylinder deformation in the coining process are experimentally studied in this paper. The ratio of the micro-cylinder height h to micro-hole diameter D is selected as the evaluation criteria for the forming degree of micro-cylinder, and the effect of micro-cylinder size on the ratio h/D is studied. Using microscope, electron backscatter diffraction, and Vickers hardness test, the influences of grain distribution and orientation are also investigated. The research results could guide the manufacturing of the parts with micro-geometry.