Micro-Formability Of Fine Grain Copper Fabricated By Electrodeposition

With the rapid development of the micro electro mechanical systems, the requirements of microparts become more and more urgent. As one of micro manufacture ways, research of the technology of micro forming has been the hot point of plastic forming. The infection of material to micro-forming and the size effect in micro-forming has been the basic problems in the research of micro-forming. In this paper, a thin copper sheet of fine crystal which is adapt to micro-forming is made by electrodeposition method. The size effect in its simple tension and its micro-forming ability is researched.In this paper, we used pulse electrodeposition method to prepare a different thickness thin copper sheet. SEM study of copper surface shows that the crystal size is uniformity and material is coMPaction. After heat treating, the thin copper sheet whit different crystal size is got.The tension test at room temperature is used to study the size effect of thin copper sheet with different crystal size, different thickness and different strain rate. The result shows that whit the reduce of crystal size and the increase of thickness, material's elongation percentage and strength is become more and more higher; and material is not sensitive to the strain rate. The free surface layer model is founded to explain the size effect of the flow stress in micro forming. The uniformity of deformation between inter grain and grain boundary is used to explain the size effect of elongation percentage in micro forming. The high temperature tension test is used to research material's mechanic property at high temperature.A high temperature bulging test of the thin copper sheet is processed to study the biggest bulging force and the ratio of the bulging height and the diameter of female die when the diameter of bulging female die is different. In this test the thickness of the thin copper sheet, the diameter of female die and the rounding angle of female die is of direct ratio. The result shows that the biggest bulging force and the ratio of the bulging height and the diameter of female die is increased with the increase of the diameter of female die. The deep drawing test is processed at room temperature. A deep drawing part with diameter 1mm and...