The Dieless Drawing Process for the Elongation of Ultrafine Copper and Brass Wire

In this study, a new method of ultrafine copper and brass wires production was proposed. The proposed technology is based on the dieless drawing. The workpiece for the dieless drawing is a thin wire (100–200 μ) obtained by a conventional drawing method. The proposed technology is based on the implementation of a multi-pass incremental deformation. Moreover, in each pass, strain and strain rate sensitivity of flow stress should be positive and significant. The deformation parameters in each pass are determined based on the flow stress dependency on the strain, strain rate, and temperature. Therefore, plastometric tests of copper and CuZn37 alloy were performed. To estimate the temperature of deforming wire the FE modeling of dieless drawing was performed. The obtained data were used in the practical implementation of incremental dieless drawing technology. Roughness analysis was performed for brass samples. In the performed experiments tests, the dieless drawing will lead to an increase of roughness of the wire surface. However, this increase is relatively small. The value of Ra before the dieless drawing was 1.73 μ, and after deformation, it was 2.23 μ.