Optimization of a cold wire drawing technological process

Abstract

In this paper are presented theoretical methods, based on calculation of the strain stress state, by the means of the lower and upper bound solution, enabling the analysis and optimization of the cold wire drawing technological process, for the metals and alloys to which the Hollomon equation applies. Theoretical calculations were performed with standard die semi-angles, according to DIN 1546 and DIN 1547. The passes schedule calculation of the technological drawing processes were done according to the Ermanok and Duckfield methods, in order to achieve thin wire production for the alloy CuNi2Si. The production, by all applied passes schedule variants, involved a tungsten carbide die with a semi-angle of 7° and of a diamond die with a semi-angle of 9°. Using both methods wire production was achieved using CuNi2Si bronze, with diameter of 0.200 mm, having characteristics enabling its application for practical use. Furthermore, it was found that for this alloy the effective stress curve can be mathematically defined by the Hollomon curve.