Copper wire drawing under internal hydrostatic pressure

• Grant number: 06/03583-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2006
• End date: August 31, 2007
• Field of knowledge: Engineering - Mechanical Engineering
• Principal Investigator: Antonio de Pádua Lima Filho
• Grantee: Tiago Filipe Soares da Cunha
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

The aim of this work is to compare the variation of drawing stress/force of copper wire, with and without lubrication by applying mineral oil under pressure using purpose built equipment. During assays, the copper wire will be progressively drawn in stages from an initial diameter of 4.0 mm down to 1.3 mm diameter. Ten drawing dies made of tungsten carbide (WC) will be used to make successive area reductions of approximately 20%, resulting in a total true deformation of approximately 225%. The effect of both hydrostatic lubrication and its absence on wire pulling force will be measured and compared. The lubricant will be applied under pressure onto the wire surface and also within the drawing frame. The pressurized mineral oil should decrease the pulling force since it forms an antifriction cone between the wire the bell and the approach angle (deformation section) of the drawing die. The action of the lubricant should also reduce the loading rate to achieve the necessary drawing pulling force. The degree of area reduction will also continue to be increased for testing with hydrostatic lubrication to demonstrate the potential of drawing wires further under these conditions. A load cell of 500 kgf will be used to measure the wire pulling force. The experimental results will be compared with theoretical models. The friction coefficients for each condition will be also computed utilizing different models.