Título

FRICTION AND STRESS EVALUATION OF COPPER WIRE DRAWING UNDER DIFFERENT LUBRICATION CONDITIONS

FRICTION AND STRESS EVALUATION OF COPPER WIRE DRAWING UNDER DIFFERENT LUBRICATION CONDITIONS

Autoria

Filho, Antonio de Pádua Lima; Ferreira, Igor Ribeiro; Cataneo, Felipe Biava; Cunha, Tiago Filipe Soares da; Mantovani, André

DOI

10.5151/2594-5327-23437

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Resumo

ASTM C10100 W annealed copper wires with an initial diameter of 4.3 mm were drawn to a final diameter of 1.3 mm using a mineral oil lubricant of 0.06 Pa.s viscosity under hydrostatic pressures of approximately 35 MPa. Ten wire drawing dies (of 3.6 mm, 3.2 mm, 2.9 mm, 2.6 mm, 2.3 mm, 2.1 mm, 1.9 mm, 1.7 mm, 1.5 mm and 1.3 mm in diameter) were used to produce a total cross-sectional reduction of approximately 225%. Wire drawing forces under oil hydrostatic pressure with a graphite lubricant were compared to wire drawing forces without any lubricant. A measuring system was used to record the wire drawing forces over time and to study the frictional behaviour of the drawn wires. A wire drawing machine with a speed of 8 mm/s was used to verify the coefficient of friction fore wires drawn at low strain rates. Lubrication regimes were analysed for oil under hydrostatic pressure. The quasi-hydrodynamic regime ranged from 2.3 mm to 3.6 mm for the wire drawing die. An analytical model for calculating the wire drawing force/stress was developed to obtain the distribution of friction coefficients at each reduction of wire diameter. By controlling friction forces, it is possible to save energy and materials, as well as to determine the die replacement frequency. Wire drawing processes are used extensively in industry and research and will benefit from knowledge of the best working conditions.

 

ASTM C10100 W annealed copper wires with an initial diameter of 4.3 mm were drawn to a final diameter of 1.3 mm using a mineral oil lubricant of 0.06 Pa.s viscosity under hydrostatic pressures of approximately 35 MPa. Ten wire drawing dies (of 3.6 mm, 3.2 mm, 2.9 mm, 2.6 mm, 2.3 mm, 2.1 mm, 1.9 mm, 1.7 mm, 1.5 mm and 1.3 mm in diameter) were used to produce a total cross-sectional reduction of approximately 225%. Wire drawing forces under oil hydrostatic pressure with a graphite lubricant were compared to wire drawing forces without any lubricant. A measuring system was used to record the wire drawing forces over time and to study the frictional behaviour of the drawn wires. A wire drawing machine with a speed of 8 mm/s was used to verify the coefficient of friction fore wires drawn at low strain rates. Lubrication regimes were analysed for oil under hydrostatic pressure. The quasi-hydrodynamic regime ranged from 2.3 mm to 3.6 mm for the wire drawing die. An analytical model for calculating the wire drawing force/stress was developed to obtain the distribution of friction coefficients at each reduction of wire diameter. By controlling friction forces, it is possible to save energy and materials, as well as to determine the die replacement frequency. Wire drawing processes are used extensively in industry and research and will benefit from knowledge of the best working conditions.

Palavras-chave

Wire drawing; Copper wire; Lubrication; Friction.

Wire drawing; Copper wire; Lubrication; Friction.