Effect of Process Parameters on Backward Extrusion of Environmental-friendly Bismuth Brass

The environmental-friendly bismuth brass bars of φ23.2 mm and φ6.5 mm were extruded on 28 MN backward extrusion machine.The effects of process parameters on forming process and product quality,such as extrusion temperature,extrusion velocity,degree of deformation,were discussed.The results show that the optimum extrusion temperature should be between 670℃ and 710℃,elongation coefficient λ should be less than 550,so metal flowing out velocity gets 3435 mm/s.It gives valuable information for determining process parameters in production.