THEORETICAL AND EXPERIMENTAL RESEARCHES FOR FRICTION COEFFICIENT DETERMINATION IN ALUMINUM EXTRUSION

The paper tackles the problem of needed forces for direct and indirect extrusion processes. These processes require very considerable forces, even for easy deform materials, as aluminum. Although is a perform procedure, with high precision and productivity, that considerable forces constitute an impediment for extrusion application on a large scale. A solution for force reduction is reducing friction between deformation tool and piece. The tests were made using different lubricants inserted on deformation tool piece contact. For each lubricant was determinate the friction coefficient. Using the adequate lubricant permits reduction of friction coefficient until 60% in proportion to dry friction. The paper establishes a method for extrusion friction coefficient determination and due measurement stand, installed on universal trial machine for extension and compression.