METHOD OF EXTRUSION Russian patent published in 1998 - IPC

FIELD: plastic metal working, in particular, methods of extrusion of combined in thickness blanks, for making pipes with clad working surface. SUBSTANCE: method of extrusion, mainly, of combined blanks with longitudinal layering having two component parts each, located in each other; external one is made, for instance, of less strong material with which combined blank is assembled to form shoulder on one of end faces, one component part of blank is fixed with respect to the other. Then, combined blank is heated, installed on needle with subsequent extrusion through conical female die by its placing in container and with application of axial compressing force to flat end face of combined blank through pressing disk. Fixing of blank components is carried out in two stages. At the first stage, bearing surfaces of blank components are located at some distance from each other, and by application of axial compressing force to the working end face of external component, combined deformation of blank components in radial direction is effected by simultaneous extrusion of material of external component into gap between bearing surfaces of end faces and formation of shoulder on the side of applied force. At the second stage, bearing surface of end faces of blank components are combined by applying axial compressing force to working end faces of both components, and plastic flow of material of external component relative to bearing end face of internal component. EFFECT: provision of automation in assembly process of combined blanks. 1 cl, 5 dwg