A Study of Lubricated Direct-Extrusion Process of High-Strength and High-Melting-Point Materials, With Isothermal Surface of Die and Container

Abstract

Numerical solutions for an isothermal case are presented for the direct extrusion process of a cylindrical body with viscous plastohydrodynamic lubrication at high operating temperature and pressure. The extrusion pressure at die predicted by the present theory, and measured correspondingly by experiment are seen to agree well. As such, this agreement supports the validity of the assumptions in the present theory. For this typical experimental case, the additional data, which are not measured by experiment, are calculated by the present theory. Furthermore, a more fundamental understanding is provided for design data with regard to the interaction of the physical parameters such as extrusion ram speed, percent reduction in area, half of the included die angle, preheat billet temperature, exit pressure of lubricant film, lubricant properties, and extruded materials. These design data are offered in a form whereby they may be applied broadly to a variety of practical direct extrusion processes.