抄録
Paste extrusion is an important process used for manufacturing products based on particulate materials. From a theoretical viewpoint, paste extrusion resembles solid metal extrusion, for which extensive theory has been developed. In particular, exact solutions are available for many extrusion processes involving plane strain deformations, allowing extrusion pressures to be accurately determined in these situations. However, axisymmetric extrusion is more common in a paste flow context, and in this case simple alternative methods for estimating extrusion pressures are desirable.
In this article, we describe how exact solutions for plane strain extrusion can be applied empirically to axisymmetric geometries, to provide accurate estimates for extrusion pressures. The nominal extrusion pressures for plane strain and axisymmetric extrusions with equal area reductions appear to be similar, for both smooth- and rough-walled square-entry dies. The axisymmetric extrusion pressure can be estimated directly in the smooth wall case, while for rough walls, the contribution due to rigid sliding, away from the deforming zone, must also be considered.
Some new correlations describing combined results from slipline field solutions for plane strain extrusion are also presented.
