Title: Parametric optimisation of power in hydrostatic extrusion

Authors: A.H. Elkholy

Addresses: Mechanical Engineering Department, Kuwait University, P.O. Box 5969, Code 13060, Kuwait

Abstract: The process of hydrostatic extrusion has gained great publicity in recent years because of its simplicity and low cost. The material to be extruded is in contact with the die only. In conventional extrusion, the material is in contact with three components, mainly the ram, the chamber, and the die. Therefore, the power required to extrude the produce is less in hydrostatic extrusion. Add to this, the frictional losses are kept to a minimum because of hydrodynamic lubrication that takes place at relatively high extruding speeds. This will prevent the product from coming into contact with the die. In this study, an analytical model for studying hydrostatic extrusion is introduced. The model is used to investigate various parameters affecting extrusion. These parameters are mainly: die cone angle, sample reduction ratio (ratio of billet diameter to product diameter), friction coefficient, extrusion and back pressure ratio, and die shape. The model is extended to optimise the aforementioned parameters for better product, minimum power requirements and small frictional losses. To gain recognition, the model was substantiated experimentally using three commonly used engineering materials. The correlation between the analytical and experimental results are found to be in good agreement.

Keywords: hydrostatic extrusion; parametric optimisation; analytical modelling; die cone angle; sample reduction ratio; friction coefficient; back pressure ratio; die shape; power requirements; frictional losses.

DOI: 10.1504/IJMPT.1997.036375

International Journal of Materials and Product Technology, 1997 Vol.12 No.4/5/6, pp.379 - 388

Published online: 02 Nov 2010 *

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