Experimental Analysis for Lubricant and Punch Selection in Shear Extrusion of Aa-6063

Ojo So Erinosho M

doi:10.4172/2169-0022.1000174

Abstract

Shear extrusion is a forming process which is based on combined backward cup-forward rod extrusion. This extrusion process is attractive due its potential to achieve severe plastic deformation thus enabling texture and microstructural control of materials. Furthermore, the economic potential of shear extrusion for mass production and production of complex shapes provides for numerous applications in automotive, transportation, aero-space and other industries. However, a trending challenge in the use of this method for complex shapes is the design and selection of tools to achieve a high quality product. This paper focuses on deep study of shear extrusion of AA-6063. The process was studied experimentally using variables which affect the forming load as well as the quality of the product. It is concluded from the load-displacement and stress plots that a punch with large diameter and small punch land is desirable for easy forming of the material during shear extrusion. Analysis of the effect of lubricants on deformation load and stress shows that palm oil lubricant remains the best lubricant of the four lubricants examined since its gives the minimum load obtained during shear extrusion.

Highlights

Shear extrusion theory was derived from combined backward cup- forward rod extrusion (BC-FRE) theoryand it involves shearing deformation during the metal forming process, a characteristic which makes the process to be labour saving
Chang and Mousavi showed that the extrusion force in shear-extrusion method of severe plastic deformation for fabrication of metal shapes with ultra-fine structures is far lower than that of simple forward rod extrusion (FRE) or backward cup extrusion (BCE) [1,2]
4 punches of different diameters each made up of 3 different punch land lengths and 4 lubricants were utilized as process variables to optimize the selection of lubricants and punch for the shear extrusion operation

Summary

Introduction

Shear extrusion theory was derived from combined backward cup- forward rod extrusion (BC-FRE) theoryand it involves shearing deformation during the metal forming process, a characteristic which makes the process to be labour saving. The use of shear die in the extrusion of complex shapes leads to a complicated problem of metal flow imbalance that often results in shape defects and to obtain a straight and true product in size, the design of the location of the die orifice and the specification of the die land length is of paramount importance [11,12,13]. Other die process parameters which may affect the quality of the extrudate are the shape ratio of the billet, extrusion ratio and the capacity of the extrusion press [14].

Results

Conclusion