Forming Load Characteristics of Forward and Backward Tube Extrusion Process in Combined Operation

Abstract

Combined extrusion processes generally have advantages of forming in terms of the minimum deformation power since the material is pressed through two or more orifices simultaneously. This paper is concerned with the analysis of forming load characteristics of a forward-backward can extrusion process using thick-walled pipe as an initial billet. The combined tube extrusion process was analyzed by using a commercial finite element code. A thick-walled pipe was selected as an initial billet and the punch geometry has been chosen on the basis of ICFG recommendation. Several tool and process parameters were employed in this analysis and they are punch nose radius, backward tube thickness, punch face angle, and frictional conditions, respectively. The main purpose of this study is to investigate the effect of process parameters on the force requirements in combined extrusion process. The possible extrusion process to form a forward-backward tube parts in different process sequences were also simulated to investigate the force requirements in sequential operations, i.e. separate operations. It was easily concluded from the simulation results that lower forming load was predicted for the combined extrusion, compared to those for separate sequential operations. It was also revealed that the punch nose radius and the punch face angle have little effect on the force requirements and the forming load increases significantly as the frictional condition along tool-workpiece interface becomes severe. The simulation results in this study suggest that the combined extrusion process has strong advantage in terms of force requirements as long as the simultaneous material flow into multiple orifices could be closely controlled.

Investigating the process of shrinkage depression formation at the combined radial-backward extrusion of parts with a flange

“…Currently, the active implementation of combined extrusion processes in industry is constrained by the lack of detailed recommendations on determining the force parameters of the process, predicting shape change and defect formation [8][9][10][11][12][13][14][15][16][17].…”

“…A series of papers [8][9][10][11][12][13] are limited to studies of force parameters and phased shape change in the processes of combined extrusion. Work [8] analyzes the effect of geometric parameters and friction conditions in the process of direct-reverse-radial extrusion based on a finite element method employing the software ABAQUS (ABAQUS Inc., USА).…”

“…Work [8] analyzes the effect of geometric parameters and friction conditions in the process of direct-reverse-radial extrusion based on a finite element method employing the software ABAQUS (ABAQUS Inc., USА). Papers [9,10] report studying the force parameters and shape change of hollow parts in the process of combined extrusion, which are limited to modeling in Deform-2D (Scientific Forming Technologies Corporation (SFTC), USA). The combined extrusion processes were investigated in studies [11,12] by the methods of finite elements and the upper assessment (using rigid triangular elements).…”

Derivation of engineering formulas in order to calculate energy-power parameters and a shape change in a semi-finished product in the process of combined extrusion

“…An analysis of data from the scientific literature reveals that the main problem of studying the processes of combined extrusion with several degrees of metal flow is to determine the optimal kinematic parameters of the deformation process [6][7][8][9][10][11][12][13]. This, in turn, makes it difficult to obtain the information about the stagewise and limit change in the shape of a billet [6] and leads to complexities in the development of the technological mode.…”

“…In this case, the finite element method in ABAQUS software was used, however, the analytical dependences of power parameters and increments of a billet were not obtained. Article [8] is dedicated to the study of the process of combined reverse-direct extrusion of a pipe billet. The influence of geometric parameters of a tool and a part, as well as of friction conditions, on extrusion force was analyzed.…”