FEM Numerical and Experimental Study on Dimensional Accuracy of Tubes Extruded from 6082 and 7021 Aluminium Alloys

Abstract

The extrusion of hollow profiles from hard-deformable AlZnMg alloys by using porthole dies encounters great technological difficulties in practice. High extrusion force accompanies the technological process, which is caused by high deformation resistance and high friction resistance in extrusion conditions. As a result of high thermo-mechanical loads affecting the die, a significant loss of dimensional accuracy of extruded profiles can be observed. The different projects of porthole dies for the extrusion of Ø50 × 2 mm tubes from the 7021 alloy were numerically calculated and then tested in industrial conditions by using a press of 25 MN capacity equipped with a container with a diameter of 7 inches (for 7021 alloy and 6082 alloy for comparison). New extrusion die 3 with modified bridge and mandrel geometry and a special radial–convex entry to the die opening was proposed. FEM was applied to analyse the metal flow during extrusion, geometrical stability of extruded tubes and the die deflection. The photogrammetric measuring method was used to evaluate dimensional accuracy of tubes extruded in different conditions and geometrical deviations in porthole dies elements, especially the bridges and the mandrels. Research revealed a high dimensional accuracy of tubes extruded from the 6082 alloy and from the 7021 alloy by using original extrusion die 3, while much higher dimensional deviations were noted for tubes extruded from the 7021 alloy by using extrusion dies 1 and 2, particularly in relation to the circularity, centricity and wall thickness.

Tensile Behavior and Microstructure Evolution of an Extruded 6082 Aluminum Alloy Sheet at High Temperatures

“…The major alloying elements of 6082 alloy are magnesium, silicon and copper, and this alloy can offer favorable strength, excellent corrosion resistance, good resistance to fatigue and outstanding recyclability [7]. The increasing use of this alloy is based on the processes of heat treatments and plastic deformation with considerable mechanical properties [8][9][10].…”

FEM Numerical and Experimental Work on Extrusion Welding of 7021 Aluminum Alloy

“…From these results, the good surface quality and dimensional accuracy of the extruded products can be inferred. However, detailed studies of the geometric stability of tubes extruded by die 1 (which is the subject of another publication) indicated relatively large dimensional deviations of wall thickness, going beyond the values allowed by the relevant standard [37].…”

“…From these results, the good surface quality and dimensional accuracy of the extruded products can be inferred. However, detailed studies of the geometric stability of tubes extruded by die 1 (which is the subject of another publication) indicated relatively large dimensional deviations of wall thickness, going beyond the values allowed by the relevant standard [37]. The process parameters recorded during extrusion of the tubes in question indicate a metal discharge velocity from the die hole in the range 3.5-4.5 m/min, depending on the geometry of the porthole die used (Figure S8 in Supplementary File).…”

Multi-Objective Optimization of a Multi-Cavity, Significant Wall Thickness Difference Extrusion Profile Mold Design for New Energy Vehicles

“…Professional finite element analysis software such as Deform-3D, HyperXtrude, and Qform Excitation not only improves the accuracy of die design but also significantly shortens the design cycle. This software, through its highprecision simulation capabilities, can predict material flow, stress distribution, temperature changes, and potential defects before actual manufacturing, effectively reducing the amount of trial and error, lowering production costs, and improving the quality and consistency of the final product [4][5][6][7][8][9][10].…”