Papers by Keyword: Aluminium Extrusion

Abstract: Liquid-solid microextrusion is one type of microplastic forming processes at elevated temperature and can be used in the forming of pins, screws, shafts, and gears in micro-scale. Microextrusion setup operated by use of ball screw was designed and fabricated by authors. Microshaft of diameter 1 mm was extruded in the liquid-solid state at different forming temperature from Al-Mg alloy ER5356 billet of 4 mm in diameter. Heating temperature in the furnace for billet were set 650, 700, 750, and 800 degree C which was corresponding to the forming temperature range from 475 to 631 degree C because of temperature drop during transfer from furnace to mold. Forming load ranged from 4kN to 8kN. Microstructural observation shows that the grain size was reduced greatly compared to the original billet material. Microindention hardness shows that the extruded pin was strengthened which caused by small grain size.

Abstract: A computational technique of rigid-plastic finite element method by using the Eulerian meshing method was developed to deal with large deformation problem in metal forming by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. During metal forming process, a workpiece normally undergoes large deformation and causes severe distortion of elements in finite element analysis. The distorted element may lead to instability in numerical calculation and divergence of non-linear solution in finite element analysis. With Eulerian elements, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. Four types of cold forging and sheet metal clinching were conducted to investigate the effectiveness of the presented method. The proposed method is found to be effective by comparing the results on dimension of the final product, material flow behaviour and punch load versus stroke obtained from simulation and experiment.