Liquid-solid microextrusion of aluminum alloy

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.