Extrusion is a well established technology for the production of complex sections of aluminum alloys. Thixo-extrusion in comparison to traditional hot-extrusion offers several advantages such as lower extrusion and friction forces, higher material fluidity, longer tool life, to name a few. Aluminum alloy 5182 is an important commercial alloy characterized by high strength and ductility, high corrosion resistance and good formability; it is commonly used for the production of wrought automotive components and, because of its wide solidification range, it is also suitable for semi-solid applications. The aim of this paper is to evaluate the effects of different routes of making the 5182 alloy feedstock for semisolid processing and to attempt the shaping of the alloy through the thixo-etrusion process using a ceramic tool. Particularly, three different methods were investigated: near-liquidus casting, roll-casting using a cooling slope, and ultrasonic treatment of the alloy in the semi-solid range. All the produced samples were characterized by metallographic analysis in order to measure the globule size and the shape factor, as the main criteria for assessing thixo-formability.
The effect of fabrication method on the microstructure of 5182 aluminum alloy feedstock for thixo-extrusion
POLA, Annalisa;ROBERTI, Roberto
2008-01-01
Abstract
Extrusion is a well established technology for the production of complex sections of aluminum alloys. Thixo-extrusion in comparison to traditional hot-extrusion offers several advantages such as lower extrusion and friction forces, higher material fluidity, longer tool life, to name a few. Aluminum alloy 5182 is an important commercial alloy characterized by high strength and ductility, high corrosion resistance and good formability; it is commonly used for the production of wrought automotive components and, because of its wide solidification range, it is also suitable for semi-solid applications. The aim of this paper is to evaluate the effects of different routes of making the 5182 alloy feedstock for semisolid processing and to attempt the shaping of the alloy through the thixo-etrusion process using a ceramic tool. Particularly, three different methods were investigated: near-liquidus casting, roll-casting using a cooling slope, and ultrasonic treatment of the alloy in the semi-solid range. All the produced samples were characterized by metallographic analysis in order to measure the globule size and the shape factor, as the main criteria for assessing thixo-formability.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
