Aluminum alloy has the advantages of light weight, good strength, excellent corrosion resistance and beautiful surface, and has been widely used in industry. Among them, the application of A356 cast aluminum alloy is the most common, especially the improvement of A356 cast aluminum alloy process. It is changing daily, such as the practical application of squeeze casting and gravity casting methods. The squeeze casting and gravity casting of A356 alloy were fused-weld by using gas tungsten arc welding (GTAW) process. The effects of castings and T6 treatment, filler metals and shielding gas flow rates on the qualities of weldments were fully investigated.
Experimental results showed that the fusion zone of squeeze casting produced a greater pore number and pore volume than that of gravity casting caused. Use of filler metal (ER5356 or ER5556) significantly decreased the pore number and pore volume comparing the metal ER4043 filler. After T6 treatment, the welded fusion zone was greater than welding as-cast casting. Increasing shielding gas flow rate decreased the pore number and pore volume of fusion zone and in fusion zone could be remarkably improved.
Keywords: Squeeze Casting, Gravity Casting, GTAW