Question 6 (Max 8) A welding operation will take place on carbon steel. The desired welding speed is around 20 mm/s. If an arc welding power supply is used with a voltage of 12 V, what current is needed if the weld bead width is to be 5 mm. Assume an efficiency of 75% of the heat source. A ratio weld width-weld depth of 1.3 is preferred to reduce the risk of center weld cracking. What current would you apply in case aluminium alloy? Material Specific energy J/mm Aluminium alloys Cast iron Copper Bronze (900u - 105n) Steels Stainless steels Titanium 2.9 7.8 6.1 4.2 9.1. 10.3 9.3-9.6 14.3