Welder can perform aluminum welding using both AC (alternating current) and DC (direct current) power sources. The selection of AC or DC currents depends on several factors such as base metal thickness, welding process, and desired weld properties.
Breakdown of AC and DC welding for aluminum-
1. AC Welding (aluminum)
AC welding is commonly used for aluminum welding. Because it helps to prevent the aluminum oxide layer, which forms quickly on the surface of the metal.
The alternating current causes the oxide layer to break up. It helps to clean the base metal surface during the welding process. Subsequently, this cleaning action improves the weld quality and penetration.
AC welding is suitable for a wide range of aluminum alloys. Additionally, it can handle both thicker and thinner aluminum sections effectively.
It provides good heat balance. This is important for preventing distortion and controlling the weld pool during the welding process.
AC welding is often used with Tungsten Inert Gas (TIG) welding processes, such as AC TIG or AC/DC TIG machines.
2. DC Welding (aluminum)
Welders can also use DC welding for welding aluminum. But, more commonly, it is used for thinner aluminum sections or specific applications.
Direct current can provide better penetration compared to alternating current. This can be advantageous when welding thinner materials or achieving deeper welds.
DC electrode positive (DCEP or reverse polarity) is typically used for aluminum MIG welding to achieve better cleaning action and weld penetration.
DC welding is often used with Metal Inert Gas (MIG) or Gas Metal Arc Welding (GMAW) processes, where a continuous feed of consumable wire electrodes is used.
Most importantly, AC welding is more commonly used for aluminum welding due to its cleaning action and versatility.