Magnesium Alloys are used in a wide variety of structural applications where light weight is important. That include: aerospace equipment and industrial machinery, such as textile and printing machines used for parts that operate at high speed, to minimize inertial forces.
The Magnesium alloy ER AZ61A Welding Rods Filler Metal is used for gas-tungsten-arc-welding (GTAW) of the following alloys:
AZ10A, AZ31B, AZ61A, AZ80A, ZK21A
Typical Chemical Composition:
Mg Rem. - Al 5.8/7.2 - Be 0.0008* - Mn 0.15/0.5 - Zn 0.4/1.5 - Cu 0.05* - Fe 0.005*
Ni 0.005* - Si 0.05* - altri 0.30* (*) max
Filler metals available in cut straight lengths in a variety of sizes and diameters.
Magnesium alloys are welded by the gas tungsten arc welding (GTAW) process using techniques and equipment similar to those used for aluminum. Argon, helium, or mixtures of these gases are used for shielding. Alternating current is preferred because of a combination of good arc cleaning action and good joint penetration, although direct current is also used.
Direct current with the electrode positive provides excellent cleaning action but is limited to thin base metal. Direct current with the electrode negative is sometimes used for mechanized welding with helium shielding gas to provide deep joint penetration.
GTAW is generally recommended for the welding of magnesium alloy castings. Welding is usually limited to the repair of defects in clean castings.
Gas Metal Arc Welding (GMAW), Pulsed GMAW and short circuit GMAW are used for magnesium alloys. Higher welding current, to produce spray transfer of the filler metal without pulsing, is also used. The higher filler metal deposition rate of this process reduces the welding time, thereby reducing weld distortion and fabrication costs. Argon is generally used as a shielding gas; occasionally mixtures of argon and helium are used.
As with other metals, the cleanliness of Magnesium Alloys, is important for obtaining sound joints of acceptable quality: therefore the surfaces and edges to bi joined must be cleaned from oil, grease, dirt or oxide with chemical cleaner (solvent).
After degreasing is a good practice to do a good mechanical brushing with stainless steel brush.