Mechanical properties of AA6XXX WELDMENT after Cryogenic Treatment

In this book, the effect of the welded shallow cryogenic treatment (SCT) on hardness, wear and microstructure of AA6061-T6 and AA6082-T6 weldments were studied. Gas tungsten arc (GTAW) welding of Aluminum 6xxx leads to significant loss of hardness in the welded region compared to the base material hardness due to overaging. Shallow Cryogenic treatment can be used to improve the mechanical properties of aluminium alloys. The GTAW welding was carried out with different heat inputs by varying the welding speed. The hardness and microstructure were evaluated for wear as-welded and post-weld shallow cryogenic treated specimens in the welded region. It is found that the hardness & Micro Structure of the welded AA6061-T6 and AA6082-T6 has Enhanced. This is due to the reactivation precipitation sequence in the welded region.