Heat Sink Effect on 6061 Aluminum Alloy Welds with Different Partial Aging Conditions

Partially aged 6061 aluminum plates were welded by the gas metal arc welding process. During the welding process, a cooling system to act as a heat sink was used to extract the heat coming out from the welding process. To determine the experimental weld thermal cycles, K type thermocouples were placed at the heat affected zone. Finite element was used to compute the thermal distribution and isothermal sections generated by welding. The temperature measurements, Vickers microhardness profiles and tensile tests were observed to be related with the microstructural β″ to β′ phase transformation. The over-aging of the heat affected zone tends to diminish when the heat sink is used as compared with the reference welding condition. An increase on tensile strength (about 5.8%) and ductility (close to 29%), for welds performed in partial aging materials with respect to the welds with artificial aging condition (6061-T6 alloy) was also observed.