The concepts described herein provide a method, system, and apparatus for joining, via welding, first and second members fabricated from an aluminum alloy including aluminum, zinc, and manganese, such as 7000-series aluminum alloys, and a resultant workpiece. A junction is formed by a first member being disposed contiguously to a second member. A welding machine generates a weld pool at the junction that includes liquified aluminum alloy. An ultrasonic transducer directs ultrasonic energy in proximity to the weld pool. In some embodiments, an electro-magnetic transducer directs electro-magnetic energy in proximity to the weld pool. The first member is fused to the second member at the junction upon solidification of the weld pool.