The zinc base filler metals are mainly made up of zinc element , with a little copper , aluminum , tin , cadmium etc . They are mainly used to solder aluminum and aluminum alloy , also solder copper alloy and steel etc . They usually adopt oxyful welding ,ultrasonic wave welding , salt bath dip brazing ,furnace welding , etc . In the process of soldering , the flux must be used together with the zinc filler metals . After soldering , the dregs of a flux must be completely cleared away . |  |