RAPID SOLIDIFICATION WELDING OF ULTRA--THIN Zr55Cu50Al12Ni3 AMORPHOUS FOILS

The rapid solidification welding of Zr55Cu30Al12Ni3 amorphous foils with the thickness of 25---35 μm was conducted using a micro--type capacitor discharge welder. XRD analysis shows that the joint presents still amorphous structure under the rapid solidification welding conditions. The joint cooling rate calculated is high up to 106 K/s, which is much higher than that of critical cooling rate of amorphous Zr base alloy, and effectively suppresses the crystallization of joint zone. The micro joints with the size of 60---90 μm in diameter are produced and there are no welding defects such as porosity and inclusions within the joints. The joint shear strength is up to 1141 MPa. Contributing to higher electrical resistivity, the welding energy for welding metal glass foils is lower than that of crystallized metal foils remarkably.