Weldability of Cu54Zr22Ti18Ni6 bulk metallic glass by ultrasonic welding processing

•Bulk metallic glasses is crystallized by ultrasonic vibration.•Successfully welded 1 mm thick Cu base BMG without any evidence of crystallization.•Ultrasonic welding processing shows a potent capability for joining BMG.

Cu54Zr22Ti18Ni6 (numbers indicate at%) bulk metallic glass with glass forming ability of 6 mm was joined using ultrasonic welding. After welding fully amorphous materials, crystallization was investigated using micro area x-ray diffraction, scanning electron microscopy, and differential scanning calorimetry. However, there was no crystallization through the joint and the weld interface could not be ascertained. In view of joint morphology and phase stability, ultrasonic welding processing shows a potent capability for joining bulk metallic glass materials.