Investigation on microstructure and mechanical properties of Fe-based amorphous coatings prepared via laser cladding assisted with ultrasonic vibration

•A series of Fe-based amorphous coatings were fabricated via laser cladding assisted with ultrasonic vibration.•With increasing ultrasonic power from 0 W to 1000 W, the average thickness of the gradient crystallization zone increases from 46 μm to 81 μm and appears as a changed wave.•The gradient structure has an energy storage function that can release internal stress and reduce coating cracking.