Method for preparing metal matrix amorphous/nanocrystalline composite layer

The invention discloses a method for preparing a metal matrix amorphous/nanocrystalline composite layer, which comprises the following steps: preparing metal matrix amorphous solid or preparing a metal matrix amorphous coating on the surface of an object by a conventional method; and putting the prepared metal matrix amorphous solid or the object with the metal matrix amorphous coating into water, at room temperature and under ultrasonic environment, making water vibrated at a frequency between 6.0 and 30.0kHz with a ultrasonic transducer to act on the metal piece in the water or the surface of the object, making the ultrasonic power between 100 and 500W, and forming the amorphous/nanocrystalline composite layer on the metal piece or the surface of the object. After the amorphous metal piece or object with the amorphous coating is crystallized by the method, nanocrystalline is formed on the surface in certain depth, an amorphous/nanocrystalline composite texture is obtained, and the high corrosion resistance