The invention relates to an ultra-thick
hydrogen-free
diamond-like film and a preparation method thereof. A Cr bonding layer coats the upper part of a
metal matrix, the upper part of the Cr bonding layer is provided with a C / C multilayer
composite film, and the C / C multilayer
composite film is formed through alternating deposition of a soft C film and a hard C film. The preparation method comprises the following steps of (1) pretreatment of a workpiece, (2)
ion cleaning, (3) preparation of the Cr bonding layer, and (4) preparation of the C / C multilayer
composite film. According to the film andthe preparation method thereof, the soft and hard alternating C / C multilayer film is prepared by controlling a bias
voltage of the matrix by using a vacuum
ion plating technology, all
layers of interfaces are matched with one another, the film has good
binding force and
toughness, the induced effect generated by
ion bombardment under high bias
voltage causes a SP2 bond in the film to be transformed to a SP3 bond, and the
wear resistance of the
diamond-like film is enhanced. According to the homogeneous multi-layer structure, the
hardness of the film is up to 40 GPa, the
coefficient of friction is less than 0.15, and good durability is achieved, so that the
engineering application range of the
diamond-like film is expanded.