Composite preparing technology of ultra-fine crystalline/nano-crystalline Cr coating

The invention discloses a composite preparing technology of ultra-fine crystalline/nano-crystalline Cr coating. The composite preparing technology comprises the following steps that firstly, surface modification and surface shape improvement are conducted on the surfaces of base materials by adopting an electron beam, the surfaces of the materials are cleaned through the purification function of the electron beam, and dislocation is generated in surface layers of the materials to form an atomic diffusion channel; then a Cr layer which has the good wear resistance, heat resistance and corrosion resistance are brush-plated on the surface of a generated dislocation layer by adopting an electro-brush plating technology, and the thickness of the Cr layer is 10-100[mu]m; and then annealing treatment is conducted on a formed electroplated layer, then the electroplated layer is crystallized into ultra-fine crystalline/nano-crystalline, sediment element is promoted being diffused, a diffusing layer is formed, mechanical bonding of a base and the coating is transformed into metallurgical bonding, and the bonding force of the coating and the base is enhanced. According to the composite preparing technology, the wear resistance and corrosion resistance of the coating surface are good, and meanwhile, the purposes of large-area spraying on the surfaces of the base materials and the thick coating thickness can be achieved.