The invention belongs to a
surface engineering technology and in particular relates to a high-
hardness and low-
friction coefficient plating layer with a nanometer multilayered
amplitude modulation structure and a method for preparing the same. A Cr-Si-N plating layer is plated by an unbalance magnetron
sputtering ion plating method in a closed
magnetic field. In preparation, the input power of Cr target current is 2 kilowatts; and the input power of Si target current is changed within the range between 0.3 and 0.7 kilowatt so as to adjust the content of
silicon in the plating layer. When a CrN
transition layer and the Cr-Si-N plating layer are deposited, the flow of the introduced
argon gas is 10 sccm; and the bias
voltage of
direct current pulse is 60
volt below zero. When the CrN
transition layer and the Cr-Si-N plating layer are deposited, the flow of
nitrogen gas is used and positioned in a
light emission spectrum device on the near surface of the Cr target for carrying out the closed-
loop control so as to accurately modulate the compositions of the plating layer. The plating layer has the nanometer multilayered
amplitude modulation structure which in turn consists of a base layer, a Cr
interface layer, a CrN
transition layer and a Cr-Si-N
amplitude modulation structural layer with CrN and Si3N4 arranged outwards at intervals; the outermost layer is the Cr-Si-N amplitude modulation structural layer, wherein the amplitude modulation
wavelength of the Cr-Si-N amplitude modulation structural layer is less than 50 nanometers; the
hardness is larger than 20 GPa; the highest
hardness exceeds 20 GPa; and the Cr-Si-N amplitude modulation structural layer has excellent film-based binding strength (a scuffing method determines that the
critical load is larger than 85 newtons) and has
friction coefficient of less than 0.5 between WC balls. A plating layer material can be used for mechanical parts under the condition of high-load service and cutters.