Influence of plasmochemical modification of Al–Cu–Mg alloys on surface structure and functional properties

• RF CVD method was applied for surface modification of Al–Cu–Mg alloys.
• The second stage of the substrate aging in RF reactor was achieved.
• Improvement of hardness and anti-wear parameters after applied processes was achieved.
• SiCNH coating resulted in the most good tribological behavior on the Al–Cu–Mg alloys.

The article presents the results of the study of the composition and selected functional properties of Al–Cu–Mg alloys modified by RF CVD technique (Radio-Frequency Chemical Vapor Deposition). The type and composition of the deposited SiNH and carbon doped SiNH layers was altered in the experiments. The samples were pre-treated with argon plasma etching and N+ ion implantation.On the basis of the experimental evidence it is concluded that the deposition of an anti-wear SiCNH coating (using SiH4:CH4:N2 = 1:1:2 gas mixture) improves both the investigated mechanical properties (hardness ca. 10 GPa, Young modulus ca. 95 GPa) and tribological performance of the control (unmodified) alloy sample as well as those of the modified alloy samples whose outer layer is SiNH.