Chemical composition and selected mechanical properties of Al–Zn alloy modified in plasma conditions by RF CVD

• Published in: Applied surface science 2014-08, Vol.311, p.33-39
• Main Authors: Kyzioł, Karol, Kluska, Stanisława, Januś, Marta, Środa, Marcin, Jastrzębski, Witold, Kaczmarek, Łukasz
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Al–Zn alloys; Anti-wear coatings; Carbon; Chemical vapor deposition; Coatings; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Delaminating; Exact sciences and technology; Hardness; Mechanical properties; Physics; Plasma modification; Radio frequencies; SiCNH coating
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.04.193

The paper reports results of the study of surface composition and selected functional properties of 7075 (Al–Zn) alloys modified in Ar, N2, SiH4 and CH4 atmosphere at reduced pressure. RF CVD (Radio Frequency Chemical Vapour Deposition) technique was used in the study. The type or weight percentage of carbon in each modification varied in the resultant SiN:H and SiCN:H coatings. Alloy samples were treated with Ar+ plasma etching and N+ ion implantation at reduced pressure. The tests proved the values of selected mechanical properties (hardness ca. 10.5GPa, Young modulus ca. 95GPa) and adhesion (delamination force ca. 11.5mN) to be higher in the case of SiCN:H anti-wear coating (deposited in SiH4:CH4:N2=1:1:2 gas mixture) than the values of the respective parameters obtained in the remaining modifications. Further, carbon doped coatings (SiCN:H) exhibited significantly improved hardness (by about 50 to 70%) and nearly threefold increase in delamination force in comparison with SiCN:H coatings.