Microstructure and mechanical properties of Cr–Si–N coatings prepared by pulsed reactive dual magnetron sputtering

✍ Scribed by M. Benkahoul; P. Robin; S.C. Gujrathi; L. Martinu; J.E. Klemberg-Sapieha

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 429 KB
• Volume: 202
• Category: Article
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2008.02.014

✦ Synopsis

Cr-Si-N thin films were deposited by pulsed DC reactive dual-magnetron sputtering using Cr and Si targets, while various currents applied to the Si target allowed one to vary the Si content (C Si ) in the films. Microstructure, composition and mechanical properties were studied as a function of C Si using XRD, ERD-TOF and depth-sensing indentation. Three regions of C Si were distinguished: (i) C Si b 2.3 at.%, where the grain size (D) does not significantly change with increasing C Si ; (ii) 2.3 b C Si b 6.7 at.%, where D decreases as C Si increases; and (iii) 6.7 ≤ C Si ≤ 11.6 at. %, where a relatively rapid decrease of D is observed with increasing C Si . We found that the hardness (H) and the reduced Young's modulus (E r ) of the films reached maximum values of H ~24 GPa and E r ~240 GPa for C Si ~2.3 at.%. Based on the evolution of the microstructural and mechanical properties of the Cr-Si-N films, we propose to explain the hardening observed for C Si b 2.3 at.% in terms of the solid solution mechanism rather than the nanocomposite formation.