Improved hardness and corrosion resistance of iron by Ti/TiN multilayer coating and plasma nitriding duplex treatment

• Published in: Surface & coatings technology 2010-06, Vol.204 (18), p.3082-3086
• Main Authors: Chen, Chang-Zi, Li, Qiang, Leng, Yong-Xiang, Chen, J.Y., Zhang, Peng-Cheng, Bai, Bin, Huang, Nan
• Format: Article
• Language: English
• Subjects: Adhesion; Applied sciences; Coating; Corrosion; Corrosion environments; Corrosion resistance; Cross-disciplinary physics: materials science; rheology; Deposition; Exact sciences and technology; Heat treatment; Ion nitriding; Iron; Magnetron sputtering; Materials science; Metals. Metallurgy; Multilayers; Nitriding; Nonmetallic coatings; Physics; Plasma immersion ion implantation; Plasma nitriding; Production techniques; Protective coatings; Surface treatment; Surface treatments; Thermochemical treatment and diffusion treatment; TiN; Titanium; Titanium nitride
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2010.03.017

A duplex treatment of plasma nitriding followed by deposition of a Ti/TiN multilayer coating was performed on commercial pure iron. Plasma nitriding was carried out using high frequency low bias voltage plasma immersion ion implantation (HLPIII), and the Ti/TiN multilayer films were deposited using unbalanced magnetron sputtering on the nitrided iron surface. The plasma nitriding layer was 4 μm thick, consisting of mainly ε-Fe 3N and γ-Fe 4N. The microhardness of the iron with Ti/TiN multilayer coating + plasma nitriding duplex treatment was over 18 GPa, somewhat harder than that of iron with a Ti/TiN multilayer film but without plasma nitriding, and almost 5 times that of the (only) nitrided iron. The film-cohesion for Ti/TiN multilayer film on the nitrided substrate was much better than that on the substrate without nitriding treatment. Comparing with the Ti/TiN film on bare iron, the samples with Ti/TiN multilayer coating + plasma nitriding duplex treatment have better corrosion resistance.