Effect of Ni Interlayer on the Properties of Cr/Crn Coatings on 1010 Steel
Nickel thin films have been coated on the steel surface with electroless plating and sputter deposition. The deposition rates and thin film properties including crystal structures, microhardness, scratch resistance and cross section microstructures have been determined and compared. The deposition rate of electroless nickel followed a parabolic rate relationship with time whereas that of sputter deposited nickel was linear. For up to 1 µm coating thickness, the rate of electroless nickel is about ten times faster than that of sputter deposition under the experimental conditions of this study. The sputter deposited Ni shows better crystallinity and higher microhardness compared to electroless plated Ni, but superior adherence performance of electroless plating Ni is observed. The effect of electroless plating and sputter deposited Ni coatings (65nm) acting as an interlayer between the Cr/CrN overlayers and steel substrates on the properties of the Cr/CrN layers are investigated. No obvious influence of the Ni interlayer on the adhesion properties and microhardness of Cr/CrN coatings are observed. For the Cr/CrN coatings, adhesion properties and microhardness improved with increase of N 2 content in the sputter gas. IR heat treatment is helpful for the improvement of the microhardenss and adhesion properties of the Cr/CrN and Cr/CrN/Ni films. The IR heat treatment also improve the crystallinity of the Cr, CrN and Ni phases for the Cr/CrN/Ni coatings.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:ni interlayer cr gn coating sputter deposition mechanical property adhesion performance
Date of Publication:01/01/2002