Accession Number:

ADA273411

Title:

Electrochemical Behavior of Ion-Plated TiN and Cu-Cr Coatings

Descriptive Note:

Final rept.

Corporate Author:

CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL ENERGY AND UTILITIES SYSTEMS DIV

Personal Author(s):

Report Date:

1993-09-01

Pagination or Media Count:

41.0

Abstract:

The electrochemical corrosion behaviors of titanium nitride TiN and metastable copper-chromium Cu-Cr alloy coatings grown on glass, aluminum, and copper substrates using a plasma-assisted physical vapor deposition ion- plating technique were investigated. Various polarization techniques were used for corrosion tests in oxygen-saturated and deaerated 5 percent Na2SO4 and 3.5 percent NaCl solutions of two different acidities pH--6 and 3. The structure, chemistry, and morphology of the coating surfaces before and after corrosion testing were analyzed with scanning electron microscope, x-ray diffraction, Auger, and x-ray photoelectron spectroscopic techniques. Titanium nitride coatings are chemically passive but do not provide effective protection for metallic substrates, under conditions involving pitting corrosion, due to the presence of pinholes in the as-deposited TiN coatings. The inherent properties of TiN do appear suitable for electromagnetic interferenceelectromagnetic pulse shield applications provided the problem of film defects porosity, pinholes can be solved or if the substrate type and corrosion conditions are such that passivation of the substrate surface occurs. Cu-Cr alloy coatings show a general corrosion behavior, with corrosion rates of a few mils per year at the free corrosion potential, which is unsatisfactory for a thin film coating application. Electromagnetic shielding, Cu-Cr Coatings, Coatings, Corrosion resistance, TiN Coatings.

Subject Categories:

  • Physical Chemistry
  • Coatings, Colorants and Finishes
  • Electricity and Magnetism
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE