Accession Number : ADA140783

Title :   Thermally-Sprayed Active Metal Coatings for Corrosion Protection in Marine Environments.

Descriptive Note : Final rept.,

Corporate Author : STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Lieberman,E. S. ; Clayton,C. R. ; Herman,H.

Report Date : JAN 1984

Pagination or Media Count : 111

Abstract : In this investigation, coatings of zinc, aluminum, zinc-15 wt% aluminum (ZA) and duplex-layered coatings of aluminum and zinc were flame and electric-arc sprayed onto mild steel substrates and exposed to a variety of corrosive conditions in a 3.0 wt% sodium chloride solution and in natural sea water. The goal of this study has been to obtain performance criteria and quality assessment of these coatings and to ultimately understand their mechanisms of protection as well as failure. The coating systems were subjected to electrochemical, salt spray, immersion and adhesion tests. To reduce surface porosity, thereby increasing the mechanical integrity and corrosion protection, the sprayed coatings were also sealed with an epoxy polyamide. The ZA coatings exhibit strong corrosion protection, high adhesive strength and a high coating density. A duplex-layered coating of aluminum, sprayed onto zinc-coated steel, proves to be effective in reducing crevice attack of the aluminum coating. Studies on the microstructure of electric-arc-sprayed coatings of different wire diameters revealed that as the wire diameter is decreased, a more dense coating will arise due to better atomization.

Descriptors :   *Steel, *Substrates, *Metal coatings, *Flame spraying, *Protective coatings, Corrosion inhibition, Ocean environments, Mechanical properties, Cracks, Failure(Mechanics), Porosity, High strength, Sea water, Microstructure, Aluminum, Zinc, Adhesion, Epoxy compounds, Polyamide plastics, Naval research, Marine engineering

Subject Categories : Coatings, Colorants and Finishes
      Properties of Metals and Alloys
      Marine Engineering
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE