Metalliding as an Electrochemical Process.
Abstract
Controlled electrolysis in molten salts can improve the surface properties of metal alloys for wear and corrosion resistance. Surfaces of aluminum 1100 and carbon steel were modified by passage of cathodic current under potentiostatic and galvanostatic control in molten salts variously containing Cerium (3+), Boron tetrafluoride (-), Titanium (3+) ions. Hard, poorly adherent Ceric aluminide and Cerous aluminide layers formed on Al surfaces at potentials which were some 200 to 400 mV positive to the reduction potential of Ce. The deposition occurred by a reductive precipiation mechanism from a KCl/LiCl melt at 560 C containing 1 mole% Ce(3+). Boride and titanide layers were formed on steel in a LiF/KF melt containing the respective ions. A borided layer on steel exhibited a factor of ten improvement in hardness and a titanided layer exhibited a 30% increase in hardness. While the borided steel showed only marginal improvement over the substrate in resistance to corrosion in neutral aerated 0.5M Sodium Chloride, the titanided steel showed a significant improvement in corrosion resistance under these conditions. Keywords: molten salts, aluminum, carbon steel, titanide wear, ceride, boride.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1987
- Accession Number
- ADA178744
Entities
People
- D. O. Raleigh
- M. W. Kendig