Author/Authors :
Correa، نويسنده , , E. and Zuleta، نويسنده , , A.A. and Sepْlveda، نويسنده , , M. and Guerra، نويسنده , , L. and Castaٌo، نويسنده , , J.G. and Echeverrيa، نويسنده , , F. and Liu، نويسنده , , H. and Skeldon، نويسنده , , P. and Thompson، نويسنده , , G.E.، نويسنده ,
Abstract :
Ni–B coatings have been deposited directly on commercial purity magnesium and AZ91D magnesium alloy by a chromium-free electroless process and characterized using scanning electron microscopy, glow discharge optical emission spectroscopy, gravimetric measurements and, for corrosion evaluation, hydrogen evolution. The surfaces of the coatings reveal a typical cauliflower-type appearance and form at a rate of ~ 8 to 13 μm/h. The nickel and boron contents of the coatings are relatively uniform across the whole thickness. The addition of NH4HF2 to the electroless bath improves the corrosion resistance provided by the coatings during immersion of coated substrates in sodium chloride solution.
Keywords :
Alloy , Ni–B , Electroless , Magnesium