METHOD OF MAKING MULTI-FUNCTIONAL NICKEL-BORON COAT Russian patent published in 2006 - IPC C25D3/56 

FIELD: electrodeposition; electrochemical deposition of nickel coats; making multi-functional solid corrosion-, heat- and wear-resistant coats, as well as protective and decorative coats.

SUBSTANCE: proposed method includes electrochemical deposition at current density of 0.5-5.0 A/dm² and temperature of 30-60°C from electrolyte at pH of 2.5-5.5 containing 250-400 g/l of nickel heptasulfate, 20-60 g/l of nickel hexadichloride, 30-60 of boric acid, 0.01-2.0 g/l of luster-forming additives; prior to electrochemical deposition of coat, borating additive belonging to inorganic or organic boron hydrides and their salts is introduced into electrolyte. Proposed method makes it possible to obtain non-porous coats meeting the high requirements pertaining to corrosion resistance, hardness and heat and wear resistance at large thickness (up to 0.25 mm) and retained preset properties over entire thickness; proposed method makes it possible to control physico-mechanical and chemical properties of coat enhancing stability of application process due to facilitated correction of electrolyte according to borating additive. Proposed method reduces the time required for attaining working modes.

EFFECT: increased yield of finished product at preset physico-mechanical and chemical properties; smooth distribution of boron in crystal lattice of nickel being deposited.

2 cl, 4 ex