A process for overlay plating on stell backed aluminium alloy bimetallic bearing strips

摘要

This invention relates to a process for overlay plating of steel backed aluminum alloy bimetallic bearing strips. Steel backed aluminum alloy strips are cleaned and first a very smooth zine nickel is deposited from a solution containing nickel sulphate, zinc oxide tartaric oxide and sodium hydroxide nickel plating in a nickel sulphamate bath having 14gm/litre nickel ions, then plating 25 microns of lead-tin-copper alloy from flu borate type plating from fluborate type bath containing 35 to 40gm/litre of stannous tin; finally plated bearings are rinsed and heat treated at 100 to 120˚ Celsius for 1 hour.