Control of Deposition Parameters and Characterization of the Mechanical Performance Of Electrodeposited Cobalt Tungsten Alloys

These have been produced using hexavalent chrome plating baths, which is carcinogenic and the use is controlled. Several alloys, and methods of production have been put forward as potential replacements such as cemented carbides deposited by thermal spray.

One of the alloy systems that has been researched is electrodeposited cobalt tungsten, which forms a nano-structured coating from a gluconate bath.</p><p dir="ltr">The cobalt tungsten alloys tested in this thesis have been produced from a gluconate bath, operated at 80 ᵒC with air agitation and a deposition current density of 2.7 Adm-2.</p><p dir="ltr">The improvement of the as deposited mechanical properties of the electrodeposited cobalt tungsten structures has been investigated by the use of conventional heat treatments which leads to the formation of Co3W, and this in turn causes through cracking of the coating which reduces the effectiveness of the corrosion protection offered.</p><p dir="ltr">This work aimed to characterise the effect of deep cryogenic treatment on electrodeposited Cobalt tungsten coatings, by treated a range of compositions and varied growth directions.