Characterization and corrosion properties of electrodeposited Ni-W alloys

摘要

Ni-W alloys electrodeposited for citrate solution consist of three different phases, which are all present in high W-content alloys: a solid solution of W in a Ni matrix; an intermetallic compound Ni_4W, as well as another solid solution of W in Ni with a W content higher than 20 mol. /100. XPS analysis revealed that the alloys were covered with a surface layer of complex structure containing the pure metals Ni and W, Ni(OH)_2 and WO_3, on the very surface as well as some partially reduced oxide WO_2.72 (most probably a solid solution of WO_2.72 in Ni) and tungesten carbide in the layer underneath.