The Effect of Oxide Dissolution on the Electrodepositing of Dispersion‐Hardened Co and Ni ‐ Al2 O 3 Alloys

Abstract

The solubilities of γ‐ and α‐Al2O3 particles have been investigated in dilute H2SO4 and in watts‐type plating electrolytes of cobalt and nickel. The effects of the presence of Al3+ ions in the plating solutions on the properties of electrodeposits of cobalt and nickel have also been studied. The results show that γ‐oxide is more soluble than α‐oxide, the solubility increases with decreasing solution pH and increasing temperature. Aluminum contents of up to 0.04 weight per cent (w/o) in cobalt and 0.02 w/o in nickel were found and the room temperature yield strength values increased to about 40% for cobalt and 20% for nickel deposits. The effects on the yield strength values of normalCo‐Al2O3 and normalNi‐Al2O3 alloys due to the presence of Al3+ ions in their respective plating electrolyte‐oxide suspensions are also discussed.

Electrodeposition of Cobalt Using an Insoluble Anode

“…However, secondary cells using zinc negatives have a poor cycle life (100-400 cycles) (1). This is due mainly to the failure of the zinc electrodes (1,2). If the cycle life of the zinc electrode can be extended, zinc-silver oxide cells would be much more valuable in aerospace and other applications where the high energy density justifies…”

“…The electrodeposition of cobalt, dispersion-hardened cobalt, and cobalt-based alloys has been the subject of investigation (1)(2)(3)(4)(5)(6) at this laboratory for many years because of the potential application as protective coatings to improve the wear and erosion characteristics of the substrates. In conventional cobalt plating, soluble anodes are used to replenish the metal deposited at the cathode.…”