Electrodeposited Ni–Al composite coatings with high Al content by sediment co-deposition

Sediment co-deposition (SCD) was adopted to develop Ni–Al particle composite coatings. The SCD Ni–Al particle composite coatings have much higher volume fraction of Al particles in coatings with low particle loading in bath than the conventional electrodeposited (CED) Ni–Al composites. 30–35 vol% of Al particles was incorporated in composite coatings at a particle loading as low as 40 g/l. It was found that the volume fraction of Al particles in composite coatings was strongly affected by particle loading up to 40 g/l, but is independent of current density and Off/On time of stirring. The Guglielmi model is employed to explain the effects of deposition parameters. The diffusion treatment of as-plated composite coatings was performed at various temperatures and times. Single-phase γ′-Ni3Al coating was formed after diffusion treatment.