Microstructures of Ni-AlN composite coatings prepared by pulse electrodeposition technology

► PED was used to prepare composite coatings on steel substrates surface. ► Effect of pulse current on the nucleation and growth of grains was investigated. ► Composite coatings consisting of crystalline Ni and AlN particles were fabricated by PED. ► Ni-AlN composite coatings by PED showed more compact surfaces and less grain sizes than by electrodepositing.