The effects of deposition parameters on surface morphology and crystallographic orientation of electroless Ni-B coatings

Electroless Ni-B coatings were deposited on AISI 304 stainless steels by electroless deposition method, which was performed for nine different test conditions at various levels of temperature, concentration of NaBH₄, concentration of NiCl₂, and time, using the Taguchi L₉(3⁴) experimental method. The effects of deposition parameters on the crystallographic orientation of electroless Ni-B coatings were investigated using SEM and XRD equipment. SEM analysis revealed that the Ni-B coatings developed six types (pea-like, maize-like, primary nodular, blackberry-like or grapes-like, broccoli-like, and cauliflower-like) of morphological structures depending on the deposition parameters. XRD results also showed that these structures exhibited different levels of amorphous character. The concentration of NaBH₄ had the most dominant effect on the morphological and crystallographic development of electroless Ni-B coatings.