The Effects of Deposition Parameters on Surface Morphology and Crystallographic Orientation of Electroless Ni-B Coatings

摘要

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 NaBH_4, concentration of NiCl_2, and time, using the Taguchi L_9(3~4) 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 NaBH_4 had the most dominant effect on the morphological and crystallographic development of electroless Ni-B coatings.