Effect of TMAB concentration on structural, mechanical and corrosion properties of electrodeposited Ni-B alloys

The influence of trimethylamine borane (TMAB) concentration as a boron (B) source on the structural and corrosive properties of Ni-B alloy coatings produced by electrodeposition was investigated. The crystal structure of the Ni-B coatings is influenced by the B content in the coating, having a slight (220) preferred orientation. The B content in the coating increased from 16 to 34 at.% with the corresponding increase in the concentration of TMAB from 1 to 20 g/L, while interestingly retaining a crystal structure. The hardness of the coatings increased with increasing B content owing to the formation of smaller crystallites. An increase in B content in the alloy coatings, led to a shift in the Ecorr values to more anodic potentials, indicating increase corrosion protection for the Ni-B coatings. This study achieved to reach 34 at.% B content in Ni-B alloy coatings produced by electrodeposition while preventing amorphization of the coating layer.