Tyrosine as a novel potential stabilizer in an electroless Ni-P bath exempt of trisodium citrate as complexing agent: Chemical baths optimization and comparative study

Abstract

• New formulation of Ni-P alloy electroless plating baths using hypophosphite as reducing agent. • Abundance of trisodium citrate as the main component acting as a complexing agent in Ni-P electroless plating baths. • Addition of tyrosine as a complexing-stabilizing agent led to a significant improvement in bath stability accompanied by a deposition rate of 18 µm h −1 . • Optimization of the tyrosine-containing bath led to a gain of 67% NiSO4,6H2O and 85% CH 3 COONH 4 . The effect of tyrosine (C 9 H 11 NO 3 ) as a new stabilizing agent on the composition and conditions of the electroless plating bath of the Ni-P alloy was studied. A comparative study with trisodium citrate, which is commonly used, as a stabilizing complexing agent revealed the effect of tyrosine in this study. Scanning electron microscopy (SEM) and X-Ray Energy Dispersion (EDX) are used to study the properties of the Ni-P coating deposit developed in the presence of tyrosine and trisodium citrate. The result of this optimization showed that the use of tyrosine causes the concentration of NiSO 4 and CH 3 COONH 4 in the bath to decrease to 67% and 85%, respectively. In contrast, the use of trisodium citrate had no effect neither on the composition nor on the effect of the bath conditions of the deposit. In addition, the use of C 9 H 11 NO 3 as a stabilizing agent in the bath promotes the increase of the phosphorus content more than trisodium citrate when optimizing the accelerating agent in the bath and therefore changes the structure of the Ni-P deposits developed.