Effect of etching conditions on electroless Ni-P plating of 3D printed polylactic acid

Abstract

ABSTRACT The aim of this study is to investigate the effect of the etching conditions on some technologically important properties of the Ni-P coating deposited by an electroless process on 3D printed PLA and PLA-flex. The influences of the temperature and the concentration of the etching sodium hydroxide solution on the deposition rate, composition, adhesion, wetting and roughness of Ni-P coatings were determined. The studies revealed that the high temperature and concentration of the etching solution did not improve the coating properties. In regard to the wetting and adhesion properties of the Ni-P coating, the best results were obtained at concentrations of the etching solution from 100 to 200 g L−1 NaOH and at a temperature of 20–40°C. These conditions allow good wetting of the freshly deposited nickel. Etching plays an important role not only in improving adhesion, but also has an effect on the composition and thickness of the nickel layer.