Structure and fatigue behavior of electroless plated Ni-Zn-P films using pretreatments, annealing and an applied magnetic field

Abstract

Electroless ternary Ni-Zn-P films are plated onto a low carbon steel substrate. The surface morphology, microstructure, hardness, fatigue life and corrosion properties of the Ni-Zn-P coatings are respectively determined using scanning electron microscopy, X-ray diffraction, nano-indentation, high-strain low-cycle fatigue and polarization tests. The substrates pretreated using the proposed roughening (15 % H2SO4, 20 min) and activation (10 % H2SO4, 1 min) produce good Ni-Zn-P film deposition. When the annealing temperature reaches 400 °C, the Ni–P-Zn films contain crystalline Ni, FeNi and a precipitation Ni3P structures phase. Applied magnetic field improves the film growth rate, mechanical properties and corrosion resistance.