Electroless nickel fabrication on surface modified magnesium substrates

Abstract

In recent years, magnesium (Mg) has evolved as a salient material, in affiliation with electroless nickel (Ni) coating, which have found applications in automobiles, aerospace and confederate fields attributing to its excellent inherent weight sensitive properties. However, being acknowledged for its remarkable auxiliary properties like flexible machining, appreciable weight sensitivity and ability to be patently die-cast into mesh constructs, magnesium is prejudiced by aeronautical standards predominantly for its inferior corrosion resistance properties. In this sense, electroless nickel plating on magnesium and its alloys has been suggested to extricate it from corrosion problem and make it more competitive in industrial and defence applications. Autocatalytic fixation of metal ions onto respective substrates accrues and alters their mechanical, electrochemical and tribological properties, destitute of any electric current aid. This proficiently identified technique is prosecuted with the assistance of a series of sequenced operations involving a prior pretreatment, which corresponds to the chemical cleaning of the substrate surface; electroless coating; and a later activation process which is a mild etching of the electroless coated surface. The susceptibility of magnesium to this methodology has advanced and propagated its exercise and applicability in aircraft, satellites and allied aeronautical fields. Contemporarily, researchers have proposed various eco-friendly and modified duplex and composite coatings which have transmuted properties of these appendages by tailoring alloy compositions and reagents employed. This review article systematically colligates various considerations and evaluations on electroless nickel applications of magnesium and its alloys and explicates how it anchors its practice in the respective domains. Furthermore, a comprehensive analysis is devised based on the pre-existing treatment methods for accomplishing the same. Keywords: Electroless nickel plating, Magnesium, Magnesium alloys, Corrosion-resistance, Micro arc oxidation (MAO)