Improvement of wear resistance of AZ91 magnesium alloy by electroless Ni-P coatings with influence of surfactant

Electroless Nickel-Phosphorus (ENi-P) coating is well-known in surface engineering techniques and is preferred in various mechanical, chemical and electronic industries view its extraordinary resistance to wear and corrosion. The paper summarizes the effect of surfactant on mechanical properties of electroless Ni-P alloy coating obtained from acidic bath. Morphology of the resultant coating was studied using scanning electron microscope and its phosphorus content was measured by EDX analyzer. Wear resistance of the coating, with and without surfactant, was evaluated by pin-on-disc tribometer wear tester machine. Endeavour of this study is to analyze the influence of Ammonium Lauryl Sulfate (ALS) surfactant on the microstructure and surface properties of ENi-P deposit on AZ91 Mg alloy substrate. The results revealed that there was a significant improvement in the wear resistance of the coated surface by addition of ALS surfactant in the chemical bath. ALS surfactant is distinctively added into the bath to reduce the surface tension forces, which binds the nickel particles to the hydrogen gas bubbles generated during the deposition process. The complete experimental details, results obtained and their analyses are presented in this paper. (C) 2017 Elsevier Ltd. All rights reserved.