Electroless Ni-B coatings: controlling factors of carbon in Its compositions

Abstract

The concept of electroless coating, a method of depositing a metal or alloy onto a substrate through a chemical reduction process without the use of an external power source. Electroless coating, a crucial technology in the field of surface engineering, offers uniform coating thickness, offers good corrosion resistance and excellent tribological properties. This M. Tech project research explores the study of electroless coatings fabricated on the low carbon steel substrates reduced by using sodium borohydride as reducing agent. Deposition process and the bath compositions conditions affect various factors influencing the composition of electroless coatings, aiming to optimize their properties for diverse industrial applications. The study systematically investigates the impact of key parameters, including temperature, pH, concentration of reactants, deposition time, and agitation, on the deposition rate and quality of the coatings. Through a combination of experimental methods and analytical techniques, this thesis identifies optimal conditions for achieving desired coating characteristics. The findings provide a comprehensive understanding of how these controlling factors interact, facilitating more precise control over the electroless coating process. This research not only contributes to the theoretical knowledge in the field but also offers practical guidelines for industrial applications, enhancing the performance and reliability of electroless coatings. The bath composition controlling the compositions of electroless Ni-B coatings has rarely been studied. In this project, attempts were made to study the composition of Ni-B coatings deposited in the electroless route and relate that to the composition of the bath solution in various stages. Before going to the mechanical and tribological tests, the electroless Ni-B coatings are thoroughly characterized using field emission scanning electron microscopy (FESEM), XRD analysis (X-ray Diffraction), Energy dispersive X-ray spectroscopy (EDS) and Inductive coupled plasma atomic emission spectroscopy (ICP-AES) by assessing the structural, compositional, and morphological features of the coatings. Furthermore, mechanical and tribological tests were done to understand the coatings behavior deposited with different factors.