Effect of glycine as a complex agent on the surface and corrosion properties of Ni-P and Ni-P/Al₂O₃ electroless coating

Abstract

Purpose The ability to produce a uniform composition, high corrosion resistance with a hard coating layer during the electroless coating techniques are mainly based on the plating bath composition. The complexing agent is one of the most important components that control the coating layer properties. This paper aims to investigate the effect of the glycine as a complex agent on the surface and corrosion properties of Ni-P and Ni-P/Al2O3 electroless coating. Design/methodology/approach In this study, the effect of glycine as a complexing agent on the final surface and corrosion properties of the Ni-P and Ni-P/Al2O3 coatings has been investigated. The surface morphology and composition of the coated samples were investigated by scanning electron microscope (SEM) imaging and energy dispersive x-ray spectroscopy (EDS) analysis. Linear polarization scan and electrochemical impedance spectroscopy techniques were used to investigate the corrosion properties of the coating layer. Findings The results clarify that, glycine has a remarkable effect on the porosity content of Ni-P and Ni-P/Al2O3. It was found that increasing of glycine concentration results in higher porosity content in the coating layers. Also, the porosity in the coating layers minimizes the protectability of the coating against corrosion. The results also show that adding nano-alumina (Al2O3) to the coating path has improved the corrosion properties by decreasing the porosity in the coating layer. The scanning electron microscope (SEM) images showed that the concentration of glycine affects the content and distribution of alumina nanoparticles embedded in the coating layer. Also, it was observed that using a high concentration of glycine (0.4 M glycine), the alumina tends to agglomerate and the final alumina content in the coating was decreased. Originality/value The present study reveals that the quality of the final coating plays a major role in the corrosion performance of the steel substrate. The coating quality can by improve remarkably by optimization of the complexing agent used in the plating bath, to minimize the porosity involve in the coating layer.

Electroless Metallization of the Elements: Survey and Progress

“…Nickel can be deposited via conventional EL (vide infra) and galvanic 26,212,221,310−315 methods, though in the latter case Ni more often functions as a sacrificial substrate for replacement by other metals than the deposited metal. 35,163,307,309,316−322 323,324,326,330,331,336 to neutral 333,334 and to alkaline. 325,327,328,332,338,339,341−345 Levels of incorporated P or B generally depend upon bath pH and composition, with higher levels of incorporated P and B yielding increasingly amorphous deposits.…”

“…The preparation of composites to enhance EL Ni properties such as wear-resistance, hardness, corrosion protection, and catalytic properties via the use of particulate additives such as metal oxides, 41,216,369 metal sulfides, 370 silica, 74 alumina, 331,371 diamond, 372 nitrides, 327,373 carbides, 374−376 graphene oxide, 326 or polymers 74,377 has been a long-standing area of interest that has continued in recent years. Extensive reviews are available for readers interested in additional information.…”

“…Nickel can be deposited via conventional EL ( vide infra ) and galvanic ,,,− methods, though in the latter case Ni more often functions as a sacrificial substrate for replacement by other metals than the deposited metal. ,,,,− Conventional EL Ni depositions utilize baths containing H 2 PO 2 – , − amine boranes, ,− BH 4 – , − or to a lesser extent, N 2 H 4 , − as reducing agents. Baths containing H 2 PO 2 – deposit the metal as NiP alloys, whereas those containing amine boranes or BH 4 – yield NiB alloys and those containing N 2 H 4 deposit Ni metal.…”

“…Baths containing H 2 PO 2 – deposit the metal as NiP alloys, whereas those containing amine boranes or BH 4 – yield NiB alloys and those containing N 2 H 4 deposit Ni metal. Bath pH can range from modestly acidic ,,,,, to neutral , and to alkaline. ,,,,,,− Levels of incorporated P or B generally depend upon bath pH and composition, with higher levels of incorporated P and B yielding increasingly amorphous deposits.…”

“…The preparation of composites to enhance EL Ni properties such as wear-resistance, hardness, corrosion protection, and catalytic properties via the use of particulate additives such as metal oxides, ,, metal sulfides, silica, alumina, , diamond, nitrides, , carbides, − graphene oxide, or polymers , has been a long-standing area of interest that has continued in recent years. Extensive reviews are available for readers interested in additional information. ,,,, Here we present examples that reflect the recent developments in “smart” composites, i.e ., composites capable of responding to a stimulus to enable a desirable outcome or function.…”