Investigation of the physical and mechanical properties of Ni–P and Ni–P–PTFE nanocomposite coatings deposited on aluminum alloy 7023

Abstract

In this study, various properties of NiP and NiP -PTFE coating fabricated by electroless process were investigated. These coatings were applied on aircraft-grade aluminum samples. The results showed that the addition of nano-PTFE particles decreases coating rate from 7.1 mm/h to 6.1 mm/h and hardness from 510 HV to 200 HV. Also by increasing the pH value, coating rate increases from 1 mm/h to 7 mm/h. Increasing the solution temperature from 75 C to 90 C also increases the hardness of coating from 125 HV to 210 HV. The results showed that the heat treatment at 300 C for 4 h increases the hardness up to 375 HV due to formation of Ni 3 P hard phase in NiP -PTFE coating. Addition of PTFE particles have improved tribological properties due to its lubricating effects and simultaneously, have reduced corrosion resistance compared to NiP coatings, so that the corrosion current for Al, NiP , and NiP -PTFE coatings is À880, À550, and À770 mA/cm 2 , respectively.

Preparation of a Ni-P-nanoPTFE Composite Coating on the Surface of GCr15 Steel for Spinning Rings via a Defoamer and Transition Layer and Its Wear and Corrosion Resistance

“…Additionally, the Ni-P-nanoPTFE composite coating, deposited after being incorporated into the coating, has self-lubricating properties. Many researchers have successfully prepared Ni-P-nanoPTFE composite coatings on metals and nonmetals and studied the effects of plating solution components, process parameters, dispersion methods, and PTFE content on the wear and corrosion resistance of the coatings [ 19 , 20 , 21 ]. The recent research mainly focuses on the performance of combining Ni-P-nanoPTFE composite coatings with other coatings [ 22 ] or how to increase the PTFE particle content in Ni-P-nanoPTFE composite coatings on substrates in a short time [ 23 ]; however, the research on how to ensure the uniform dispersion of nano-PTFE particles in Ni-P-nanoPTFE composite coatings and reduce the occurrence of missing plating is not perfect.…”

The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

“…The surface energy range of 22 to 28 mN/m can be achieved through the Ni metal properties with the low surface energy of PTFE [15]. The material becomes hydrophobic (as low surface energy limits wettability), offering minimal microbial and anti-scaling properties, decreasing the likelihood of scaling [14] and corrosion [16]. Since PTFE has cryogenic properties and a relatively high melting point compared to the other polymers, ENP+PTFE composite coatings were applied and used in heating and cooling systems up to 290 • C [3].…”

“…Since PTFE has cryogenic properties and a relatively high melting point compared to the other polymers, ENP+PTFE composite coatings were applied and used in heating and cooling systems up to 290 • C [3]. Besides improved thermal conductivity [17], it also has a lower friction and energy wear rate [16,18], therefore, it could be used in areas of wear from high speeds but low contact loads or in the presence of abrasive materials such as silica scales. This indicates the composite coating could potentially provide protection in boilers, separators, condensers, and safety and pumping systems in geothermal plants.…”

Axisymmetric radiative titanium dioxide magnetic nanofluid flow on a stretching cylinder with homogeneous/heterogeneous reactions in Darcy-Forchheimer porous media: Intelligent nanocoating simulation

“…Subsequently the methodology reported by Das et al [20] was implemented in many diverse areas of smart coating technology over the past decade or so. These include hydrophobic nanostructured plasma-polymerized intelligent magnetized coatings [21], Nickel-cobalt-silicon carbide electroconductive coatings with enhanced wear properties in manufacturing engineering [22], Nickel-phosphorus and PTFE hybrid magnetic coatings for metallic component surface finishing [23] and titanium-aluminium-vanadium magnetic nanofluid lubricants for surface grinding heat control. Various formulations for simulating nanofluid transport have been developed, notably by Buongiorno [26] at MIT, Koo [27] and Li [28] at North Carolina State University, USA and Tiwari and Das [29] at the Indian Institute of Technology.…”