Investigation of graded Ni–Cu–P–PTFE composite coatings with antiscaling properties

Water scale on heat transfer surfaces is an important problem during heat transfer to water. In this paper, a graded electroless Ni–Cu–P–PTFE composite coating with non-stick and corrosion-resistant properties was applied to reduce the formation of CaSO4 deposits on the heat transfer surfaces. The effects of the concentrations of Cu2þ, cationic surfactant and PTFE in the plating solution on the coating rate and the PTFE content in the coatings were investigated. The thickness and the compositions of the coatings were measured using a digital micrometer and an energy dispersive X-ray microanalysis (EDX), respectively. Surface morphology of the coatings was analysed by a scanning electron microscope (SEM). The experimental results showed that the Ni–Cu–P–PTFE coatings inhibited the formation of CaSO4 scale on the heat transfer surfaces significantly. # 2004 Elsevier B.V. All rights reserved.