tailieunhanh - Thickness determination and control of functional Ni–composite electrodeposited coatings

Surface electrochemically plated with nickel and highly inert particles provides useful applications: Ni–CeO2 as chemical catalysts, high hardness Ni–CBN (cubic boron nitride) as grinding tools, among others. The plating’s inert particles – 100 μm in size – on nickel surface need to be tightly adherent and evenly dispersed; it is therefore necessary to determine and control the coating layer’s thickness corresponding to the inert particles’ size by parameters like electrical current density and time. | Journal of Science and Technology 55 (1B) (2017) 1–6 THICKNESS DETERMINATION AND CONTROL OF FUNCTIONAL Ni–COMPOSITE ELECTRODEPOSITED COATINGS Nguyen Duc Hung1, *, Tran Thi Van Nga2, Mai Van Phuoc1 1 Institute for Chemistry and Materials 17 Hoang Sam Street, Nghia Do Ward, Cau Giay District, Hanoi, Vietnam 2 Faculty of Mechanical Engineering, University of Transport and Communications, 3 Cau Giay Street, Lang Thuong Ward, Dong Da District, Hanoi, Vietnam * Email: nguyenduchung1946@ Received: 30 December 2016; Accepted for publication: 26 February 2017 ABSTRACT Surface electrochemically plated with nickel and highly inert particles provides useful applications: Ni–CeO2 as chemical catalysts, high hardness Ni–CBN (cubic boron nitride) as grinding tools, among others. The plating’s inert particles – 100 μm in size – on nickel surface need to be tightly adherent and evenly dispersed; it is therefore necessary to determine and control the coating layer’s thickness corresponding to the inert particles’ size by parameters like electrical current density and time. With 40–60 nm CeO2 particle size, Ni plating thickness is 12 μm. With 60–100 μm CBN particles, Ni plating thickness is up to 60 μm. Weight and plating thickness were determined by the weight method and Faraday's law. The difference between the two methods showed the presence of inert functional particles on composite coating. EDX method and SEM image also showed the alignment as well as the distribution of particles on the coating surface. Catalytic ability of Ni–CeO2 coating and abrasive properties of Ni–CBN coating were tested by special methods, proving composite plating method useful as catalyst sand grinding metal surface. Keywords: Ni–composite coating, Ni–CeO2, Ni–CBN, catalytic surface, grinding properties. Ni composite coatings with non–conductive particles such as SiO2 [1], TiO2 [2, 3], Al2O3 [4], CeO2 [5], SiC [6, 7], or CBN [8] give coatings special properties, such as .