Keynote Speakers

Prof. Dr. Mikhail Zheludkevich,
Head of Department,
Corrosion and Surface Technology,
Institute of Materials Research,
Helmholtz-Zentrum Geesthacht (HZG),
Max-Planck Str. 1, 21502 Geesthacht, Germany

Abstract

Active protective multi-functional coatings based on "smart" nanocontainers

The destructive effect of environment and the corrosion induced degradation are them portent problems which determine the service life of many metallic components. The application of organic coatings is the most common and cost effective method of improving protection and durability of metallic structures. However the degradation processes develop faster after disruption of the protective barrier. Therefore an active protection based on “self-healing” of defects in coatings is necessary to provide long-term effect.
The present paper overviews our recent progress in development of novel protective coatings with self-healing ability on the basis of nanocontainers that release entrapped corrosion inhibitor in response to presence of corrosive species. The new nano containers for organic and in organic corrosion inhibitors were developed in this work employing nano carriers including poly electrolyte layer by layer assembled structures, mesoporous nanoparticles, halloysite nanotubes and different nanoclays. The combination of different nanocontainers in the same coating system was demonstrated to provide an important cooperative effect especially when active coatings for hybrid assemblies are considered.

Dr. U. Kamachi Mudali, Associate Director, IGCAR, Kalpakkam

Dr. Ir Véronique Vitry,
Department of Metallurgy,
Faculty of Engineering,
University of Mons,
Belgium.

Abstract

Methods to enhance electroless nickel-boron coatings

Electroless nickel-boron coatings provide a good alternative to hard chrome plating with their high hardness (up to 800 hv100) and their excellent shape compliance and adhesion. The usual plating rate of borohydride-reduced coatings is 15µm/h but the operating temperature is very high 95°C. Several methods can be used to optimize the properties of the coatings or the plating process. First, heat treatment can bring about an important increase of hardness, wear and abrasion resistance with only a slight decrease in corrosion resistance. In cases where very high hardness is required, vacuum nitriding can be used to reach values up to 1600hk100 without loss of adhesion.
In terms of deposition process, it is possible to increase the plating rate while slightly decreasing the plating temperature by the use of ultrasound assistance. Using this method, plating rate in the range of 20µm/h can be reached for temperatures in the 85-95°C range, thus increasing productivity, without significant modification of the coating properties.
Electroless nickel-boron, in the as-plated state but also in the enhanced state will be compared in terms of properties to hard chrome, but also to other alternatives such as electroless nickel-phosphorous and cold-sprayed coatings.