Internal stress in electro- and electroless deposited coatings
报告题目：Internal stress in electro- and electroless deposited coatings
报 告 人：Prof. Armyanov
Institute of Physical Chemistry, Bulgarian Academy of Sciences (IPC BAS)
There is increased interest in internal stress (IS) today because it affects some of the most important protective, mechanical and physical properties of deposits, (e.g., corrosion resistance, wear, adhesion, fatigue strength, toughness and magnetic behaviour). To characterize the strained state of the coating more accurately, it is necessary to determine not only the average stress within it, but also the residual stress distribution through its thickness. Accurate characterization of the strained state of the coating will be presented using three types of the (IS): instantaneous, residual and average. Three possible phenomena causing the post-plating change of IS are considered: desorption of hydrogen, which is included during the plating; stress relaxation; and mismatch in thermal expansion coefficients of substrate and coating. The stress relaxation in metallic glasses will be considered and useful approach to its characterisation will be presented. Some examples for evaluation of IS for industry will be considered. 报告人简介：
Dr. Sc. Stephan Atanassov Armyanov is Emeritus Professor at the Institute of Physical Chemistry, Bulgarian Academy of Sciences (IPC BAS). The research interests of S. Armyanov include the relations between deposition conditions, structure and properties of electroless and electrodeposited materials and their properties connected with special applications: magnetic behavior, internal stress, thermal stability of amorphous state, photo-catalytical activity, core-shell nano-catalysts for fuel cells. S. Armyanov has authored and co-authored over 150 papers and reports. He is holder of 5 patents (including for thin film memory disks) and one European patent. S. Armyanov presented his results at 60 conferences some of them invited (including two times at the Gordon conference) in many countries.