Browsing by Keyword "Adhesion"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Investigation of particle flattening behaviour and bonding mechanisms of APS sprayed coatings on magnesium alloys(2007-02-04) Parco, Maria; Zhao, Lidong; Zwick, Jochen; Bobzin, Kirsten; Lugscheider, Erich; EXTREMATMagnesium alloys are promising alternatives to other lightweight materials due to their high specific strength and stiffness. However, the use of magnesium alloys is limited by their poor wear behaviour and low corrosion resistance for many industrial applications. The thermal spray technology offers a wide range of possibilities to improve the surface properties of Mg-based components. In this study, three different coating materials, namely Al, NiAl5 and Al2O3, were applied on AZ91 and AE42 substrates using the atmospheric plasma spray technology. The investigation was focused on the bonding strength of the coatings and the related bonding mechanisms. For a better understanding of the bonding mechanisms, the flattening behaviour of the spray particles was investigated in correlation with the substrate pre-heating temperature. It was found that NiAl5-particles could well melt the substrate at the surface and deformed it locally; Al-particles did the same but to a lower extent. The dominating bonding mechanism for NiAl5-coatings could be attributed to a metallurgical bonding. For Al-coatings, this mechanism played a more important role once the substrate pre-heating temperature was increased. Al2O3 particles in contrast, were less able to deform the substrate in spite of their higher thermal load and the mechanical anchoring remained the main bonding mechanism. The thermo physical properties of the Mg substrate showed also to have an influence on the adhesion of the coatings.Item Surface energy and frictional / adhesive properties of polymeric resist films(2011) Koszewski, A.; Jarzabek, D.; Rymuza, Z.; Obieta, I.; Tecnalia Research & InnovationThe effect of plasma treatment on surface properties of resist films devoted for nanoimprint lithography (NIL) was studied. The Atomic Force Microscope was used to identify surface topography, pull-off force and lateral (friction ) force of the resist film before and after plasma treatment with the presence of nitrogen and hydrogen gases. The wettability was studied to estimate surface energy of the films both with polar and dispersion components. The AFM-based microtribometer enabled to study the frictional behavior of the resist films. The results of these extended studies have shown that the used plasma functionalization is effective to modify dramatically the surface properties of the resist films.Item The use of preliminary ion implantation and heating on the substrate for modifying TiN coating properties and TiN/substrate interface(2001-07) Solodukhin, I. A.; Khodasevich, V. V.; Uglov, V. V.; Brizuela, M.; Oate, J. I.; INGENIERÍA DE SUPERFICIES; Tecnalia Research & InnovationThe influence of preliminary implantation of argon ions on a carbon steel substrate and deposition temperature on the texture and adhesion of TiN coatings deposited by cathodic arc plasma deposition has been investigated. The samples have been evaluated by glancing X-ray diffraction, Auger-electron spectroscopy and scratch adhesion testing. Strengthening of the (220) TiN texture with increasing ion implantation dose on the substrate has been revealed. An increment of deposition temperature (from 450 up to 720 K) leads to a more chaotic orientation of TiN crystallites. An increase of transitional layer thickness (by 60% for the Ti profile) is only observed when depositing the coating at high temperature (720 K). However, both the preliminary implantation process and the heating of the substrate lead to an adhesion improvement of TiN coatings.