Abstract
By combining lightweight metal alloys with ceramics, it is possible to adapt material properties on stressed parts and thus increase stiffness and/or change the thermal resistance: yet joining such materials is problematic due to the poor wettability of ceramics by molten metals. In this work, the technique of friction surfacing is used to connect alumina (Al2O3) with an aluminium alloy (EN-AW 5083). Despite the fact that Al2O3 has a relatively high coefficient of thermal expansion and a low thermal shock resistance, specimens have been produced showing encouraging results. In order to compensate for these material properties the substrate was preheated to a minimum of 150°C. In tests bonding strengths reached 47.8 MPa and coating thicknesses of 213 μm were achieved; results which are comparable with conventional thermally sprayed coatings. Bonding strengths were determined by using a pull-off adhesion tester and the coating thickness was measured with a laser scanning microscope. Analysis of the joint zone shows no clear evidence of chemical reactions (intermetallic compounds) or diffusion. Mechanical interlocking can only be shown to be accountable for 16% of the bonding strength with investigations turning towards van der Waals forces and their contribution to adhesion.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
