Production and characterization of quasicrystalline coatings for thermal barriers

• Grant number: 14/01854-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2014
• End date: July 31, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Walter José Botta Filho
• Grantee: Witor Wolf
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Thermal Barrier Coatings materials (TBC´s) are applied to protect metallic devices which work under high oxidation and wear conditions, due to the elevated working temperatures. TBC´s are traditionally fabricated with a metal/ceramic system where the metallic substrate (in general steel or a nickel alloy) is protected by a ceramic layer which promotes thermal insulation. In the present project it is proposed the study of quasicrystalline alloys as potential coating materials for this application, aiming to substitute the ceramic coatings and trying to decrease the effects of thermal tensions generated at the interface between the substrate and the coating materials due to large differences between the thermal expansion of the materials which the conventional TBC´s are made of. Specifically the system Al-Co-Fe-Cr which generates quasicrystalline phases will be used on the fabrication of the quasicrystalline TBC. The fabrication process of HVOF (High Velocity Oxigen Fuel) will be used to fabricate the coating. The Al-Co-Fe-Cr alloy and the coating will be characterized by x-ray diffraction (XRD), by scanning electron microscopy (SEM) and by transmission electron microscopy (TEM) to identify the phases in the material as well as to control the chemical composition. The quasicrystalline alloy will also be characterized mechanically with hardness and compression tests. Differential scanning calorimetry (DSC), dilatometry and thermal conductivity tests will be made in order to evaluate the thermal behavior of the alloy, which is important for TBC application. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

WOLF, W.; SCHULZ, R.; SAVOIE, S.; BOLFARINI, C.; KIMINAMI, C. S.; BOTTA, W. J.. Structural, mechanical and thermal characterization of an Al-Co-Fe-Cr alloy for wear and thermal barrier coating applications. SURFACE & COATINGS TECHNOLOGY, v. 319, p. 241-248, JUN 15 2017. (13/05987-8, 14/01854-6)

WOLF, W.; BOLFARINI, C.; KIMINAMI, C. S.; BOTTA, W. J.. Assessment of phase constitution on the Al-rich region of rapidly solidified Al-Co-Fe-Cr alloys. MATERIALS CHARACTERIZATION, v. 122, p. 76-82, DEC 2016. (13/05987-8, 14/01854-6)