Two-step sintering and mechanical properties measurements of silicon carbide ceramics

• Grant number: 17/26754-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2018
• End date: March 31, 2019
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Sebastião Ribeiro
• Grantee: Douglas Siqueira Bernardo
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

Silicon carbide is a low-density ceramic with good physical, chemical and thermal properties, used in the aerospace industry and in power generation industries on account of its good resistance in extreme conditions. It is generally sintered together with metal oxides due to its low self-diffusivity which hinders its densification. However, even using additives, the density and grain size of the material produced by traditional sintering does not reach satisfactory levels. There are currently more sophisticated methods to achieve improvements in the properties of this material, but they are more expensive methods and require specific equipments. Two-step sintering is a lower cost method that has shown good results for different types of ceramics, with inhibition of grain growth and increased densification of the material. The objective of this project is to perform two-step sintering of the silicon carbide using three different additive systems: aluminum oxide and yttrium oxide; aluminum oxide and ytterbium oxide; aluminum oxide and dysprosium oxide; aiming to increase its density and produce finer microstructure than the normal, sintered in a single stage. The work will be carried out in the Department of Materials Engineering of the School of Engineering of Lorena, together with Prof. Dr. Sebastião Ribeiro, who has led many studies on this material. (AU)