Processing and characterization of high strength wear resistant materials
| Grant number: | 10/51925-6 |
| Support type: | Regular Research Grants |
| Duration: | December 01, 2010 - May 31, 2013 |
| Field of knowledge: | Engineering - Materials and Metallurgical Engineering |
| Principal Investigator: | Sebastião Ribeiro |
| Grantee: | Sebastião Ribeiro |
| Home Institution: | Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil |
Abstract
Silicon carbide-based ceramics, SiC, are widely applied in engineering due to their excellent mechanical, thermal and chemical properties. To produce SiC ceramics with specific properties for each application requires selecting the processing method that will result in suitable micro structures. Therefore, these ceramics are normally sintered via liquid phase, using mixtures of aluminum and rare earth oxides, e.g., Al2O3/Y2O3, Al2O3/Sm2O3, Al2O3/E2O3 (E2O3 is a rare earth oxide mixture from xenotime) and Al2O3/La2O3 as liquid-phase formers. Fracture toughness, K1C, is an important mechanical property that often restricts ceramic applications. The measurement of K1C is a controversial issue, both from the standpoint of the methods employed and the mathematical equations used in determining this property. Another important property of advanced ceramics that is often neglected but which is widely known in the area of refractories is the energy of fracture, which allows one to evaluate the thermal shock resistance of ceramics used in applications in which this phenomenon is present. This project has two main and equally important objectives, namely: 1) Implement the SEVNB method to measure K1C at DEMAR/EEL/USP, which, albeit widely used abroad and offering numerous advantages compared with other methods, is very little known and used in Brazil. 2) Introduce two more rare earth oxides as liquid phase formers in SiC sintering, taking advantage of our previous experience with other rare earth oxides. In addition to training human resources. (AU)