Quality evaluation of Co-Cr castings as a function of three fast cycle coatings

• Grant number: 06/07229-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2007
• End date: January 31, 2008
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Renata Cristina Silveira Rodrigues Ferracioli
• Grantee: Fabrício Figueiredo de Carvalho
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The type of investment and the technique used for investment influence the final quality of the castings. Nowadays, there are several investment materials, in the market, presenting purpose of quick heating. This technique provides castings which properties need to be evaluated for routine use in commercial laboratories. The aim of this study will be evaluate the effect of the quick heating investments on the quality of Co-Cr castings. Roughness, microhardness and strength flexure resistance will be evaluated. For the tests, plates in rectangular form (28 mm length, 3mm width and 1mm thickness) will be obtained, casted in Co-Cr alloy. The metal will be casted by voltaic-arc and injection of metal in the mold by vacuum-pressure. Roughness test will be made in a surface roughness tester Mitutoyo SJ-201P at 0.05mm/s speed and cut-off of 0.8mm. For the microhardness Vickers test, the samples will be cut and three areas from the superficial layer will be performed: 10mm, 50mm and 150mm. Strength flexure will be performed using a universal testing machine EMIC MEM 2000 at 0.5mm/min speed with 500 Kg load cell. The number of samples will be determined in a pilot study. The results will be analyzed by an appropriate statistical test. (AU)