Determinação da vida de brocas utilizadas em implantodontia e influência das condições de corte

• Ano de defesa: 2009
• Autor(a) principal: Carneiro, Marcelo Bertolete
• Orientador(a): Machado, Álisson Rocha
• Banca de defesa: Gomes, Vanderlei Luiz , Silveira, José Luis Lopes da , Luiz, Nelis Evangelista
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia
• Programa de Pós-Graduação: Programa de Pós-graduação em Engenharia Mecânica
• Departamento: Engenharias
• País: BR
• Palavras-chave em Português: Usinabilidade; Brocas odontológicas; Temperatura de usinagem; Força de avanço; Desgaste da ferramenta; Usinagem; Brocas (Ferramenta); Ferramentas para cortar metais; Implantodontia
• Palavras-chave em Inglês: Dental implantology; Machinability; Dentistry drills; Machining temperature; Thrust force; Tool wear
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS::ENGENHARIA MECANICA
• Link de acesso: https://repositorio.ufu.br/handle/123456789/14837

The aim of this work is to determine the life of twist drills used for dental implantology when drilling bovine tibia bones and to study the influence of the cutting conditions. The inputs variables considered were the cutting tool material, the feed velocity and the spindle speed. The outputs variables monitored were the number of drilled holes, the workpiece temperature, the thrust force and the tool wear. The tests were carried out in a CNC machine center and the cutting parameters were varied following a 23 experimental design. Three types of uncoated tool materials were used, a martensitic stainless steel (M340/Böhler), an austenitic stainless steel (AISI 316L) and a ceramic (zircon stabilized with Y2O3). The tool lives were expressed by the number of drilled holes considering a limit of the workpiece temperature of 47ºC, used as the end of tool life criterion. The temperatures were monitored by using three thermocouples of the type T (cupper-constantan) inserted in the work material samples, positioned very close to the drill wall. The thrust force was measured with a Kistler rotating dynamometer. A data acquisition board and a computer were used for automation of the measurement system. A mixture of 20% of car radiator fluid and water was applied as coolant (irrigation) with a flow rate of 160 ml/min. The results showed that the martensitic stainless steel outperformed the austenitic stainless steel and the ceramic material. The lowest temperatures and a conformity state at the clinic standard for thrust force values were obtained with the highest cutting parameters (45 mm/min and 2500 rpm). It was observed that the higher feed velocity promoted a temperature drop, while the higher spindle speed decreased the thrust force.