Microabrasão de compósitos de matriz metálica a base de tungstênio empregados em coroas de perfuração utilizadas em sondagem mineral

• Ano de defesa: 2008
• Autor(a) principal: Lozzer, André Menegaz
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Engenharia Mecânica; Centro Tecnológico; UFES; Programa de Pós-Graduação em Engenharia Mecânica
• Palavras-chave em Português: Prospecção mineral; Máquinas de perfuração; Engenharia Mecânica; 621
• Link de acesso: http://repositorio.ufes.br/handle/10/4139

It is important in rock core drilling for the diamond bit crown to be meticulously worn such that the cut is performed on the lithology. The objective of this work is to evaluate wear on composite matrix alloys used in perforation drill bits, produced from a tungsten powder skeleton held by an infiltrating metal alloy. Wear is evaluated through free ball micro-abrasion testing (Calowear), using abrasive slurry of Fe2O3, SiC, and SiO2. This work presents the relation between material hardness, tungsten mean size and composition of the metal powder, besides confronting acting micromechanisms in order to construct a specific wear map. Were also performed Vickers hardness, laser interferometry, and scanning electronic microscopic analysis of the wear mechanisms. It was found that composites hardness is not a determinant factor for wear resistance, as well as became evident the systemic character of the wear processes. Were found mechanisms of sliding, multiple indentation, besides the simultaneous, though dissociate, occurrence of both.