O entendimento de usinabilidade passa pelo estudo de fenômenos de formação de cavaco, qualidade superficial, mecanismos de desgaste de ferramenta e a influência de parâmetros de corte no material usinado. Com a crescente demanda da indústria moderna para materiais com melhores propriedades e melhor usinabilidade, as ligas Al-Sn tornam-se interessantes devido às suas características para aplicações tribológicas. Neste trabalho, foi realizada a análise da usinabilidade da liga Al-10%Sn solidificada direcionalmente em um dispositivo horizontal refrigerado à água sob condições transientes de extração de calor, correlacionando a rugosidade média (Ra) com a macroestrutura e microestrutura de solidificação (espaçamento dendrítico primário). No processo de torneamento, os corpos-de-prova da liga foram submetidos ao sangramento à seco em diferentes posições. Os resultados experimentais são representados por meio funções do tipo potência, que indicam o decréscimo da rugosidade com a diminuição do espaçamento dendrítico primário.

The increasing technological advances obtained both in the development of new materials and of machine tools increased the demand for the machining processes and in addition, the use of increased cutting fluids. However, it’s necessary to have characteristics that don’t harm the environment and the operator. In machining processes, cutting fluids, when properly chosen and applied, may reflect benefits during the manufacturing process. This work evaluated the performance of a commercial cutting fluid by comparing it with vegetable oil extracted from carapa guianensis in the abnt 1045 steel turning process. The cutting speed (vc), tool feed (f) and depth (ap) and the influence of the use of both of them on the metal was verified with the following variables: chip analysis, surface finish, cutting temperature and tool wear. It was observed that with the use of andiroba oil, better chip was generated for the safety of the operator, higher cutting temperatures in the piece, higher tool wear and better surface finish with a difference of 23% compared to commercial cutting fluid. Thus, the fluid from andiroba based on the conventional application demonstrated a viable alternative in the turning process of abnt 1045 steel, because it’s biodegradable and reduces petroleum-based cutting fluids.

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Você tinha o hábito de revisar o conteúdo de Cálculo 1 no mesmo dia da aula? 62 219 9 Você participou ou participa de algum projeto de pesquisa ou extensão 179 102 10 Você usa transporte público para vir à UFPA? 226 55 11 Você mora com a família? 235 46 12 Você mora em Belém? 232 49 13 Você possui renda própria? 49 232 Fonte: Elaborado pelos autores As informações obtidas por meio do questionário foram cadastradas no software IBM SPSS. De posse dos dados registrados iniciou-se a segunda etapa do procedimento, a criação de um modelo matemático obtido via regressão logística. Como o questionário utilizado só possui perguntas cujas

In machining, the proper selection of cutting fluids result in benefits that vary from superior quality of the machined component to manufacturing cost. In addition, the must have characteristics that do not harm the user and the environment. In this sense, this work evaluates the effects of the vegetable base oil extracted from Carapa Guianensis in the external cylindrical turning process of the ABNT 1020 and 1045 steel grades. Highspeed steel tools were tested under roughing and finishing conditions. In addition to the physico-chemical characterization (dynamic viscosity at 40 °C and pH) of fluid, the chip form, surface finish, tool wear and workpiece temperature were evaluated. After characterization of oil, there were recorded in the dynamic viscosity at 40 °C of 0.11 Pa.s and pH of 2.3. The average roughness recorded were very close to those usually reported in the literature for finishing turning for ABNT 1020 and 1045 steels. It was also observed that the workpiece temperatures were higher when machining the ABNT 1020 steel grade under finishing condition than for other steel and conditions tested. Based on these findings, the andiroba oil delivered the conventional coolant technique demonstrated to be a technically viable alternative to conventional coolants in the turning process of ABNT 1020 and 1045 steels, because of it biodegradability characteristics and to reduce petroleumbased cutting fluids in the machining processes.