Estudo de caso: formulação de custo de um produto de usinagem em uma pequena empresa

Many variables are indirectly involved in the transformation of raw material into a metallurgical industry, such as machine hours, hours of hand labor directly and / or indirect, setup time, etc. This research focuses on the complexity of formulating the cost of metallurgical products, based on a case study, in which one has incurred a large loss on the sale of a product called Punch. The main objective of this work is to define the variables of the cost of members and other metallurgical products, so simplified general, checking what were the failures costing the case studied, in order to help others. The method of formulating cost was determined as recommended by SEBRAE guidance for small businesses. The results showed a loss R$ 13.201,00 in the batch of 15 units of punch. Possible improvements have been identified for reducing the production cost

Determinação de metais pesados no caranguejo comestível Ucides cordatus (Crustacea: Decapoda)

Não disponível

Uso das técnicas de difusão em filmes finos por gradiente de concentração (DGT) para avaliação de metais disponibilizados em passivos de mineração de Urânio

The objective of this work is to use the technique of diffusion by concentration gradient films (DGT) for evaluation of dissolved urano in hydro bodies. For this we chose this work as a systems investigation of water bodies in the region of Poços de Caldas, state of Minas Gerais, because, there is a large amount of mining of uranila. The technique to be used to evaluate the potential for dissolved metals analysis involves the use of passive samplers with application in in situ. This allows detection with excellent sensitivity and selectivity allowing the determination of the labile fraction of dissolved metals

Caracterização do defeito tipo trinca de laminação, ocorrido no processo de laminação de barras de aço

The mechanical forming processes are the main means of transformation. Among all processes, the most used is rolling and broken down into flat and non-flat products. In the flat products are classified plates, and products no plans bars and profiles. Thus laminating products, mostly, are the raw materials for other processes of transformation, as stamping, forging, machining, bending and more. This work has focused on non-flat products, classified as bars and rods, watching a key point in the proceedings that is the product quality. Here is demonstrated through metallographic analysis of steel bars, hot-rolled, the characteristics of surface cracks in these bars

Diagnóstico ambiental do Córrego Bandeirantes, município de Rio Claro, SP: parâmetros biológicos e metais-traço

This study was conducted to verify water quality and environmental impacts related to the occupation of the watershed of the Bandeirantes stream, located in Rio Claro, SP. The intention is to propose measures to enable the mitigation of negative impacts, and boosting the recovery and maintenance of the quality of water resources, preventing its complete degradation. Water analysis were performed at three different points, east, crossing the Ring Road (dirt road) and near the confluence with the Ribeirão Claro. The results indicated significant degradation of water, especially after the crossing, where it witnessed the accumulation of solid waste and easy access to the stream, both for animals as for people, due to limited riparian it. Another impact was observed the current construction of the Forum of Rio Claro in the right side of the stream studied, causing change in the landscape, change the flow properties and removal of existing vegetation at the site of work, defined as an environmentally protected area, as determined by existing law. Measures such as: restoration of riparian zones, effluent treatment, planned urban growth and environmental education of the population, would be essential to mitigate the environmental impacts of watershed Bandeirantes stream

Melhoria da qualidade de um processo de usinagem utilizando as técnicas de avaliação de Taguchi

Delivering to the customers a product or service with the expected quality associated to the huge competitiveness that exists in the market nowadays, has been making organizations increasingly focus on quality planning using techniques which are directed towards the continuous improvement process and production optimization. Thus, this paper aims to improve a machining process using the techniques of experimental design to the optimization and this also includes the analysis of the measurement system. For this purpose, the alloy Nimonic 80A, a nickel base superalloy, was used in the process due to its widespread use for high temperatures, applying this study the robust method proposed by Genichi Taguchi, determining the influence of the factors considered input variables, cutting speed, feed rate, depth of cut, type of tool, lubrication, and material hardness, in the output or response variable, surface roughness, concluding with the use of Taguchi orthogonal array L16 and by analysis of ANOVA that the factor feed rate is significant and offers greater effect on the response variable studied, should be set to 0,12mm/rev. Moreover, the factor type of tool has more influence on the process when compared to other factors, being CP250 the one more suitable to the process. Lastly, the interaction feed rate x cutting speed provides greater significance in the process regarding to surface roughness variable, being the best match between them 0,12mm/rev to the feed rate and 90m/min to the cutting speed. In order to evaluate the measurement system, it was applied the repeatability and reproducibility method (R&R), through which we saw that the system needs improvement (R & R = 88.04% >>> 30%) as the value found in the study was well above compared to the one that classifies the system as inappropriate

Usinagem da liga de níquel inconel 718 com pastilhas de cerâmica

The machining of super alloys resistant to high temperatures such as nickel alloys, inconel 718 specifically, is a very difficult job to obtain improvements in the process, due to the difficulty of machining at high cutting speeds, the use of these alloys in industries showed great developments in recent years, its application in aeronautical industry spread being used in vane turbo, compressor parts, props and set elements. The automotive, chemical, medical and others also took advantage of the great features of inconel 718 and has used the material. The high temperature resistant alloys have high machining difficulty, a fact that is associated with high cutting forces generated during machining which result in high temperatures. High levels of temperatures can cause deterioration of the cutting edge, with subsequent deformation or breakage, wear most common obtained in machining such materials are flank wear the formation of built-up edge for cutting and notch wear. The experimental part of the work consists in machining of nickel-based alloy Inconel 718 heat treated for hardness, using a tool based ceramic silicon nitride Sandvik (Si3N4) in order to compare the best results obtained in the master's thesis of SANTOS (2010) who used a tool ceramics also the basis of silicon nitride which was developed in the doctoral thesis of SOUZA (2005). Assays were performed on a CNC lathe and was noted for each cutting edge results obtained. Tests were made starting from an initial condition of the tool with cutting speed of 200 m/min, feed 0.5 mm and 0.5 mm depth of cut was reduced cutting speed for the subsequent tests with the same conditions of feed and depth of cut. The tool presented wear instant under two 200 m/min and 100 m/min, premature rupture of 50 m/min and finally cut provided with difficulty... (Complete abstract click electronic access below)

Auxílio na tomada de decisão na compra de uma máquina de usinagem a laser

Decision making is one of the most important factors for growth and future, both from a business, as in people's life and attitudes in the simplest of everyday day. This work aims to assist decision making in buying a laser cut machine, a manufacturer of auto parts and wheels, and later this technique can be considered to acquisition of other equipment. In this case was used the AHP to aid the decision by multiple criteria. First we analyzed the most important criteria of the current machine for the application of the method and were later made the application and sensitivity analysis

Otimização do processo de usinagem da superliga nimonic 80A utilizando o Método de Taguchi

Atualmente, atender as necessidades dos consumidores é uma das metas mais importantes, os consumidores estão em busca de produtos com qualidade e preços mais acessíveis, para isso, é indispensável que as empresas se atualizem para melhorar seus produtos e serviços. Com este cenário, as superligas estão cada vez mais ganhando mercado, pois possuem ótimas propriedades, principalmente em relação a operar em temperaturas elevadas, podendo proporcionar maior eficiência para motores que necessitam trabalhar em altas temperaturas. Em contra partida a essa vantagem, as superligas possuem uma baixa usinabilidade, sendo importante a análise do processo de usinagem para se tornarem mais aplicáveis. Este trabalho visa à otimização do processo de torneamento cilíndrico da superliga Nimonic 80A, com o intuito de melhorar a qualidade do produto, utilizando o Método de Taguchi, com o arranjo ortogonal L16, sendo o comprimento de corte definido como variável resposta e analisados seis fatores que poderiam influenciar na sua variação, tais fatores são: velocidade de corte, avanço, profundidade de corte, tipo de pastilha, lubrificação e dureza do material. Os resultados obtidos demonstraram que os fatores avanço, tipo de pastilha e lubrificação são significativos e exercem influencia no processo, sendo que o avanço deve ser ajustado no nível de 0,12 mm/rev, a pastilha a ser utilizada deve ser CP250 e a lubrificação deve ser feita de maneira abundante, para a otimização do processo. Com a análise dos resultados, também podemos observar a eficiência e confiabilidade do método utilizado, mostrando resultados coerentes

Redução do tempo de setup de máquinas de usinagem em uma industria automobilística

Continuous improvement of industrial processes is one way to become companies more competitive in the market. For this, a fairly widespread use is the methodology of lean production systems, by eliminating waste. One of the tools of these systems is the method of rapid exchange of die or also called SMED, which will be applied in this study. The study aims to develop proposals for reducing the time of set up of two machines in two machining lines, watching also the ergonomics and safety conditions in this operations. The set up time reduction is justified among others, due to increase the machine productivity. In applying the connecting rod machining line, there were two types of exchange. Reductions in time to set up proposals reached values of 47% to one of them, and 55% to the other. It is important to underline that to reach this result, there was no need for large investments. In the application in block machining line, was developed an improvement in the ergonomic area. It was placed a pulley block that came to increase the time of tool change. Aiming to improve the security of the exchange, without productivity loss, the method was applied to reduce this time. It was developed two proposals.: the first would reduce that time by 19%, and does not require many resources of the company. The second involves the parallelization of the exchange, so that the reduction is 48%. However, this proposal requires one more manpower at the time of exchange and it is not always possible

Metais pesados, atributos químicos e bioquímicos em latossolos e plantas de milho após aplicação de lodo de esgoto por dezesseis anos consecutivos

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Influência das substâncias húmicas aquáticas na genotoxicidade dos metais em tilápias do Nilo (Oreochromis niloticus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos dos parâmetros de usinagem no acabamento superficial de materiais cerâmicos a verde

Pós-graduação em Engenharia Mecânica - FEB

Metais pesados: fonte e ação toxicológica

A contaminação do solo pelo descarte de substâncias tóxicas adquiriu, nos últimos anos, maior atenção da comunidade científica a qual tem alertado a população dos países, em geral, para as conseqüências, em especial, as patologias que podem ocorrer quando estas substâncias adentram nossa cadeia alimentar. Neste trabalho procurou-se apresentar as fontes de contaminação e a toxicidade do cádmio, do chumbo, do mercúrio e do manganês, quando estes se encontram em níveis elevados no solo e nos mananciais superficiais e subterrâneos. Com relação aos três primeiros metais, sua alta dosagem pode provocar, no ser humano, diversos tipos de câncer, lesões no estômago e pulmões, além de alterações importantes nos sistemas imunológico e nervoso central. O manganês, um dos metais mais comuns da crosta terrestre, largamente utilizado pela indústria e disponibilizado, em grandes quantidades no meio ambiente, em doses elevadas pode causar doenças pulmonares e neurológicas.

Teores elevados de metais potencialmente tóxicos em amostras de fertilizantes

A contaminação do solo por metais potencialmente tóxicos constitui um dos principais problemas ambientais. Por meio da lixiviação e percolação das águas, esses metais podem ser mobilizados e vir a contaminar mananciais superficiais e subterrâneos, comprometendo sua qualidade. A biodisponibilização desses metais para as plantas e, a partir dessas, para o homem é outro desfecho negativo dessa situação. O cádmio é um elemento tóxico. Os teores encontrados nos solos costumam não oferecer riscos. Porém, esses teores são potencializados pela utilização de fertilizantes. O níquel pode ser carcinogênico em doses elevadas. Sua presença em fertilizantes fosfatados proporciona maiores concentrações do metal no solo. É amplo o registro sobre efeitos do excesso desses metais, tanto em plantas, quanto em animais e no ser humano. O manganês é um dos elementos mais abundantes na crosta terrestre e se encontra largamente distribuído em solos, sedimentos, rochas, água e materiais biológicos. Contrariamente aos dois metais anteriores, esse micronutriente é um elemento essencial ao ser humano. Sua carência causa inúmeras enfermidades, por outro lado, seu excesso também. Nesse caso, poucos são os relatos sobre o assunto. Nesse estudo foram utilizados métodos de extração de metais de fertilizantes e se constatou que, quando presentes, os metais cádmio e níquel apresentaram concentrações proibitivas o que é motivo de preocupação e demonstra a falta de controle sobre a indústria de insumos agrícolas. Para o manganês não há parâmetros orientadores com limites de teores, mas com certeza, são necessários trabalhos nesse sentido para se evitar seu consumo indiscriminado.