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Abstract(s)
O processamento, conformação e tratamentos superficiais do cobre e as suas ligas metálicas são de extrema importância na engenharia industrial derivado às suas caraterísticas físicas e químicas, tais como, alta condutividade elétrica, elevada resistência à corrosão, facilidade na sua fabricação, boa resistência à tração e ainda boas propriedades de recozimento e solda sem existirem custos muito elevados quando comparado com metais de características idênticas, neste caso concreto, é analisada a indústria de transformação de produtos de luxo.
Esta dissertação resulta de um estágio curricular desenvolvido na empresa F.P.L – Fábrica de Produtos de Luxo, que consistiu na análise das superfícies das peças metálicas durante as diferentes etapas do processo de polimento desenvolvido na empresa, através do microscópio eletrónico de varrimento e consequentemente avaliar a qualidade da microestrutura das mesmas.
Para este estudo analítico foram utilizadas 4 referências diferentes de produtos, designados por produto A, B, C e D, na qual a composição geral se baseia num latão do tipo 60:40, sendo a liga metálica constituída por 60% de Cu (cobre) e 40% de Zn (zinco), concentração essa, que é fornecida pelo fabricante das peças.
As análises foram realizadas em diferentes etapas do processo de transformação, desde que as peças chegam à fábrica em bruto até que estejam prontas a ser enviadas para o cliente. Os três processos analisados foram: peça em bruto (quando chega à empresa sem qualquer tipo de tratamento prévio), peça lapidada (fase em que se utilizam lixas de diferentes rugosidades de forma a retirar o “bruto” da peça, para tornar o polimento final mais rápido e eficaz) e por fim, a peça polida e lavada (fase em que a peça está pronta a ser analisada no controlo da qualidade da empresa e caso cumpra os requisitos é expedida para o cliente).
Das análises efetuadas às etapas de polimento de diferentes peças observou-se que o polimento contribui para a melhoria da qualidade superficial reduzindo significativamente a rugosidade das peças (após o polimento, a rugosidade deverá ser inferior a 0,10µm), eliminar manchas, riscos e pontos duros. Mesmo com ações mecânicas de polimento mais severas, devido à geometria mais complexa de algumas peças, não surgiram defeitos localizados nessas zonas.
The processing, conformation and superficial treatments of copper and its metallic alloys reveal an extreme significance in the field of industrial engineering, due to its physical and chemical attributes, such as high electric conductivity and corrosion resistance, easiness in its fabrication, decent tensile strength levels, and even favorable characteristics to the annealing and welding. Due to the absence of high machination costs, when compared to metals with similar features, as it is presented in this particular study, an analysis is made comprising the current processes in the luxury products transformation industry. This dissertation results from a developed curricular training in the company “F.P.L – Fábrica de Produtos de Luxo”, which consisted in the surface analysis of metallic parts during the different stages of the burnishing process developed in the firm, though the use of an electronic scanning microscope, for subsequent microstructure quality evaluation. In order to complete this analytical study, 4 different references of products were used, designated by product A, B, C and D, in which the general composition is based on 60:40 type brass, whose metallic alloy is composed by 60% of Cu (Copper) and 40% of Zn (Zinc), being these values of concentration supplied by the parts manufacturer. The analyses were taken into account at different stages of the transformation process, since their arrival at the plant, in raw state, until they are ready to be sent for the costumer. The three analyzed processes were: raw part (when it arrives at the company without any type of prior treatment), engraved part (phase when there are used sandpapers of different roughness in order to minimize the part’s abnormalities and harshness level) and finally, the polished and washed part (phase where the latter is ready to be analyzed in the company’s quality control department and, in the case that it fulfills the requirements, is forwarded to the costumer). From the accomplished analyses made respecting the burnishing stages of the different parts, it was observed that this process contributed to the general improvement of the superficial quality, significantly reducing the part’s roughness (after burnishing, this parameter will have to be inferior than 0,10µm), eliminating stains, scratches and hard points. Even with the use of harsher mechanical burnishing activities, motivated by the higher complexity of some parts, the appearance of local faults was not verified.
The processing, conformation and superficial treatments of copper and its metallic alloys reveal an extreme significance in the field of industrial engineering, due to its physical and chemical attributes, such as high electric conductivity and corrosion resistance, easiness in its fabrication, decent tensile strength levels, and even favorable characteristics to the annealing and welding. Due to the absence of high machination costs, when compared to metals with similar features, as it is presented in this particular study, an analysis is made comprising the current processes in the luxury products transformation industry. This dissertation results from a developed curricular training in the company “F.P.L – Fábrica de Produtos de Luxo”, which consisted in the surface analysis of metallic parts during the different stages of the burnishing process developed in the firm, though the use of an electronic scanning microscope, for subsequent microstructure quality evaluation. In order to complete this analytical study, 4 different references of products were used, designated by product A, B, C and D, in which the general composition is based on 60:40 type brass, whose metallic alloy is composed by 60% of Cu (Copper) and 40% of Zn (Zinc), being these values of concentration supplied by the parts manufacturer. The analyses were taken into account at different stages of the transformation process, since their arrival at the plant, in raw state, until they are ready to be sent for the costumer. The three analyzed processes were: raw part (when it arrives at the company without any type of prior treatment), engraved part (phase when there are used sandpapers of different roughness in order to minimize the part’s abnormalities and harshness level) and finally, the polished and washed part (phase where the latter is ready to be analyzed in the company’s quality control department and, in the case that it fulfills the requirements, is forwarded to the costumer). From the accomplished analyses made respecting the burnishing stages of the different parts, it was observed that this process contributed to the general improvement of the superficial quality, significantly reducing the part’s roughness (after burnishing, this parameter will have to be inferior than 0,10µm), eliminating stains, scratches and hard points. Even with the use of harsher mechanical burnishing activities, motivated by the higher complexity of some parts, the appearance of local faults was not verified.
Description
Keywords
Controlo de Qualidade. Diagramas de Fases Lapidação Latão Microestrutura Polimento Rugosidade