This research presents the results of different periods of T6 heat treatment (homogenization and artificial aging) for A356 aluminum alloy used in the fabrication of motorcycles. The samples were cast using gravity die casting, and industrial furnaces for T6 were used in the experiment. Two heat treatment conditions were used, with a total time of 7 h and 12 h, and the results were compared with the alloy without heat treatment. The effects of the reduction of treatment time on mechanical behavior were evaluated in terms of hardness, Charpy and tensile tests, as well as morphological analysis of fractures and microstructural behavior via optical microscopy, SEM-EDS, measurement of eutectic Si evolution, and XRD. Excellent mechanical properties were achieved with a treatment period of 7 h, which achieved a yield strength of 226.58 (±3.76) MPa, tensile strength limit of 264.78 (±4.27) MPa and elongation of 3.41 (±0.47) %. This is competitive with other cast alloys subjected to T6 heat treatment in longer treatment cycles. The peak of hardness and highest impact resistance was recorded for the sample treated for 12 h; however, in the impact test, there was no significant difference between the two experiments.

The COVID-19 pandemic has highlighted the need to develop new materials with antiviral properties that are low cost and easy to manufacture, such as those obtained through 3D printing. This work aimed to produce and characterize PETG filaments with added copper nanoparticles (NCu), looking for virucidal properties. Filaments were prepared with 0%, 0.75% and 1% NCu and samples were then printed in 3D. The samples were subjected to nanoindentation tests, thermogravimetric analysis (TGA) and digital optical microscopy. The results indicated an increase of approximately 48% in the modulus of elasticity of the nanocomposites with 0.75% and 1% NCu compared to pure PETG. TGA analysis showed that the nanocomposite with 1% NCu had greater thermal stability, with degradation starting at 402 °C, 19 °C higher than pure PETG. In addition, this material showed a second degradation peak and a mass loss of up to 90%, compared to 15% observed in pure PETG. The data obtained shows that the addition of NCu to PETG can significantly improve its mechanical and thermal properties, making it promising for applications requiring resistance and virucidal action.

A fabricação seriada de peças moldadas por injeção é uma tarefa de usinagem exigente, especialmente em termos de precisão e qualidade das superfícies. Moldes de injeção são produzidos por processos de usinagem e EDM. O aço P20 é amplamente utilizado devido às suas ótimas propriedades mecânicas, como boa tenacidade e estabilidade dimensional, sendo ideal para moldes de injeção de plástico e matrizes de fundição sob pressão. Na produção de cavidades e insertos, ferramentas de desbaste e acabamento por fresagem possuem limitações que impedem o acabamento superficial pela usinagem convencional. Detalhes complexos e materiais duros exigem a utilização de EDM. Durante a definição dos detalhes da superfície, programadores enfrentam desafios técnicos que afetam a qualidade, custo e produtividade. A escolha entre eletrodos de cobre ou grafite é uma incógnita que pode influenciar a eficiência produtiva. Este trabalho propõe um método para definir a escolha do eletrodo, considerando custo e confiabilidade no projeto, fabricação e uso, visando o menor custo, risco e melhor acabamento superficial em aço P20. Baseado em estimativas de custo do material e tempo de usinagem, o método mostrou-se objetivo, rápido, de baixo custo e alta qualidade, conforme análises de tempo, custo e confiabilidade do processo.

The increase in global polymer production has raised concerns about the environmental impacts caused by the inappropriate disposal of these materials. One widely used alternative to mitigate this problem is to reduce the consumption of virgin raw materials through recycling processes. In this study, mixtures of virgin and recycled polypropylene, derived from waste from the manufacturing of parts for two-wheeled vehicles, in proportions of 5, 10 and 15%, were analyzed to evaluate the impact on the mechanical properties of tensile strength, hardness and impact. Compared to virgin PP, there was a reduction in mechanical properties, but only the mixture with 15% recycled material did not meet the minimum quality requirements specified. The result of the study indicate the feasibility of using percentages of 5 and 10% recycled PP in the components manufacturing process for two-wheeled vehicles, contributing to the reduction of production costs and environmental impacts.