In the aluminum die casting process, erosion, corrosion, soldering, and die sticking have a significant influence on tool life and product quality. A number of coatings such as TiN, CrN, and (Cr,Al)N deposited by physical vapor deposition (PVD) have been employed to act as protective coatings due to their high hardness and chemical stability. In this study, the wear performance of two nanocomposite AlTiN and AlCrN coatings with different structures were evaluated. These coatings were deposited on aluminum die casting mold tool substrates (AISI H13 hot work steel) by PVD using pulsed cathodic arc evaporation, equipped with three lateral arc-rotating cathodes (LARC) and one central rotating cathode (CERC). The research was performed in two stages: in the first stage, the outlined coatings were characterized regarding their chemical composition, morphology, and structure using glow discharge optical emission spectroscopy (GDOES), scanning electron microscopy (SEM), and X-ray diffraction (XRD), respectively. Surface morphology and mechanical properties were evaluated by atomic force microscopy (AFM) and nanoindentation. The coating adhesion was studied using Mersedes test and scratch testing. During the second stage, industrial tests were carried out for coated die casting molds. In parallel, tribological tests were also performed in order to determine if a correlation between laboratory and industrial tests can be drawn. All of the results were compared with a benchmark monolayer AlCrN coating. The data obtained show that the best performance was achieved for the AlCrN/Si₃N₄ nanocomposite coating that displays an optimum combination of hardness, adhesion, soldering behavior, oxidation resistance, and stress state. These characteristics are essential for improving the die mold service life. Therefore, this coating emerges as a novelty to be used to protect aluminum die casting molds.

Purpose: – This article aims to collect data on the aluminum alloy 7050-T7451 machinability used in the manufacturing of aeronautical structures, using the combination of the jatropha vegetable-base soluble cutting oil in relation to the canola vegetal and semisynthetic mineral oils and the technique to apply cutting fluid by flood in relation to the Minimum Quantity Lubrication (MQL) in the milling process (HSM – high-speed machining). Design/methodology/approach: – It was observed that the jatropha vegetal cutting oil presented the best results in relation to requirements for lubrication, superficial mean roughness (index Ra) and shape errors in relation to the other oils in both the techniques to apply fluid which were tested. Comparing the application techniques, the jatropha vegetal oil offered an increase in the life span of the cutting tool, using the flood technique, exceeding in almost six times the machined length of the cutting tool in relation to the MQL technique in the same process conditions. Findings: – The Jatropha vegetable-base cutting oil, besides being produced from a renewable source, has inherent characteristics that can help attain a sustainable manufacturing, mainly with the use of the flood technique to apply cutting fluid in the aluminum alloy 7050-T7451 machining. Originality/value: – The Jatropha (vegetable) oil, in relation to its physicochemical properties, appeared to be the best one fit for being used in the machining of aluminum alloys 7050-T7451 because it did not interfere with any of the elements involved in the formation of intergranular corrosion and/or pitting, which are not allowed in the aeronautical production of parts. Jatropha (vegetable) cutting oil, besides being produced from a clean and renewable source, has the inherent characteristics that can help attain a sustainable manufacturing.

The global transition towards environmentally friendly energy sources plays a major role in addressing both energy security and climate change. Brazil is at the forefront of this transition due to its rich natural resources and increasing investments in biofuels. Therefore, this investigation examines the consumption patterns and interactions between ethanol, primarily sourced from sugarcane, and gasoline within Brazil’s energy framework. Ethanol’s renewability, reduced environmental impact, and superior combustion characteristics position it as a feasible substitute for traditional fossil fuels. Nonetheless, obstacles like competition for land use and inadequate distribution infrastructure impede its widespread acceptance. This study explores the economic interaction between ethanol and gasoline, focusing on pricing dynamics and regional influences. Using consumer preferences and the accessibility of ethanol, this research identifies a range of price ratios within which consumer preferences shift from gasoline to ethanol in various Brazilian regions. The study also classifies Brazilian states into three distinct ranges based on the ethanol-to-gasoline price ratio in 2023 for a granular analysis of the economic dynamics influencing fuel choice. The research identifies states with competitive and dominant ethanol markets by examining the interplay between ethanol market share, fuel prices, and the adoption of flex-fuel vehicles (FFVs) in the country. Lastly, the findings support the importance of regional economic conditions and the influence of price ratios on consumer behavior, highlighting that ethanol’s market share does not always correlate with favorable pricing.

To achieve Sustainable Development Goal 7 (SDG7) and improve energy management efficiency, it is essential to develop models and methods to forecast and enhance the process accurately. These tools are crucial in shaping the national policymakers’ strategies and planning decisions. This study utilizes data envelopment analysis (DEA) and bootstrap computational methods to evaluate Brazil’s energy efficiency from 2004 to 2023. Additionally, it compares seasonal autoregressive integrated moving average (SARIMA) models and autoregressive integrated moving average (ARIMA) forecasting models to predict the variables’ trends for 2030. One significant contribution of this study is the development of a methodology to assess Brazil’s energy efficiency, considering environmental and economic factors to formulate results. These results can help create policies to make SDG7 a reality and advance Brazil’s energy strategies. According to the study results, the annual energy consumption rate is projected to increase by an average of 2.1% by 2030, which is accompanied by a trend of GDP growth. By utilizing existing technologies in the country, it is possible to reduce electricity consumption costs by an average of 30.58% while still maintaining the same GDP value. This demonstrates that sustainable development and adopting alternatives to minimize the increase in energy consumption can substantially impact Brazil’s energy sector, improving process efficiency and the profitability of the Brazilian industry.

A demanda por produtos sustentáveis, principalmente devido à pressão dasociedade e à escassez de recursos naturais ou de regulamentações, vem setornando um mercado atrativo aos consumidores. O governo brasileiro estádiscutindo a regulamentação sobre compras governamentais sustentáveiscom a indústria para conhecer as particularidades de cada setor e estabelecerestratégias de atuação. Esta pesquisa propõe um método para identificarrequisitos de sustentabilidade utilizando a ferramenta de mapas cognitivos,na visão do setor industrial têxtil e de confecção, para servir de subsídio nasdiscussões e negociações governamentais e que possam ser utilizados comoreferência para esse setor. Como resultado, foram listados para as dimensõesambiental, social, econômica e tecnológica, respectivamente, 16, 19, 11e 8 requisitos. Com isso, essa pesquisa pode auxiliar o setor em estudo adefinir os critérios de sustentabilidade para seus produtos e ainda identificaroutros requisitos que devem ser incluídos e priorizados nas discussões sobrecompras públicas sustentáveis.