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Matriz de decisão para seleção de materiais aplicados em tanques de armazenamento de hidrogênio verde

2026-04-27T18:49:23Z

Título: Matriz de decisão para seleção de materiais aplicados em tanques de armazenamento de hidrogênio verde Autor(es): Martins, Julyana Xavier Abstract: Green hydrogen has emerged as a promising energy carrier in the context of the transition toward low-carbon energy systems. However, one of the main challenges associated with its large-scale application is related to safe and efficient storage, particularly regarding the appropriate selection of materials used in the manufacturing of storage tanks, which must withstand high pressures, typically in the range of 200 to 700 bar. In this context, this study aims to develop a multicriteria decision matrix to support the selection of materials for Type I metallic tanks used in green hydrogen storage. The methodology is based on the Simple Additive Weighting (SAW) method, which belongs to the family of compensatory multicriteria decision-making methods. Technical, economic, and environmental criteria were defined, namely: mechanical strength, density, resistance to hydrogen embrittlement, corrosion resistance, relative cost, and sustainability. The analyzed alternatives included austenitic stainless steel AISI 316L, aluminum alloy AA 6061, titanium alloy Ti-6Al-4V, and low-alloy Cr–Mo steel (34CrMo4). Qualitative criteria were converted into numerical values using an ordinal scale, allowing their integration into the decision model. Subsequently, the data were normalized and weights were assigned based on technical judgment, considering the context of stationary storage. The results indicated austenitic stainless steel AISI 316L as the most suitable alternative among those evaluated, presenting the best balance between the selected criteria. It is concluded that the proposed multicriteria model does not replace an in-depth literature review but serves as a decision-support tool that strengthens the selection process by providing a structured, transparent, and consistent evaluation of materials for green hydrogen storage tanks. Tipo: TCC

Análise da solidificação e transformações no estado sólido através de simulações termodinâmicas e termogravimetria em ligas de níquel produzidas in situ por manufatura aditiva.

2026-04-23T11:48:20Z

Título: Análise da solidificação e transformações no estado sólido através de simulações termodinâmicas e termogravimetria em ligas de níquel produzidas in situ por manufatura aditiva. Autor(es): Alcântara Filho, Luis Eduardo Vieira Abstract: Alloy design is currently a strategic tool in materials engineering, enabling the development of alloys with optimized properties for welding and additive manufacturing applications. In this context, nickel-based alloys stand out due to their exceptional combination of mechanical properties, thermal stability, and corrosion resistance. As an alternative for processing these materials, duble-wire GMAW (Tandem) technique has been proposed. This process allows for the simultaneous melting of different filler metals, facilitating in-situ alloy synthesis. Furthermore, the flexibility of the process enables precise adjustment of the resulting chemical composition by controlling the melting rates. In this work, AWS ERNiCrMo-3 (INCONEL 625) and AWS ERNiCrMo-4 (HASTELLOY C276) filler metals were co-melted to produce in situ alloys, with the resulting compositions based on the share of each commercial alloy: alloy A (50% 625 / 50% C276), alloy B (35% 625 / 65% C276), and alloy C (65% 625 / 35% C276). To analyze the solidification behavior, Scheil-Gulliver simulations were performed using Thermo-Calc® and JMatPro® software.Additionally, four conditions were simulated to evaluate the stability of the formed phases: (a) with σ-phase and with carbon inclusion; (b) without σ-phase and with carbon inclusion; (c) with σ-phase and without carbon inclusion; and (d) without σ-phase and without carbon inclusion. The simulations of the in-situ alloys indicated the formation of phases such as σ, μ, δ, P, M6C, MC, and Laves, in addition to the FCC-Ni (γ-Ni) matrix.Complementing the solidification analysis, solid-state transformations occurring during both cooling and aging heat treatments were investigated. For this purpose, TTT and CCT diagrams were simulated using JMatPro® for in-situ alloys A, B, and C, which indicated the formation of phases such as P, μ, σ, γ’’, and δ, as well as M₆C and M23C6 carbides.To validate the thermodynamic simulations, DSC scans were conducted, in which two peaks were identified during solidification, and no thermal events were observed during cooling below the Tsolidus. Tipo: TCC

Avaliação de metodologias de diagnóstico de maturidade em inovação: uma análise comparativa e aplicação no contexto brasileiro

2026-04-23T11:35:51Z

Título: Avaliação de metodologias de diagnóstico de maturidade em inovação: uma análise comparativa e aplicação no contexto brasileiro Autor(es): Freire, Alice Barros Abstract: Innovation has established itself as a fundamental strategic element for the competitiveness and sustainability of contemporary organizations. However, many companies still face difficulties in understanding their level of maturity in innovation and structuring actions aligned with their organizational reality, especially in the Brazilian context. Given this scenario, this study aims to evaluate methodologies for diagnosing innovation maturity and analyze the applicability of the methodology developed by the Center for Innovation and Applied New Business (NINNA Hub) in the national context. The research adopts a qualitative, exploratory, and descriptive approach, based on a review of the literature and documents. Academic, normative, and consulting models widely used in Brazil and abroad, such as ISO 56002, Radar da Inovação, IMMM, and other consolidated references, were analyzed based on criteria such as methodological approach, dimensions evaluated, analytical depth, practical applicability, and adherence to the Brazilian context. Next, a comparative analysis of these methodologies was carried out with the model proposed by NINNA Hub. The results indicate that, although existing models offer relevant contributions to the measurement of innovation maturity, many have limitations related to methodological rigidity, low integration between qualitative and quantitative analyses, and poor adaptation to the specificities of Brazilian organizations. The NINNA Hub methodology stands out for its hybrid approach, explicit incorporation of data and artificial intelligence dimensions, connection with innovation horizons, and generation of prescriptive deliverables, such as a maturity radar and structured action plan. Tipo: TCC

Influência de Ti e Nb no comportamento microestrutural e propriedades mecânicas de aços maraging submetidos a tratamentos de ciclagem térmica

2026-04-23T11:16:26Z

Título: Influência de Ti e Nb no comportamento microestrutural e propriedades mecânicas de aços maraging submetidos a tratamentos de ciclagem térmica Autor(es): Silveira, Fábio Jorge Lemos Abstract: This study investigated the influence of thermal cycling above the austenitization temperature and the addition of niobium (Nb) and titanium (Ti) on grain refinement and mechanical performance of maraging steel M300. Three alloy variants (Ti, Ti+Nb and Nb) were subjected to repeated thermal cycles at 900 °C (5 and 10 cycles). Microstructural characterization was carried out using EBSD, XRD, and EDS, while mechanical behavior was evaluated through tensile testing, hardness test and fractographic analysis. EBSD results showed that five thermal cycles promoted effective refinement of prior austenite grains (< 20 μm) and an increase in high-angle grain boundaries, although Nb-containing alloys exhibited reduced refinement due to grain boundary pinning. XRD confirmed strain accumulation and crystallite refinement after five cycles, followed by partial recovery after ten cycles. EDS analyses revealed a transition from Ti-based precipitates to Nb–Mo intermetallics during cycling, with indications of incomplete dissolution in alloys containing only Nb. From a mechanical standpoint, Ti-containing alloys exhibited a significant increase in ductility (≈ 9% elongation), whereas Nb additions favored higher strength. The Ti+Nb variant stood out by providing a superior balance between hardness, strength, and toughness. Overall, these results demonstrate that controlled thermal cycling combined with Nb and Ti additions is an effective strategy to tailor microstructure and mechanical behavior for demanding engineering environments, offering promising alternatives for aerospace, offshore, and high-performance tooling applications, where refined grains and balanced mechanical properties are essential. Tipo: TCC