Search

Additively manufactured complex geometries from copper alloys with high thermal and mechanical properties have drawn the attention of researchers. The present contribution explores the additive manufacturing (AM) of copper-based alloys from powder particles intended for heat sink and heat exchange applications. Selective laser melting (SLM) parameters featuring low laser beam power (160 W), moderate scanning speed (320 mm/s), and high energy density (200 J/mm³) were employed to fabricate dense components from CuSn10 particles. The present work deal with structural analysis and precision investigation of microfabrication, particularly in Struts, Tubes, and Fins. Mechanical properties (compression and hardness) for Strut structure, differential pressure evaluations for Tube structure, and analyses of thermal and electrical conductivities for Fin structure were investigated. The results showed an improvement in strength compared to those of pure copper, facilitating ease of AM. The obtained results affirm the feasibility of AM, demonstrating the successful creation of complex and combined solid-porous structures using SLM process from Cu alloys. A comprehensive structural investigation and characterization of the Cu–Sn alloy is presented here, aiming to establish a standardized approach for analysing Cu alloys. The results indicate that small-scaled structures fabricated via CuSn10 alloy exhibits a thermal conductivity of 34.3 W·m⁻¹·K⁻¹, an electrical conductivity of 4.72×10⁶ S/m, a hardness of 119 HV-50, a uniform surface roughness of 6 µm, and can withstand a force loading of 1 kN.

This work presents a state-of-the-art review of micro-combustion flame dynamics and micro propulsion systems. In the initial section, we focus in on the different challenges of micro-combustion, investigating the typical length and time scales involved in micro-combustion and some critical phenomena such as flammability limits and the quenching diameter.We present an extensive collection of studies on the principal types of micro-flame dynamics, including flashback, blow-off, steady versus non-steady flames, mild combustion, stable flames, flames with repetitive extinction, and ignition and pulsatory flame burst. In the final part of this review, we focus on micropropulsion systems, their performance metrics, conventional manufacturing methods, and the advancements in Micro-Electro-Mechanical Systems manufacturing.

The Brazilian sugarcane industry generates a significant amount of waste each year, which should be properly analyzed and studied to allow an adequate recovery and application supported by the best understanding of its properties. The present work reports the ignition and burnout temperatures of sugarcane bagasse (SCB) obtained after performing a thermal analysis using four different heating rates. The intersection method (IM) and deviation method (DM) were employed to approach the ignition and burnout temperatures of the sugarcane bagasse. The ignition temperatures of the SCB measured from IM are between 250 and 263 °C, and their burnout temperatures are between 357 and 377 °C. The ignition temperature was in the range of 205 °C to 236 °C for the DM. IM is recommended for determining the ignition and burnout temperatures. In TGA, the heating rates in the range of 10 °C·min−1 and 15 °C·min−1 are suggested due to their accuracy and the contribution to timesaving in the analysis.

Industry 5.0 combines automation/digitalization with human capabilities to create a more intuitive, interactive, and sustainable working environment. Additive manufacturing, widely known as 3D printing, is a key technology used to increase customization and efficiency and reduce waste in manufacturing. Industry 5.0 enables manufacturers to create environmentally sustainable and consumer-centric products. However, there is a lack of studies on the introduction of AM technologies to Industry 5.0. The present study investigates the use of additive manufacturing for the fabrication of metallic parts/assemblies and the correlation between human-centric technologies, additive manufacturing, and environmental sustainability. Effective communication between these components is the key to achieving the goals of Industry 5.0, and the important parameters are shown in this article. The present work is focused on an overview and the impact of the futuristic subdivision of additive manufacturing applied to the fabrication of metallic parts/assemblies, more specifically, the 3D printing of challenging alloys or composites (such as copper alloys and/or composites with hard particles).

With the recent advancements in computational capacities and the widespread applications of machine learning in engineering problems, the role of numerical methods has been becoming more and more important to improve existing models or develop new models that can help researchers to better understand the underlying physics of combustion, their interaction with other physical phenomena such as turbulence, and their impacts on the performance of the related applications at both fundamental and practical levels [...]

This work reports a numerical investigation of microcombustion in an undulate microchannel, using premixed hydrogen and air to understand the effect of the burner design on the flame in order to obtain stability of the flame. The simulations were performed for a fixed equivalence ratio and a hyperbolic temperature profile imposed at the microchannel walls in order to mimic the heat external losses occurred in experimental setups. Due to the complexity of the flow dynamics combined with the combustion behavior, the present study focuses on understanding the effect of the fuel inlet rate on the flame characteristics, keeping other parameters constant. The results presented stable flame structure regardless of the inlet velocity for this type of design, meaning that a significant reduction in the heat flux losses through the walls occurred, allowing the design of new simpler systems. The increase in inlet velocity increased the flame extension, with the flame being stretched along the microchannel. For higher velocities, flame separation was observed, with two detected different combustion zones, and the temperature profiles along the burner centerline presented a non-monotonic decrease due to the dynamics of the vortices observed in the convex regions of the undulated geometry walls. The geometry effects on the flame structure, flow field, thermal evolution and species distribution for different inlet velocities are reported and discussed.