Fused Filament Fabrication (FFF) is a widely adopted additive manufacturing technique, yet its mechanical performance is highly dependent on process parameters, particularly nozzle diameter and printing speed. This study evaluates the influence of these parameters on the tensile behavior of Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA), aiming to determine optimal conditions for enhanced strength. ASTM D638-Type IV specimens were printed using nozzle diameters ranging from 0.05 to 0.25 mm and speeds from 15 to 80 mm/s. For ABS, tensile strength increased from 56.46 MPa to 60.74 MPa, representing a 7.6% enhancement, as nozzle diameter increased, with the best performance observed at 0.25 mm and 45 mm/s, attributed to improved melt flow and interlayer fusion. PLA exhibited a non-linear response, reaching a maximum strength of 89.59 MPa under the same conditions, marking a 22.3% enhancement over the minimum value. The superior performance of PLA was linked to optimal thermal management that enhanced crystallinity and interlayer bonding. Fractographic analysis revealed reduced porosity and smoother fracture surfaces under optimized conditions. Overall, PLA consistently outperformed ABS across all settings, with an average tensile strength advantage of 47.5%. The results underscore the need for material-specific parameter tuning in FFF and offer practical insights for optimizing mechanical performance in applications demanding high structural integrity, including biomedical, aerospace, and functional prototyping.

This article explores the fatigue characteristics of acrylonitrile butadiene styrene (ABS) components fabricated using fused filament fabrication (FFF) additive manufacturing technology. ABS is frequently used as a polymeric thermoplastic material in open-source FFF machines for a variety of engineering applications. However, a comprehensive understanding of the mechanical properties and execution of FFF-processed ABS components is necessary. Currently, there is limited knowledge regarding the fatigue behavior of ABS components manufactured using FFF AM technology. The primary target of this study is to evaluate the results of part-build directions and build orientation angles on the tensile fatigue behavior exhibited by ABS material. To obtain this target, an empirical investigation was carried out to assess the influence of building angles and orientation on the fatigue characteristics of ABS components produced using FFF. The test samples were printed in three distinct directions, including Upright, On Edge, and Flat, and with varying orientation angles ([0°, 90°], [15°, 75°], [30°, 60°], [45°]), using a 50% filling density. The empirical data suggest that, at each printing angle, the On-Edge building orientation sample exhibited the most prolonged vibrational duration before fracturing. In this investigation, we found that the On-Edge printing direction significantly outperformed the other orientations in fatigue life under cyclic loading with 1592 loading cycles when printed with an orientation angle of 15°–75°. The number of loading cycles was 290 and 39 when printed with the same orientation angle for the Flat and Upright printing directions, respectively. This result underscores the importance of orientation in the mechanical performance of FFF-manufactured ABS materials. These findings enhance our comprehension of the influence exerted by building orientation and building angles on the fatigue properties of FFF-produced test samples. Moreover, the research outcomes supply informative perspectives on the selection of building direction and building orientation angles for the design of 3D-printed thermoplastic components intended for fatigue cyclic-loading applications.

This study investigates the friction stir welding (FSW) of aluminum alloy 7075-T651, mainly focusing on managing heat generation during the process. The critical parameters influencing heat amount and the material flow including FSW tool shoulder diameter (SD) and travel speed (TS) were investigated. Two far different SD of 10 mm and 20 mm with constant pin diameter (PD) of 5.70 mm that resulted in PD: SD ratios of 1:1.75 and 1: 3.50, respectively, were employed. Furthermore, three different travel speeds of 25, 50, and 75 mm min⁻¹ at a constant rotation rate of 600 rpm were used in combination with the two PD: SD ratios. The macrographic and radiographic results indicated that the smallest PD: SD ratio has successfully achieved sound friction stir welded (FSWed) joints for the same travel speeds. Results also indicated that a significant amount of material deformed under a high PD: SD ratioat a high TS of 75 mm min⁻¹, while flash increased with reducing PD: SD ratio.Mechanical properties were compared, revealing that hardness in the nugget zone (NZ) decreased with a lower TS of 25 mm min⁻¹. A small PD: SD ratioallowed for more symmetrical heat distribution, supported by the hardness map. The ultimate tensile strength decreased with increasing TS, and the highest ultimate strength, reaching 319 MPa, was observed with a 1:1.75 ratio and TS of 25 mm min⁻¹. X-ray diffraction analysis (XRD) found an increase in peaks with increasing shoulder diameter and the number of peaks increased with decreasing travel speeds.

The mechanical properties of the polymeric samples were discussed in many papers. Only several of them investigates the mechanical properties of the 3D-printed sampled prepared by different technologies, i.e. FDM, FFF, MJM, SLA, SLS etc. More dense samples could be obtained by any art of SLA technology, for example, based on the DLP principles, whereby less dense samples made of any thermoplastic materials obtained by FFF technology. In the current paper the authors carried out, firstly, experiments and numerical simulation of the tensile and compression tests of the 3D-printed samples made of ABS and PLA polymers. The initial CAD-model does not contained any topological information to the samples’ surface. Secondly, the same simulation runs but for CAD-model obtained by 3D-scanning were performed with respect to the surface appearance. The density of the material was taken as a goal function. And, thirdly, at the end the experimental and numerical results were compared. The deviation of the deformation forces between the numerical and experimental results for as-modelled in CAD and as-scanned samples was arranged within the 5 – 10% and strongly depended on the inner type of infill, represented by porosity coefficient.

The clay brick industry, a cornerstone of global construction, faces increasing pressure to mitigate its substantial environmental footprint and improve the sustainability of its practices. The energy-intensive firing process, often reliant on coal combustion, generates significant atmospheric emissions, contributing to climate change and local air pollution. Furthermore, achieving desired mechanical properties in the final product is essential for ensuring the structural integrity and longevity of buildings. This review provides a comprehensive analysis of the chemical and thermodynamic processes governing clay brick firing, exploring their influence on both emissions and the final product's mechanical strength, durability, and water absorption. We examine the key chemical transformations of clay minerals during firing, including dehydration, decarbonation, oxidation, and vitrification, and analyze the combustion reactions of various fuels, including coal, biomass, natural gas, and alternative fuels. We present a comparative evaluation of diverse kiln technologies, ranging from traditional intermittent kilns (e.g., clamp, downdraft) to more efficient continuous kilns (e.g., FCBTK, Hoffman, tunnel, VSBK, zigzag), emphasizing their energy consumption, emission profiles, and impact on the mechanical properties of the fired bricks. The review also explores strategies for enhancing sustainability in the brick industry, including adopting cleaner fuels, optimizing kiln operations and implementing best practices, utilizing hybrid systems, and incorporating industrial and agricultural waste materials. We discuss the significant role of regional contexts, socioeconomic factors, and policy interventions in promoting sustainable practices. Finally, we underscore the importance of life-cycle assessments for evaluating the full environmental impact of brick production, from raw material extraction to building demolition and material recycling and highlight key areas for future research to advance sustainable brick manufacturing practices globally.