The present study undertakes a systematic review of the latest trends in sustainable manufacturing over the past five years, exploring future developments in technologies, methods, and strategies. Utilizing the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology, adapted to engineering, this research ensures transparency and reproducibility throughout the identification, screening, eligibility, and inclusion stages of the review process. A review of the extant literature identified several key terms that were frequently incorporated into research inquiries, including Industry 4.0, circular economy, additive manufacturing (AM), and the use of sustainable materials. The study’s main findings highlight the transformative role of digital technologies in fostering closed-loop systems and resource efficiency. For industry professionals, this signifies concrete prospects for enhancing operational efficiency, mitigating waste, and shifting towards more robust production models. Nonetheless, this review discloses persistent challenges, particularly for small- and medium-sized enterprises (SMEs). These challenges encompass elevated implementation costs and the intricacy of advanced digital solutions. The study’s findings indicate that while Industry 4.0 is a predominant catalyst for sustainable practices, its extensive adoption is impeded by substantial implementation costs and skill deficits. The study’s concluding remarks outline strategic directions for future research and policy, advocating for scalable, inclusive solutions to facilitate a global transition toward sustainable industrial systems.
Glass fiber-reinforced composites are widely used in industry, with machining operations frequently performed, drilling, in particular, for later assembly. Although there is a smaller increase in temperature during drilling in composites than in metals, further cooling of the tool can produce improvements in some variables, such as thrust force, diameter, or surface roughness. This has been seen in studies where lower temperatures were achieved by cooling compressed air, reaching around −20 °C in plates of polyether-ether-ketone and polyamide, reinforced with glass fiber at 30% (PEEK-GF30 and PA-GF30, respectively). This paper analyzes the results of cryogenic drilling in plates of PEEK-GF30 and PA-GF30, specifically assessing thrust forces, diameter, and average surface roughness. The experimental methodology was carried out by monitoring thrust forces during cryogenic drilling using a piezoelectric dynamometer, measuring diameters with a coordinate measurement machine, and assessing surface quality with a roughness profilometer. During the cutting, the temperature of the cutting tool achieved a temperature near −120 °C from cooling with liquid nitrogen. Conducting an analytical and statistical study allowed us to determine the relationships between the measured variables and cutting conditions. Our results showed that cooling the tool during the drilling processes improved results of the cutting process.
Additive manufacturing (AM) has rapidly evolved from a prototyping tool into an effective method for producing end-use components, thanks to its ability to produce complex, lightweight and customised parts. However, this technique requires a thorough understanding of the long-term behaviour and degradation mechanisms of components, especially when polymers are involved in the printing process. Unlike polymer components manufactured using traditional methods, polymers produced through AM exhibit unique microstructures, anisotropies, and interfacial characteristics due to the layer-by-layer fabrication process. These features can affect how these materials respond to thermal, mechanical and environmental stresses over time. Furthermore, technology-specific processing parameters directly govern porosity distribution, crystallinity evolution, interlayer bonding quality, and residual stress development, all of which are key factors for ensuring long-term performance. This review aims to support researchers in the development of durable additively manufactured polymer components by systematically analysing polymer degradation mechanisms, accelerated ageing and lifetime prediction methodologies. Following a PRISMA-based screening process, approximately 160 international standards relevant to polymer durability in additive manufacturing were selected from an initial corpus of about 620 documents for in-depth analysis. Processing–structure–property relationships specific to the AM processing of polymers, including the commonly used FFF (fused filament fabrication), SLA (stereolithography) and SLS (selective laser sintering), are examined in relation to crucial aspects for long-term structural integrity and degradation behaviour. Finally, limitations within the current normative framework are identified, emphasising the absence of process-aware durability assessment protocols and the need for dedicated standards tailored to additively manufactured polymer components.
20 February 2023 in The International Journal of Advanced Manufacturing Technology
Several tool wear models for machining operations have been reported in the literature. However, most of them are capable of modeling only a part of the wear curve, designed for quasi-linear curves or need to be fitted by means of differential equations. In this research, a new analytical easy-to-use wear model is proposed, taking into consideration the geometry of the cutting insert and the influence of the cutting speed and the tool-workpiece contact stress. In addition, the effect of the critical machining time, relative to the tool degradation, has also been introduced. The wear model describes completely the wear curve, from the initial rapid wear stage to the thermal-activated wear rate acceleration. The constants and parameters of the equation are determined by cutting experiments from the cutting forces and flank wear registers under a variety of technological parameters. This model has been validated for turning process on Ti48Al2Cr2Nb aluminide with uncoated carbide tool under different cutting conditions, varying the cutting speed and the geometrical position of the tool. It has been demonstrated its suitability to predict tool life, according to a defined wear criterion.