This review traces the evolution of low-density steels (LDS) and highlights the key mechanisms that link processing routes to microstructural evolution and performance. Beyond fabrication methods, the article emphasizes the fundamental insights that have emerged, particularly the roles of metal carbide/intermetallic network control, segregation mitigation, and grain refinement that govern the unique behavior of LDS across processing routes in achieving superior mechanical behavior. A key insight from the literature is the exceptional potential of mechanical alloying combined with spark plasma sintering to produce ultrafine and highly homogeneous LDS microstructures that are unattainable through traditional melting routes. The review also identifies the emerging role of near-net-shape casting and additive manufacturing as transformative technologies capable of overcoming longstanding challenges related to defects, compositional inhomogeneity, and geometric limitations. Overall, the review emphasizes that optimized processing strategies and parameter control will be crucial to enhance efficiency, unlocking superior mechanical properties and realizing the full lightweight potential of LDS in advanced engineering applications.

The hole expansion behavior serves as a key metric for assessing the formability of automotive structural components containing holes. With the growing emphasis on decarbonization in automotive manufacturing, hot-rolled steels have gained attention as promising substitutes for cold-rolled counterparts. Owing to their thermomechanical processing characteristics, hot-rolled steels frequently exhibit banded microstructures oriented along the rolling direction; however, the effect of these banded structures on hole expansion behavior remains insufficiently understood. In the present work, two hot-rolled steels with distinct banded morphologies were investigated under punching conditions in accordance with ISO 16630. The study focused on the evolution of microstructural features within the shear-affected zone (SAZ) and at the hole-edge surface before and after hole expansion. The findings indicate that the banded arrangement facilitates circumferential crack propagation along the hole edge, thereby improving hole expansion performance. This advantageous effect is particularly evident when the fracture zone constitutes a large fraction of the hole-edge surface, promoting stress relief through the generation of cross cracks. In contrast, when the fracture zone is limited, fracture initiation in the burr zone at the hole periphery leads to visible hole expansion cracks, contributing to the safe identification of failure during service. Additionally, the matrix hardness and strength were found to play a decisive role in governing hole expansion behavior, with a positive correlation established between edge hardening induced by punching and the hole expansion ratio.

For processing the difficult-to-cut materials, TiAlSiN coatings have been widely applied to machining tools. Pulse magnetic field treatment, as a novel, fast, and environmentally friendly post-treatment method, can directly modify the finished TiAlSiN-coated tools without causing physical damage. This study investigates the wear resistance of pulse magnetic field-treated TiAlSiN-coated carbide samples under both dry and lubricated friction conditions. Results show that pulse magnetic field-treated TiAlSiN-coated samples exhibit improved wear resistance and friction reduction in both friction environments. In dry friction conditions, the coating's coefficient of friction decreased by 13.73%, resulting in a more stable friction process. In lubricated conditions, the coefficient of friction decreased by 23.46%. Due to the effects of the pulse magnetic field, the hardness of the coating and substrate increased by 6.58% and 3.7%, respectively. The bonding phase Co in the carbide substrate exhibited phase transformation and increased defect density, such as dislocations. These changes enhanced the bonding strength at the coating/substrate interface, thereby improving its mechanical performance and tribological behavior.

The field of abrasive waterjet (AWJ) machining has seen growing interest over the past decade, reflected in the increasing number of related research publications. Despite significant progress, uncertainties remain regarding the future direction and performance of AWJ technology. This paper aims to deliver a structured, in-depth, dynamic, quantitative, and objective analysis of research in the abrasive waterjet field. By examining the existing body of knowledge and identifying emerging trends, this review seeks to enhance and refine research within the domain of manufacturing. This study employs bibliometric and text mining analyses using R-tool Biblioshiny and VOSviewer to quantitatively assess and visualize key concepts, themes, and research dynamics in AWJ. The dataset, sourced from the Scopus database (1980–2023) following PRISMA guidelines, includes 1,666 articles from 504 sources, involving 3,062 authors across 80 countries and 2,776 affiliations. Findings reveal a significant growth rate of 228.57% in AWJ-related publications in 1993, marking a pivotal increase in scientific output. India and China emerged as the most productive countries in AWJ research. The results provide valuable insights for academics and policymakers, offering a benchmark for evaluating research efforts and guiding future developments in AWJ technology.

Material selection is a complex challenge within Multi-Criteria Decision-Making (MCDM). This research introduces SIWEC-ROC, a novel two-stage weighting method combining SIWEC and ROC to ensure stable material rankings across various MCDM techniques. The method first employs SIWEC to determine initial criterion weights and ranks, then applies ROC to calculate final weights based on these ranks. Validated across four mechanical engineering cases, including weighting for ranking gear materials, cutting tool materials, automotive protective plate materials, and EDM powders, SIWEC-ROC consistently demonstrated superior ranking stability compared to SIWEC alone. For example, average Spearman coefficients significantly improved: Case 1 showed 0.9563 for both SIWEC and SIWEC-ROC, Case 2 from 0.8368 to 0.9114, Case 3 from 0.8167 to 0.8667, and Case 4 from 0.8869 to 0.9212. The advantages of SIWEC-ROC over SIWEC were even clearer during sensitivity analysis. Using SIWEC-ROC allows engineers to quickly identify optimal materials, saving time, effort, and cost by reducing trial machining and boosting overall efficiency.

In response to the problem of lubrication failure of sliding bearings in circular arc gear pumps under variable operating conditions, this paper studies the lubrication characteristics of sliding bearings. Establish a fluid lubrication model for sliding bearings and introduce radial forces and Reynolds boundary conditions. Analyzing the influence of rotational speed and outlet pressure of circular arc gear pump on the lubrication characteristics of sliding bearings based on finite difference method. The research results indicate that as the rotational speed increases, the minimum film thickness gradually increases, the maximum film pressure gradually decreases, and the position of the dynamic pressure effect gradually shifts forward. The maximum film pressure position and the minimum film thickness position differ by about 0.4 rad in the circumferential direction. The acceleration curve has a significant impact on the lubrication characteristics of sliding bearings, and the greater the acceleration, the more obvious the changes in lubrication characteristics. Compared with the acceleration process, the changing trend of lubrication characteristics of sliding bearings during the boosting process is opposite.

Assessing and predicting formability of a material have significant importance for forming process design and optimisation. In this paper, formability of AA6082 under various conditions were investigated through biaxial tensile tests, and the results were used for calibrating a set of constitutive equations based on continuum damage mechanics (CDM). Forming tests that replicate industrial forming conditions were conducted to explore the effects of HFQ conditions on the formability of the AA6082 aluminium sheet. In these tests, B-pillar components of a commercial vehicle were produced under different conditions, followed by ARGUS measurements to capture the formed geometry and strain distributions. The CDM-based constitutive equations were implemented into FE model to simulate the forming processes, and the simulation results were compared with experimental data to validate the model. It was found that lower forming speed and higher temperature lead to higher formability of the material and are beneficial to the quality of the formed components. Numerical simulations successfully predicted the strain distribution and defects formed during forming and showed good agreements the experimental results from the B-pillar forming tests, indicating that the CDM-based model can be successfully applied in practical forming processes for designing and optimising the process parameters.

This paper systematically reviews literature related with digital supply chains (DSC) and investigates the application status and development trend of different digital technologies in supply chain management. The review is conducted from the perspective of seven key digital supply chain technologies, i.e. Internet of Things (IoT) & Radio Frequency Identification (RFID), 5th Generation Mobile Communication Technology (5G), 3D Printing, Big data (BD), Blockchain, Digital Twins (DT), and Intelligent autonomous vehicles (IAVs). It highlights the main limitations and opportunities of the various DSC technologies, provides an overview of prior studies, and identifies knowledge gaps by outlining the advantages, weaknesses and restrictions of individual technology. The paper also aims at providing a development framework as a roadmap for the match of different digital technologies with different strategic goals.

Compared to traditional processing techniques, laser additive manufacturing technology has advantages such as short processing cycles, no molds, and is not limited by complex structures. However, the forming quality of GH3625 nickel-base alloy metal parts is affected by various process parameters, in which the distribution characteristics of laser beam energy density, microstructure and mechanical properties play a key role. In order to investigate the influence of beam energy density distribution on the main properties of GH3625 nickel-based alloy metal parts, the beam energy density distribution was changed by controlling the defocusing amount. Then it sets 5 different defocusing parameters to obtain the corresponding energy density distribution characteristics. Observing and analyzing the various properties of alloy powder from the perspectives of different scanning speeds, laser power, and energy density distribution characteristics. The results show that when the laser power is 600 W, the scanning speed is 700 mm/min, and the energy density distribution is characteristic 4, the metal parts have the best performance. Its density is 99.90%, microhardness is 350.44 HV, tensile strength is 1328 Mpa, friction coefficient is about 0.51, and wear rate is 0.55%. This indicates that the laser additive forming method proposed in this study can effectively improve the hardness, density and other properties of GH3625 nickel-based alloy metal parts to achieve the best state, which provides an important reference for the further optimization of the material preparation process.

Platinum Group of Metals (PGMs) has been at the forefront of emission control in autocatalysts and could be the driving force behind the net-zero agenda, by providing emission-free energy sources. The literature has revealed that the versatility of additive manufacturing (AM) could be used to produce intricate hierarchical structures that increase the active catalytic sites of PGMs in autocatalysts, fuel cells (FCs), and batteries with improved operational efficiency. FCs and batteries with lower PGM loads have proven to perform better than conventional manufactured energy devices with higher PGM loads. The inherent hyperlocal-on-demand nature of AM could be used to disrupt the conventional multiple energy-consuming carbon-intensive supply chain to decarbonize the atmosphere. The synergy between AM and PGMs has contributed greatly to the increase in operational performance of FCs and batteries, compelling several nations to start migrating their energy systems to eco-friendly energy systems.