International Journal of Lightweight Materials and Manufacture最新文献

Production techniques used in processing alloy and composite materials have the propensity of improving their properties or deteriorating them. Therefore, appropriate choice of processing routes is a prerequisite for the development of top-notch high entropy alloys (HEAs). The types and forms of phase(s) developed in HEAs are also influenced by the processing technique. Incidentally, their properties are influenced by the phases present. So, the aim of this study was to investigate the characteristics of phases present in HEAs, and how they affect their properties and applications. More so, to investigate the processing techniques used in the development of HEAs and their influence on their properties and applications. The resource materials were sourced from Scopus database and google scholar website of articles published in the last ten years, laying more emphasis on the most recently published works. In the study, it was discovered that formation of the phases was dependent on: was dependent on: the type of the production process, present elements and the employed processing parameters. Hence, it was concluded that optimization of processing parameters and careful selection of elements are the key factors to develop HEAs of reputable properties.

A study was carried out to investigate and enhance the effects of friction stir welding on the mechanical characteristics of a flange composed of 6061-T3 aluminum alloy. The pipes possess an outer diameter and wall thickness of 6 mm, while the plates are sized at 100 x 100 × 6 mm. Nine unique experiments were planned using the Taguchi orthogonal array method, with the welding tool remaining constant. Three independent variables (travel speed, rotation speed, and shoulder diameter) were altered at three different levels for each variable. The research analyzed the influence of various FSW factors on the weld flange joint. Analysis of variance (ANOVA) and grey relational analysis (GRA) were employed to determine the impact of each FSW underwater parameter. Moreover, the statistical Taguchi technique (TM) was used to predict the optimal combination of welding parameters to improve tensile properties, including tensile strength (UTS), yield strength (YS), elongation (EI%), and bending load (BL) of welded joints. Additionally, the actual tests demonstrated a high level of agreement with the results obtained from the proposed mathematical model. The validation results obtained indicate that the optimization method is a dependable tool for enhancing the quality responses of friction stir welding.

A novel approach to enhancing the efficacy and surface quality of magnetic polishing involves the incorporation of a magnetic liquid circulation system for abrasive particle regeneration in conjunction with a circular Halbach array. The continuous renewal of abrasive particles within the polishing zone is realised through a conveyor belt that transports new abrasive particles into the polishing liquid solution. This formation of a continuously circulating polishing system ensures uninterrupted magnetic finishing processes and maintains stability throughout the polishing operation. This study extensively explores polishing force distribution, magnetic field distribution and abrasive grain behaviour in the polishing area facilitated by the magnetic liquid solution. The application of the proposed polishing processes to polymethyl methacrylate, an optical lens material, aims to comprehend the characteristics and validate the feasibility of the polishing method. Key influencing factors in the magnetic polishing process, including abrasive grain size, magnetic particle, polishing distance and conveyor speed to surface quantity, are examined through experimental analysis. Results of the experimental polishing processes demonstrate that the utilisation of circular Halbach arrays with circulating abrasives produces a nanometric surface finish. Even in the polishing of polymethyl methacrylate with an initial rough surface (Ra = 464.895 nm), the process achieves an ultra-fine level with Ra below 9 nm without disruption in the material polishing processes of optical lenses.

This paper offers a comprehensive overview of recent advancements in digital twin technology applied to additive manufacturing (AM), focusing on recent research trends, methodologies, and the integration of machine learning. By identifying emerging developments and addressing challenges, it serves as a roadmap for future research. Specifically, it examines various AM types, evolving trends, and methodologies within digital twin frameworks, highlighting the role of machine learning in enhancing AM processes. Ultimately, the paper aims to underscore the significance of digital twin technology in advancing smart manufacturing practices. A total of 133 papers were identified for analysis through IEEExplore, ScienceDirect, Web of Science, and Google Scholar and web resource. Approximately 74% of the papers are journals and 21% are conferences and proceedings. Moreover, 78% of the journal papers were Q1 journals. The paper identifies the potential benefits of digital twins at different levels, the existing problems associated with implementing digital twin in additive manufacturing, recent advancements, the existing approaches, and the framework. This review provides a comprehensive overview of the current landscape of research in digital twin technology for additive manufacturing, utilizing the latest resources to identify cutting-edge developments and methodologies. Through an exploration of potential benefits and implementation challenges, the review offers valuable insights to researchers and practitioners in the field. Additionally, it contributes to the discourse by offering a nuanced discussion on future research directions, paving the way for further advancements.

Laser peen forming (LPF) is an appealing technique for forming metal sheets using high-energy, short-duration laser pulses. The deformation of the target metal plate is closely related to the magnitude and distribution of laser-induced residual stress. Consequently, the relationship between process parameters and residual stress is worth researching. In this research, two process parameters in LPF, laser energy and coverage ratio (spot distance essentially), and one workpiece parameter, plate thickness, were examined through an element method (FEM) of multiple square-spot laser shock peening (SSLSP). Corresponding experiments of SSLSP on aluminum alloy 2024-T351 test blocks were conducted, together with an X-ray diffraction (XRD) residual stress measurement and a surface morphology observation. The FEM simulation and experimental results show that congested laser spots had a significant influence on the magnitude of compressive residual stress; higher laser energy was beneficial to the depth of the compressive stress layer but could decrease its magnitude. Therefore, for better forming ability, higher laser energy and a higher coverage ratio are beneficial; for surface strengthening, laser energy should not be too large, and the coverage ratio should be larger than 100% to ensure that the residual stress on the treated surface is compressive, resulting in better surface integrity.

There is a real demand for sustainable lightweight structures because of the growing environmental concerns. One important solution is developing structures through recycled scrap/waste thermoplastic materials. The current work studies the friction stir spot weldability of recycled thermoplastics, which will help to analyze the potential of friction stir-based welding techniques towards developing these sustainable structures. The combined behavior of recycling-welding procedures is investigated, as they may cause degradations; to ensure that the base thermoplastic polymer's chemical, thermal, and mechanical properties are retained. Scrapped milk bottles made from HDPE material are used as a case study. The highest lap-shear load of 1528 N was achieved at the optimum welding conditions of 1600 rpm rotational speed, 1 mm plunge depth, and 60 s dwell time. Fractographic studies (macroscopic and SEM-based) suggested four types of fracture morphologies depending on welding conditions used. The DSC results showed no significant differences in melting temperature and crystalline content of the polymeric material. The TGA tests showed no significant thermal degradations. The FTIR analysis of all the samples (bottle, recycled sheet, weld material) exhibited characteristic HDPE peaks. All these results suggest combined-welding recycling had a minimal impact on the polymeric structure. Thus, friction stir spot welding (FSSW) technique joins recycled thermoplastic scrap/waste materials with high lap-shear load and without any significant polymer degradations.

This paper proposes an innovative multi-scale method for determining gas pressure parameters of superplastic forming, which is based on the quantitative relationship between the grain growth mechanism and fracture mechanism of Ti–6Al–4V alloy. The high-temperature tensile tests were conducted on the material at temperatures ranging from 700, 800, 840, 890, 920, and 950 °C, strain rates were selected as 10⁻²∼10⁻⁴/s. The grain size measurements were observed using electron back-scatter diffraction (EBSD). Particularly, the relation between grain size changes and fracture behaviour is specifically discovered using a physically-based dynamic material model (DMM), and the grain size thresholds for each forming limit are proposed. The physical fracture mechanism is named the “Grain growth based fracture (GGBF)” mechanism. Furthermore, an innovative method based on the GGBF mechanism is proposed to design the superplastic forming loading, and practical four-layer hollow structures experiments are applied to validate the fracture mechanism in superplastic forming. In total, A superplastic forming GGBF mechanism has been verified, and it is expected to be helpful for shape and property control in the forming process of complex structures.

Current advancements in technology enables the enhancement and refinement of alloys to address the demands of expanding industrial applications. High Entropy Alloys (HEAs) are a developing class of alloys displaying unique and advanced mechanical, tribological, thermal stability, and corrosion properties. HEAs have unpredictable structures and compositions displaying enhanced performance and characteristics. Unique microstructures can be achieved through multi-principal elements and HEAs usually outperform conventionally made alloys. Lightweight HEAs (LWHEAs) are a category of HEAs with alloy density less than 6 g/cm³ and are potentially applicable in the automobile and aerospace industries. The superior characteristics make LWHEAs an extremely interesting space for research. Recent research has focused on effective manufacturing methods for processing alloys, coatings, and surface modifications. The current work discusses a comprehensive review of fabrication processes, mechanical, tribological, and corrosion behavior of LWHEAs. The review also highlights the future scope of research and directions for designing LWHEAs. The results of the article provide crucial information to researchers and pioneers exploring LWHEAs.