Open Access
Review
13 June 2025Advances in Sintering Technologies for SiC Ceramics: Mechanisms, Challenges, and Industrial Applications
Silicon carbide (SiC) ceramics have become critical materials for high-temperature engineering applications because of their exceptional mechanical strength, thermal conductivity, and chemical stability. In order to meet the diverse needs of industrial applications, various sintering methods have been developed. These include traditional methods such as pressureless sintering, reaction-bonded sintering, hot pressing, and recrystallization, as well as advanced technologies like spark plasma sintering, oscillatory pressure sintering, and flash sintering. This review provides a systematic analysis of both traditional and advanced sintering techniques for SiC ceramics. It highlights their mechanisms, critical process parameters, and impacts on the final material properties. Key challenges, including high sintering temperatures, additive selection, microstructural control, and scalability, are examined. Strategies for balancing cost-efficiency with performance are also discussed. In addition, recent advancements in SiC-based composite materials for applications ranging from aerospace components to catalytic filtration systems are presented. Finally, future research directions are proposed. These focus on precise additive engineering, microstructure tailoring, and innovative sintering methodologies to speed up the transition of high-performance SiC ceramics from laboratory prototypes to large-scale industrial implementation.
Open Access
Review
19 June 2025Research Progress on High-Entropy Fibrous Materials
Due to their lightweight, high strength, and thermal resistance, HEFMs exhibited significant potential in aerospace, energy storage, environmental protection, and defense. This review systematically presented the research progress on high-entropy fibrous materials (HEFMs), covering their fundamental concepts, fabrication methods, crystal structure characteristics, performance advantages, and application fields. The different crystal structure types and fabrication techniques of high-entropy ceramic fibers and high-entropy alloy fibers were discussed. Additionally, the mechanical property advantages of HEFMs and their applications in thermal insulation materials, catalysis, and energy storage were analyzed. Finally, the current challenges in HEFM research and provide an outlook on future development directions.
Open Access
Article
20 June 2025Optimization of Powder Distribution and Feeding Efficiency Using an Annular Powder-Feeding Nozzle: A Numerical and Experimental Study
The quality of spherical powders required in plasma spheroidization is particularly important to advanced manufacturing, such as additive manufacturing and thermal spray coatings. Traditional powder feeding systems, such as radial and coaxial nozzles, often suffer from suboptimal powder distribution, low powder capture efficiency, and poor control of particle trajectories. These issues deteriorate spheroidization quality and material efficiency. We propose here an innovative annular powder-feeding plasma torch for these challenges and to optimize the powder-feeding dynamics. The novel nozzle consists of a tangential powder feeding mechanism and a concentric conical structure that provides uniform powder distribution and minimizes plasma jet interference. Computational fluid dynamics (CFD) simulations and Discrete Phase Modeling (DPM), combined with a literature review, are used to study such as throat size and convergent-divergent profiles of nozzles for gas-powder interactions. Yttria-Stabilized Zirconia (YSZ) powder was used for the experimental validation of the annular nozzle; the annular nozzle was found to outperform traditional nozzles in this application with a powder capture efficiency of 75%, a deposition efficiency of 92%, and a spheroidization efficiency of 85%; 85% of the particles had a circularity index >0.9. These results indicate that powder distribution uniformity, deposition efficiency, as well as spheroidization quality are greatly improved than those from conventional plasma spheroidization systems, demonstrating the potential for better process performance for plasma spheroidization. These findings demonstrate the relevance of the optimized annular nozzle in the field of high-value material manufacturing as it yields increased coating quality and minimized material wastage.
Open Access
Article
01 July 2025Experimental and Numerical Study of Formation Mechanism of Dual-Phase (AlCoCrFeNi)X HEAs Brazed Joints by Reactive Ni/Al Nano-Multilayers
The FCC + BCC dual-phase solid solution structure was obtained in the Al0.1CoCrFeNi/304SS brazed joints using Ni/Al reactive multilayer nano-foils, which was proved by combining experiments with simulation. In this study, Finite Element Analysis was achieved to analyze the diffusion behavior across brazing joints, which were subsequently interrelated with the formation mechanism of the brazed micro-structures during the brazing process. During brazing, the joint interface is tightly bonded, and the atoms are diffused sufficiently to form the solid solution zone. The representative microstructure of the joint mainly comprised hard BCC (Al-Ni) + ductile FCC (Co-Fe-Cr) dual-phase. The successful use of nano-multilayer foils as a HEAs filler design can broaden the application range of HEAs and provide a novel procedure for brazing 304SS and Al0.1CoCrFeNi HEAs, and developing a novel field in the manufacture of HEAs-related joints.
