Grain refinement and subsequent amorphization can be realized in Sm-Co alloys using high-energy ball milling (HEBM). In this study, an amorphous-nanocrystalline exchange-coupled SmCo6.3Cu0.7 alloy was prepared using HEBM, and the alloy was systematically studied using X-ray diffraction and transmission electron microscopy to explore the extent to which the HEBM time influences the alloy's phase structure and magnetic properties. The results show that the as-cast alloy has poor magnetic properties, with a coercivity of 1017.4 Oe and remanence of 9.8 emu/g. Grain refinement and amorphization as a result of HEBM led to the formation of an amorphous nanocrystalline composite structure with significantly enhanced magnetic properties—a peak coercivity of 7730.6 Oe and a peak remanence of 40.8 emu/g. Our findings provide new insights into preparing high-performance amorphous-nanocrystalline permanent magnet alloys.
Fossil fuels are ancient life, and the nitrogen they contain—preserved from the proteins and cells of herbal and other buried life matter that lived millions of years ago—is now returning to Earth as fertilizer, enabling new plant growth. This stoichiometric link explains the long-ignored “missing sink” in global carbon budgets and shows that 44
The pursuit of lightweight and sustainable structural materials has accelerated the development of hybrid natural fiber-reinforced polymer composites. This study develops hybrid epoxy composites reinforced with Albizia saman (rain tree) and pineapple leaf fibers (PALF), with emphasis on the combined effects of fiber loading and hybrid ratio on mechanical properties, dry sliding wear, and moisture uptake. The composites were fabricated by controlled mechanical mixing, vacuum degassing, compression molding, and post-curing using total fiber loadings of 20–40 wt.
To enhance the comprehensive performance of the metal hollow sphere composites, Fe26Ni26Al26B11W11 high-entropy alloy (HEA) powder was fabricated by mechanical alloying, and the corresponding hollow spheres (HSs) were prepared via the template removal method. Subsequently, the physical parameters of the HSs were directly measured. HEA powders and HSs were characterized by XRD, SEM, and TEM, while the compressive properties of the HSs were evaluated on a universal testing machine. The results showed that the diameter and wall thickness of the HSs decreased after sintering, while the HS apparent density and wall density increased. Microstructural analysis showed that the HEA powders comprised Fe26Ni26Al26B11W11 solid solution with a body-centered cubic (BCC) structure. In contrast, the walls comprised hexagonal WB2 phase, along with three BCC-structured solid solutions. Compression test results showed that the HSs underwent brittle fracture, with a maximum load of 350 ± 8 N and a corresponding displacement of 0.13 ± 0.05 mm.
