The poor thermal stability of metallic copper limits its applications. This study fabricated graphene-encapsulated fine-grained copper composites via chemical vapor deposition (CVD) and investigated graphene growth on fine-grained copper (about 1 μm diameter). Results showed that pure copper's grain size increased from 2.03 μm (600 ℃) to 18.2 μm (1000 ℃), with hardness decreasing from 91.56HV to 27.64HV. Interestingly, graphene-encapsulated composites maintained stable grain size distribution (1.25~1.35 μm) and hardness distribution (83.96~100.63HV) across the different temperatures. These findings demonstrated that the graphene encapsulation on fine-grained copper significantly enhanced thermal stability by inhibiting copper atom diffusion. Furthermore, the drawn composite wires fabricated from the graphene-encapsulated copper composites by annealing at 1000 ℃ showed a 53.9% increase in hardness, a 12% improvement in tensile strength, a 29.8% higher elongation, and a 6.8% reduction in electrical resistivity compared with the counterpart produced from pure copper. This work provided new insights for fabricating copper-based composites with superior thermal stability.

CuS nanoparticles have attracted extensive attention in many fields due to their unique optical, electrical and catalytic properties. This review systematically reviewed synthesis methods, physical properties, and applications of CuS nanoparticle materials in various fields. Firstly, the basic principles and research progress of three main synthesis methods of CuS, including water/solvothermal method, chemical precipitation method and microwave-assisted method, were systematically summarized, and the advantages and disadvantages of each method were summarized. Secondly, the unique optical, electrical, catalytic and biocompatibility of CuS nanoparticles stemmed from the crystal structure of CuS nanoparticles were introduced. Furthermore, the research progress in fields of biomedicine, environment and supercapacitors based on their unique physical properties were summarized. Applications in photothermal therapy, drug delivery carriers, organic pollutant degradation and supercapacitor electrode materials were mainly discussed. Finally, the challenges faced by development of CuS nanoparticle materials in various fields were summarized, and future research directions were prospected. It was pointed out that optimizing synthesis method and deep understanding of properties are key factors in effective applications of the materials. CuS nanoparticle materials were expected to play a greater role in future scientific research and industrial applications. This review provided some references and inspirations for promoting the in-depth research and wide application of these materials in various fields.

Recycling and reuse of copper alloys constitutes a crucial component in China's copper alloy production. During the recycling of brass, iron (Fe) is a prevalent impurity element that can significantly impact brass properties, thus necessitating stringent limitation of iron in brass. This study achieved precise control of Fe content during brass recycling by regulating the input of recycled materials, and systematically investigated the influence of iron on microstructure and properties of recycled H65 brass. Results demonstrated that with increasing Fe content in brass, grains were significantly refined, and the ultimate tensile strength, yield strength and plasticity increased. However, this led to a decrease in elongation and electrical conductivity. Specifically, as Fe content increased from 0.014% to 0.051%, the average grain size decreased from 64.2 μm to 48.9 μm, yield strength increased from 105.9 MPa to 122.1 MPa, and hardness increased from 74.5 HV to 88.1 HV. Conversely, elongation decreased from 62.6% to 54.5%, and electrical conductivity decreased from 27.5%IACS to 25.8%IACS. On the other hand, electrochemical tests revealed that the average corrosion rate exhibited an initial decrease followed by an increase, indicating corrosion resistance initially improved but subsequently deteriorated with increasing Fe content. When Fe content was below 0.04%, solid solution strengthening predominated. Further increases may lead to elemental segregation or even precipitation. This research offered systematical guidance for optimizing economic benefits, controlling microstructural evolution, increasing corrosion resistance, and improving processing performance of recycled brass.

Currently, copper-based composites have been widely applied in various fields. With advancement of science and technology and continuous improvement of material requirements, preparation of copper-based composites with high strength and high conductivity has become a current research focus. Carbon nanomaterials (CNMs), due to their excellent properties, have been widely studied by researchers as reinforcing phases in copper-based composites. This paper demonstranted an in-depth study and analysis of three representative CNMs/Cu composites: carbon nanotube (CNT)/Cu, graphene (GR)/Cu, and carbonized polymer dot (CPD)/Cu. When these three CNMs are used as reinforcing phases, they generally have problems such as prone to agglomeration and poor interface bonding with Cu, which leads to a decline in the performance of the composites. Focusing on research difficulties and disadvantages of such materials, similarities and differences in performance of each composite were analyzed and discussed based on intrinsic structural characteristics of the materials. Preparation methods, mechanical properties, electrical properties, and strengthening mechanisms of copper-based composites reinforced by introduced phases were studied. This provided inspirational ideas on preparation and performance research of copper-based composites reinforced by CNMs, breaking through the existing technical bottlenecks and realizing controllable preparation of copper-based composites with high strength and high conductivity.

Ceramic particle reinforced copper matrix composites have demonstrated broad application prospects in fields such as electronic packaging, aerospace, and rail transportation owing to their outstanding comprehensive properties. Incorporation of ceramic particles not only significantly enhances strength, hardness, and wear resistance of the copper matrix but also largely preserves its excellent electrical and thermal conductivity. In recent years, with the continuous advancement of fabrication technologies and characterization techniques, understanding of interfacial structures and interaction mechanisms between ceramic particles and the copper matrix has deepened considerably. Current research efforts mainly focus on precisely optimizing processing parameters and rationally designing the type and distribution characteristics of the reinforcing phases to maximize strengthening effects of ceramic particles within the copper matrix. Therefore, this review systematically summarized fabrication methods (internal oxidation, mechanical alloying, reactive spray deposition, powder metallurgy, additive manufacturing, stirring casting) of ceramic particle reinforced copper matrix composites. Influence of ceramic particle characteristics (type, content, particle size, interface bonding) on composite performance was analyzed. Electrical conduction and strengthening mechanisms were elucidated. Finally, existing challenges and future research directions were discussed, aiming to provide valuable insights for the further development and practical application of high-performance ceramic particle reinforced copper matrix composites.

This study aims to investigate the influence of Mg addition on the microstructure and properties of C19400 alloy, providing a potential approach for performance enhancement. To this end, C19400 alloys with varying Mg contents were fabricated under identical processing conditions, and then the alloys with different Mg contents were processed by thermomechanical treatment. Microstructure, mechanical properties, electrical conductivity, softening temperature, and bending performance of the alloys in different processing states were examined. Results revealed that Mg addition suppressed the precipitation of secondary phase, leading to a finer and more homogeneous dispersion. Under the same deformation and heat treatment conditions, tensile strength and hardness of the alloys increased with Mg content. Moreover, Mg-containing C19400 alloys exhibited superior high-temperature softening resistance, with the softening temperature reaching 490 ℃. Bending performance of Mg-containing C19400 alloys was significantly improved compared with the Mg-free alloys with the same thickness.

With the growing emphasis on environmental protection, discharge standards of chemical oxygen demand (COD) for smelting wastewater have also been continuously raised. In response to the problem that COD in drainage from a certain process in a copper smelting plant fluctuated between 50 and 100 mg/L, the sources of COD in drainage were traced by examining COD variation patterns of water samples in the technical process. In addition, properties of influent water samples, such as composition, COD variation patterns and contribution to the COD of the day, were analyzed. Traceability of COD throughout the process facilitated the source management and control of COD. Results showed that COD in drainage was correlated with that in the neutralization water in the technical process. COD in the neutralization water was mainly from six types of influents. Among them, wastewater from the first acidification stage (influent water ①), the second acidification stage (influent water ②), and the material preparation process (influent water ③) was main contributor to the amount of COD of the day. Considering that COD in drainage was mainly indicated as organic matter, high-performance liquid chromatography was used to identify pollutant source. It was found that organic components in drainage were related to influent water①, ②, and ③. It could be inferred that COD in drainage mainly originated from the three influents. Influent water①, ②, ③ and their mixture were treated by oxidation using YJY-O-1, resulting in 40%~65% COD reduction, therefore reducing fluctuation of COD in drainage. This study innovatively employed the pollutant source tracing method to identify sources of COD in smelting wastewater, and then controlled the amount of pollutants at the source, providing certain reference values for smelting wastewater treatment.

Considering high complexity and high safety requirements in the smelting section of metallurgical industry, a lightweight 3D digital twin system architecture based on Unreal Engine 5 (UE5) engine and pixel stream push technology was proposed. Cross-platform low-delay visual monitoring of the whole process of smelting section was realized through key technologies such as multi-level model lightweight processing, multi-terminal deployment of distributed pixel stream and real-time data-driven model construction. The system integrated functions of production control, data cockpit, automatic inspection and equipment disassembly, reducing hardware costs by more than 40% and increasing production efficiency by more than 20%. It provided a general technical path for metallurgical industry intelligence.

Amorphous alloys, also known as metallic glasses, have more active sites and better chemical and catalytic activity than traditional crystalline counterparts due to their long-range disordered atomic arrangement structure. Therefore, they have broad prospects in energy storage and conversion applications such as hydrogen energy, solar energy, and secondary batteries. This paper systematically reviewed the latest research progress of amorphous alloys utilized as electrocatalysis catalysts of water, hydrogen storage materials, lithium-ion battery and lithium battery materials, aqueous zinc-ion battery materials, key materials for solar cells, and supercapacitors, etc. Emphasizing the excellent performance of amorphous alloys, it focused on the influence of amorphous atomic structure on energy storage and conversion characteristics, and summarized tuning strategies of amorphous alloy structure and performance. Finally, it provided an outlook on the challenges and development trends in this field.

By analyzing the cutting performance of low copper content recycled brass alloy prepared from scrap copper, influences of lead mass fraction, process parameters, and environmental conditions on the surface processing quality of the material were studied. Results revealed the following trends: as lead content increased, both surface machining cutting force and roughness values of the material initially decreased and subsequently increased. When lead content ranged from 1.5% to 2.5%, surface roughness values exhibited minimal variation, all achieving relatively ideal levels with an average Ra value of approximately 2.5 μm. Notably, when the lead content reached 2.5%, surface machining cutting force was at its lowest, measuring F=164.96 N. With lead content fixed at 2.5%, optimal cutting performance was achieved when lathe rotational speed (n) was set at 700 r/min and feed rate (f) at 0.15 μm/Z. The use of coolant cooling method significantly reduced cutting force on the surface of the material to F=139.37 N, while surface roughness decreased to R_a=2.024 μm. Compared with natural cooling, air cooling method improved surface roughness of the material during processing, reducing it from R_a=2.529 μm to R_a=2.216 μm. This study provided practical process guidance for the efficient and precise machining of extruded round bars with recycled brass, offering significant potential for applications in material development and mechanical manufacturing.