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High-purity tellurium is a critical raw material for applications in solar energy, semiconductors, and other industries. Zone refining is the main method for preparing high-purity tellurium. Precise control over the zone refining temperature and the melting zone length is essential for improving impurity removal efficiency. Simulations demonstrated that optimizing the melting zone length and refining temperature significantly enhanced the stability of the melting zone compared to the unoptimized process. Under the conditions of three zone refining passes, a zone movement speed of 0.5 mm/min, and a hydrogen flow rate of 0.2 L/min, the impurity removal efficiency reached 95.9%, and the tellurium purity increased from 5N8 to 7N3. Achieving an optimal balance between efficiency and purity is crucial in the zone refining process to enhance production efficiency.

In this study, biodegradable and shape memory Zn-Ni-Ti-Sc alloys were fabricated by the mechanical alloying-powder injection molding method for temporary implant applications. Traditional Ni-Ti alloys are not biodegradable and need secondary surgery. Zinc, magnesium, and iron are biodegradable metals. Biodegradation of magnesium proceeds too quickly with H₂ evolution, iron is too slow, and zinc is in between. Shape memory alloys can undergo reversible plastic deformation and can return to their initially defined shape. The shape memory effect can be used in bone fracture applications as a compression bone screw, providing compression to the bone. Shape memory behavior provides stable compression of bone fractures. Powder injection molding is suitable for the production of complex parts. There is grain-coarsening and segregation in alloys produced by casting. Alloys with finer grain sizes and low segregation can be produced by using mechanical alloying and powder injection molding. The polymer binder consists of polyethylene, paraffin, and stearic acid. The feedstock consists of 4% binder and 55% alloy. After injection, the binder is removed and then the specimens are sintered. The mechanical, corrosion, and biodegradation properties were investigated. Also, alloys were studied according to computational materials science. Shape memory behavior was determined by compression tests, and 2% shape recovery was found.

Any metal alloy powder synthesized by solid-state hydrogen reduction of metal oxides should be chemically homogeneous for direct conversion into a versatile product. In this study, a 50-wt.% Fe₂O₃-NiO powder mixture was reduced using hydrogen for 45 min at 700°C and homogenized in argon at 1100°C. The absence of oxygen in the as-reduced and homogenized powders was confirmed via exhaust gas analysis and X-ray diffractometry. Three homogenization times, 5, 10, and 15 h, were tested in experimental trials based on simulation results. Energy-dispersive X-ray spectroscopy in a scanning electron microscope revealed few iron-rich sites in the sample homogenized for 5 h, a predominance of iron in the sample homogenized for 10 h, and a homogeneous composition after 15 h of homogenization. The 15-h-homogenized powder exhibited relatively extensive neck growth and minimal porosity, indicating suitability for direct use. Iron- and nickel-free impurities from the Fe₂O₃ feedstock were observed on and within powder particle boundaries. They were non-detrimental to the reduction and homogenization processes. These results demonstrate that solid-state reduction and homogenization at 1100°C for 15 h yield a microscopically homogeneous alloy powder, sinterable into a solid product. The findings are generalizable to other alloy systems and higher-order oxide mixtures.

Copper–tungsten (CuW) contacts face harsh and complex service environments such as high-temperature wear, arc ablation, and extrusion deformation during ultra-high-voltage power transmission. CuW composites are synthesized via in situ aluminothermic coupling with magnesiothermic reduction. The microstructure uniformity of CuW composites have been evaluated, and the three-dimensional morphology and particle size distribution of the extracted tungsten particles in the CuW composites were observed. The effects of the WO₃ size, additive NaCl, and the mixing method on the microstructure of CuW composites have been studied, and the results show that, with a decrease in WO₃ particle size, the average particle size of tungsten in CuW decreased from 1.22 μm to 0.92 μm, and the microstructural uniformity of CuW increased from 67.93% to 72.64%. The addition of NaCl was beneficial for the refinement of the tungsten particles and homogenization of the CuW microstructure. With the NaCl additions increased, the average size of tungsten particles in CuW decreased from 1.41 μm to 1.23 μm, and the microstructural uniformity increased from 68.78% to 71.68%. Ultrasonic premixing promoted mixing of CuO and WO₃ particles and dispersed tungsten particles in CuW, the uniformity of CuW microstructure increased from 67.98% to 73.55%.

This study introduced an enhanced method for the displacement reduction of selenium and tellurium from the leachate of copper anode slime utilizing nanoscale copper powder. The nanosized copper powder was synthesized through a facile method and characterized by its high surface energy and exceptional chemical reactivity. A series of displacement experiments was conducted to optimize the reaction parameters, achieving maximum recovery rates of 99.90% and 99.88% for selenium and tellurium, respectively, in 1 M H₂SO₄ medium after a 2-h reaction period. The results were substantiated through comprehensive analyses, including X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and infrared particle size distribution analysis, all of which confirmed the successful displacement and reduction of selenium and tellurium. This method offers a cost-effective and efficient strategy for the recovery of these valuable rare metals.

In order to achieve effective dephosphorization in the double slag converter steelmaking process, the effect of basicity on the break temperature and phase composition of slag from the double slag converter steelmaking process was studied in this work by using X-ray diffraction (XRD) and scanning electron microscope equipped with energy dispersive spectrometer (SEM-EDS). The results showed that the break temperature and activation energy of slag exhibited an increasing trend followed by a decrease with the increase of basicity, reaching its highest value at 1.7, indicating the highest flow resistance of the slag. During the cooling process from 1450 °C to 1390 °C, the mineralogical phase composition of steelmaking slag underwent significant transformation. When the temperatures were 1450 °C and 1390 °C, an increase in basicity from 1.3 to 1.7 resulted in sufficient growth and precipitation of a phosphorous -rich phase. This study could provide the theoretical and technical foundation for optimizing the double slag converter steelmaking process.

A conventional heat treatment may not be necessarily suitable for additive-manufactured maraging steel (18Ni300) owing to the heterogeneous microstructure developed during the process. The present study investigated the influence of two different solution treatment temperatures, 820°C (ST-820C: conventional) and 900°C (ST-900C: alternative), on the microstructure and mechanical properties of laser powder bed fusion (LPBF) processed 18Ni300. The investigation was conducted on specimens produced at two scan speeds (420 mm·s⁻¹ [S420] and 850 mm·s⁻¹ [S850]) with maximum relative density. The ST-820C resulted in partial homogenization owing to residual microsegregation, whereas ST-900C achieved complete homogenization and yielded a uniform lath martensitic structure. Although the S850 condition exhibited finer microstructures, the S420 samples showed marginally superior strength and ductility in the as-built condition, attributed to a lower retained austenite fraction. This contrasting difference decreased slightly after solution treatment because of an increase in martensitic block width and a decrease in retained austenite. Impact toughness was high in the as-built condition (56 J) and decreased after aging (STA-820C: 16 J; STA-900C: 12 J) because of brittle intermetallic precipitates. These findings demonstrate the essential need for heat treatment optimization in LPBF AM maraging steel to obtain a homogeneous microstructure and superior mechanical properties.

Cerium conversion coatings (Ce CCs) modified by copper and manganese cations were applied to a galvanized steel substrate. In order to investigate the effect of copper and manganese cations on the microstructure and composition of Ce CCs, copper and manganese sulfates were added to the Ce CC bath. The microstructure and composition of the specimens were analyzed by field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Electrochemical impedance spectroscopy (EIS) was used to investigate the corrosion behavior of the coatings. The EIS data indicate that the corrosion resistance of the coatings is enhanced in the presence of Cu and Mn additives. AFM results showed a significant decrease in surface roughness from 75 nm in unmodified Ce CC to 20 nm (Ce CC + Mn) and 13 nm (Ce CC + Cu), which confirms the surface uniformity improvement. XPS analysis revealed an increase in Ce–O content from 10% (Ce CC) to 27% (Ce CC + Cu) and 20% (Ce CC + Mn). This improvement is related to more stable oxide formation. These findings highlight that Cu and Mn increased the corrosion resistance of galvanized steel by improving Ce CCs as an environmentally friendly treatment method.

The present study demonstrates a simple hydrothermal technique for the fabrication of Cu-doped BaCoO₃ nanostructure electrode material. The developed materials, after evaluation of physical characterizations, showed excellent surface area, purity, and morphology. However, electrochemical characterizations of materials took place within 3.0 M KOH. According to experimental results, Cu-doped BaCoO₃ material demonstrates an impressive specific capacitance of 1944 F/g over a current density of 1 A/g, and it also shows better cycling efficiency and rate capability. According to chronoamperometry analyses, the Cu-doped BaCoO₃ exhibits mechanical stability of 50 h along with excellent mechanical stability (50 h). The greater surface area, small crystallite size, and the synergistic impact within Cu-doped BaCoO₃ nanostructure are all linked to excellent electrochemical response. Our findings imply that the synthesized electrode has shown superior electrochemical energy storage capability and has the potential to address other energy storage-related problems.