Microstructure and High-Temperature Performance of High K-Doped Tungsten Fibers Used as Reinforcement of Tungsten Matrix

Tungsten (W) fiber-reinforced tungsten (Wf/W) composite with ultra-high strength and high-temperature resistance is considered an attractive candidate material for plasma-facing materials (PFM) in future fusion reactors. The main component of Wf/W composite is tungsten wire, which is obtained through powder metallurgy and the drawing process. In this paper, high potassium (K)-doped tungsten wires with 98 ppm of K and 61 ppm of impurities are prepared using traditional and optimized processing technologies, respectively, and a comparative study with conventional K-doped tungsten wires with 83 ppm of K and 80 ppm of impurities is conducted. The high-temperature mechanical properties as well as the microstructure’s evolution of the prepared tungsten wires are investigated. The results show that the high-temperature performance of K-doped tungsten wires is improved by increasing the K content and by simultaneously reducing the impurities. By adopting small compression deformation and low-temperature processing technology, the high-temperature performance of high K-doped tungsten wires can be further improved. A microstructure analysis indicates that the excellent high-temperature performance is attributed to a combination of the small K bubble size, high K bubble number density, and long K bubble string, which are produced through optimization of the processing technology. A study on the processing technology and the performance of tungsten wires with a high K content and a high purity can provide important information regarding Wf/W composites.

Spinel LiMn2O4 Nanorods via Template–Engaged Method and as Cathode Materials for Li-Ion Batteries

Spinel LiMn2O4 nanorods were prepared by a hydrothermal method followed by solid-state lithiation. The produce β-MnO2 nanowire as template, and LiOH·H2O was used as lithium source. The spinel LiMn2O4 nanorods samples were characterized by SEM, XRD, (HR)TEM, and galvanostatic charge/discharge profile measurement. Compared with the LiMn2O4 nanoparticles, the LiMn2O4 nanorods showed superior cycling stability, better rate capability, good high temperature performance, and delivered a discharge capacity of 122 mAh/g (at 1 C, 100 cycles).

Influence of Relative Molecular Mass of SBS on Low-Temperature Performance of Modified Asphalt

Styrene Butadiene Styrene (SBS) is widely used in pavements because it significantly improves the performance of the modified asphalt. The dosage of SBS has an important effect on the low-temperature performance of the modified asphalt. The difference in relative molecular weight influences the magnitude of the change in low-temperature performance. In this paper, low temperature bending beams rheology test of five different relative molecular weight SBS modified asphalt is conducted at -12°C, -18°C and -24°C to evaluate the low-temperature properties of modified asphalt. Then, the experimental results are analysed. The results show that there is a certain correlation between the relative molecular mass of SBS and the low-temperature performance of modified asphalt. The creep stiffness and creep rate of the modified asphalt are influenced by the relative molecular mass of SBS and temperature. As the relative molecular mass increases, the low-temperature performance of the modified asphalt first rises and then decreases.

Research on the Impact of Recycled Asphalt Mixture on Road Performance Based on New Thermal Recycling

Different binder content to RAP Regeneration SBS modified asphalt mixture for road performance to SBS modified asphalt (I-D type) as an index, determine the optimum dose of new heat regenerating agent and different RAP regeneration, and prepared different recycled asphalt, which have differences in RAP content. The performance of recycled asphalt mixture with different RAP content was evaluated by freeze-thaw splitting test. Rut test and Low temperature trabecular bending test. The correlation between RAP content and pavement performance was analyzed by grey system correlation analysis method. According to the experimental verification results, it can be known that increasing the content of RAP material can improve the high-temperature performance of reclaimed asphalt, but will result in a qualitative decrease in low-temperature performance and water temperature, but the above-mentioned performance can reach the required level, Shows that new heat regenerators play a role in the road performance of RAP materials, and for the RAP material utilization ratio of more than 50%, as for the gray correlation analysis, it can be found that there is a close correlation between the low-temperature performance of recycled asphalt mixture and the content of RAP material. The low temperature cracking resistance of asphalt mixtures will change significantly due to the slight changes in RAP materials.