Si nanoparticles are considered promising as anode materials for next-generation high-capacity lithium-ion batteries. Plasma flash evaporation using RF plasma spraying enables continuous production of Si nanoparticles and is expected to be a high-throughput mass production technology. However, there is concern that the mixing of coarse particles due to fluctuations in processing will worsen the cycle characteristics of the battery. In this report, in-situ classification was performed by installing an axial cyclone directly under the torch for the purpose of removing as-received powder size coarse particles. In an experiment, it was confirmed that a swirling flow was generated under normal manufacturing conditions without additional gas for classification. In plasma treatment using Si as-received powder with an average size of 20 μm, coarse particles larger than 10 μm were removed, and only nanoparticles of 40-50 nm were collected in the filter. In addition, the particle size distribution of the generated particles was improved. From the consideration using CFD, it was speculated that the installation of the cyclone contributed to the decrease of fluctuations in the particle processing hysteresis.

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In recent years, three-dimensional inspection of internal defects using X-ray CT method has become popular. This technology is characterized by its ability to nondestructively acquire three-dimensional images, enabling three-dimensional observation of the internal structure of materials. Quality control of thermal spray coatings is performed by measuring the coating hardness and observing the coating structure so on. There are several methods for measuring porosity in coating, but the measurement conditions affect the results in the method with binarized image processing. Evaluation of microdefects in thermal spray coatings by X-ray CT would be very useful for quality control, but there are few studies on this subject.
In this study, alumina coatings deposited by plasma spraying were evaluated using an X-ray CT system at BL20B2 in SPring-8 synchrotron radiation facility. As a result, clear reconstructed images were obtained, and small pore-like structures were observed. The images of the cortex showed uneven black-and-white contrast. This was thought to be due to pores and unjoined areas between the layers in coating. The linear absorption coefficient map showed locally elevated areas, possibly due to unmelted particles in the coating. X-ray CT at a synchrotron radiation facility may be able to evaluate microdefects in thermal sprayed coatings.

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The purpose of this study is to establish product structures and their manufacturing methods that improve the adhesion between quartz glass substrates, which have an extremely small coefficient of thermal expansion, and ceramic sprayed coatings with thickness over 300 μm. This study was investigated using the following two methods. First, a material for a base layer that has high adhesion to the quartz glass was selected, and we found that a dense Yttria (Y₂O₃) sprayed coating effectively functions as a buffer layer. Second, the strength of blasted quartz glass substrates decreases by the influence of a fracture layer, but we founded that the fracture layer could be repaired by applying appropriate heat treatment to blasted substrates. It was confirmed that such a treatment further improves the adhesion between the Y₂O₃ coating and the quartz glass. The product structures established in this study allow the ceramic sprayed coatings to be removed without damaging the substrates by applying a self-supported film manufacturing method. Therefore, the quartz glass substrate can be reused without being discarded, and by repeatedly recoating the protective film, it will be possible to realize circular manufacturing, which is a circular business related to the 3Rs (Reduce, Reuse, and Recycle)

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In this study, to develop a high rate ceramic coating process for plastic articles, TiO₂ film deposition on transparent acrylic resin was conducted by SPPS, which has been known as a practical fine particle production process. Consequently, in both cases of Ar and Air working gases, film strength was increased though degree of crystallinity and photo-catalytic property of the film were decreased with elongating spray distance. However, as-deposit TiO₂ films deposited on the acrylic resin substrate had enough photo-catalytic property and strength to be used practically in any cases. This result suggested that amorphous fine particles which were created in the plasma jet still had high bonding strength after reaching the substrate. From these results, this technique was proved to have high potential for ceramic film deposition for plastic articles.

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Reactive Plasma Spraying (RPS) presents a promising approach for in-situ formation of challenging ceramic coatings not easily achievable with conventional thermal spraying methods. It categorizes into solid-solid RPS and solid-gas RPS based on reactant states. This paper focuses on the solid-gas RPS process, specifically the plasma nitriding of Al particles for aluminum nitride (AlN) coating fabrication. Various factors, such as particle nitriding mechanism, in-flight time, particle size, splat morphology, N₂ plasma gas, and feeding rate, are discussed to provide a comprehensive overview of the RPS process.

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This paper presents a novel application of atmospheric UV treatment for electroless plating on various insulating resins. It highlights the significance of surface treatment techniques, classified into dry and wet methods, in enhancing the performance, durability, and safety of materials such as metals and semiconductors. Specifically, the study focuses on electroless plating, a wet process, and introduces UV modification as an eco-friendly alternative to conventional methods. The research demonstrates that UV treatment maintains the resin′s inherent properties like smoothness, transparency, and electrical characteristics while improving adhesion. The technique is applicable to a diverse range of resins, including ABS, epoxy, PI, LCP, ABF, polyester, COP, and PA, enabling the formation of complex metal patterns without using resists. In conclusion, the technology′s adaptability to large-scale and roll-to-roll processing opens up prospects for its application in various industries, including electronics, medical electrodes, and heating materials.

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