脱炭素、安全・安心社会の実現に向けて、産業機器、エネルギー機器、モビリティをはじめとした様々な分野の省エネ化、高安全化に資する最先端材料やモノづくりのプロセスに関する研究開発
（マテリアルズインフォマティクスを活用した金属・樹脂・複合材料等の最先端材料技術に関する研究開発および省エネ化、社会インフラプロダクトを支えるモノづくり工程のデジタル化、CO2排出削減に向けた材料プロセス技術、検査・計測機器の高度化技術）
金属・樹脂・複合材料等の最先端材料、高信頼化技術、プロセス技術、マテリアルズインフォマティクス（材料シミュレーション、プロセスシミュレーション）、モノづくりDX化技術（材料プロセスナレッジとデジタル技術の両方を用いた開発）、光学設計技術
Publishing Academic Papers:
Satoshi Ishii, Hitomi Takahashi and Yoshie Sakai
Smart Materials and Structures, Volume 33, Number 12
Viscoelastic properties of electro-rheological fluids containing ion-conductive polyurethane particles under electric field
Abstract: A non-hydrous electro-rheological fluid (ERF) containing polyurethane (PU) particles with electrolytes and automotive dampers utilizing it have been developed. In this study, we investigated the influence of electrolytes and particle properties on ER effect (yield stress) leading to improving the ER effect of non-hydrous ERFs. As a result, yield stress was increased by the inclusion of electrolytes to PU particles and decreased by increasing the glass transition point (Tg) of PU. The inclusion of electrolyte in particles doubled the yield stress of ERF at 5 kV mm-1. The change in Tg of PU particles from -26.3 °C to -15.3 °C resulted in a decrease in yield stress by 0.7 times at 5 kV mm-1. According to a theoretical model for calculating the ER effect and experimental data, the ionic conductivity associated with the electrolyte addition and the Tg change contributed to the dielectric constant of the PU particles, which affected the ER effect. This result provides important knowledge for deriving material compositions that can further improve the ER effect.
Hitomi Takahashi and Satoyuki Nomura
Tribology Online, Vol. 19, No. 3 (2024) /208
Effects of Hydrogen Peroxide on Chemical Mechanical Polishing of Copper Surface:
Exploration of Reaction Pathways with Molecular Dynamics Simulation and Activation
Energies Calculation
Abstract:The mechanisms of chemical mechanical polishing (CMP) of copper (Cu) surface using a slurry containing hydrogen peroxide (H2O2) and silica abrasive grains were theoretically investigated. First, molecular dynamics (MD) simulations using ReaxFF were used to analyze reactions that remove Cu atoms from the Cu(111) surface. At the Cu/H2O2 interface, Cu atoms were oxidized by forming Cu-O bonds with O atoms derived from H2O2 or H2O. The behavior of the oxidized Cu atoms depended on the surrounding environment. Following two types of reaction pathways for the removal of oxidized Cu atoms were found. In the first pathway, neighboring Cu atoms were oxidized. In the second pathway, the atomic arrangement around the oxidized Cu atoms was disordered caused by surface vacancies. In relation to the first reaction pathway, activation energies were calculated to study the effects of the oxidation of Cu atoms on the Cu removal reactions. The results showed that the lowest activation energy was obtained when the structure in which neighboring Cu atoms were most oxidized, which supported the results of the MD simulations. The findings of this study indicate that
the oxidation degree of adjacent Cu atoms and the atomic arrangement of the Cu surface affect the Cu removal reactions.
Hayate Saito , Masahiro Ito, Katsumi Mabuchi
CORROSION (2023) 79 (11): 1267-1276.
Empirical Model for Predicting Corrosion Under Insulation Considering the Effects of Temperature, Salinity, and Water Content
Abstract: Corrosion under insulation (CUI) is one of the increasing issues in industries such as oil refineries and petrochemical plants. For preventing accident and reducing the inspection load caused by CUI, the prediction model for CUI has attracted increasing attention. In this study, to construct a prediction model for the corrosion rate of CUI (CUI rate), the effects of water content in the insulation material, salinity, and temperature on the CUI rate were evaluated with a corrosion test simulating a CUI environment. Analysis of the atmospheric corrosion monitoring sensor current showed that the CUI rate increased as the water content increased, promoting the formation of the water-thin film at the interface of insulation and carbon steel. Maxima of the CUI rate were observed for salinity and temperature. Salinity increased the electrical conductivity of the water-thin film and promoted the corrosion reaction, and over a certain salinity, the water-thin film became thicker and the CUI rate decreased due to the rate-determining step in oxygen diffusion. Over a certain temperature, the CUI rate decreased due to the evaporation of the water-thin film and a decrease in dissolved oxygen. We constructed the prediction model for the CUI rate with a coefficient of determination of 0.87 by multiple regression analysis using the obtained test data.
Masahiro Ito , Kenya Ohashi, Kazumi Fujii, Kyoko Hombo, Katsumasa Miyazaki, Azusa Ooi, Eiji Tada, Atsushi Nishikata
ISIJ International, Vol. 62 (2022), No. 3, pp. 568-576
Identification of Chromium-Depleted Area around Chromium Nitride Precipitates in Heat-affected Zone of Lean-Duplex Stainless Steel and In-situ Observation of Preferential Dissolution by EC-AFM
Abstract: A Gleeble thermo-mechanical simulator was used to simulate the welds of duplex stainless steel S32101. A micro-precipitate of chromium-nitride and its surroundings in the simulated welds was analyzed in detail by SEM/AES and EC-AFM. The AES analysis revealed that a chromium-depleted area is present in the γ phase near the chromium-nitrides precipitated at the α/γ grain boundary. The EC-AFM observation revealed that the duplex stainless steel preferentially dissolves from the chromium-depleted area.
2023年度 溶接接合工学振興会 金澤賞
「高精度動作センシングによる溶接技能 のデジタル化と溶接士技能を搭載した 溶接自動化技術の開発」
2023年度 エレクトロニクス実装学会 マイスター賞
「プリント配線基板表面処理技術および低環境負荷めっき技術の開発」
2023年度 第37回春季講演大会 ポスターアワード賞
「動的共有結合樹脂を適用した際成形可能なFRP」
2022 年度溶接学会 ベストオーサー賞
「最新の溶接技能伝承 高精度動作センシングによる溶接技能デジタル化と溶接士技能を搭載した溶接自動化」
2022年度 第31回ポリマー材料フォーラム 広報委員会パブリシティ賞
「公開データから探索したバイオ由来ポリ乳酸樹脂用添加剤の効果実証」
2021年度 日本溶接協会 技術賞
「自動車燃料系部品へのレーザ溶接溶込み深さ 全数検査技術の適用」
2020年度 日本機械学会 材料力学部門 業績賞
「電子デバイスを高信頼化させる原子レベル材料設計に関する先駆的研究」
公開データのAI分析で強度と生分解性を両立させるバイオ由来樹脂用添加剤を探索し実証
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