Presentations -

Fabrication of diamond particle dispersed metal matrix composites by spark plasma sintering (SPS) for high thermal conductive materials Invited International conference

Mikio Ito

The 13th International Conference on Nanostructures, Nanomaterials and Nanoengineering, ICNNN 2024  2024.11  Science and Engineering Institute

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Diamond particle dispersed metal matrix composites (MMCs) were fabricated by spark plasma sintering (SPS) in order to provide high performance thermal management materials. In the case of Al matrix composites, the samples were consolidated in continuous solid-liquid co-existent state by SPS process from the mixture of diamond powders, pure Al powders and Al-5mass%Si alloy powders. the microstructures and thermal conductivities of the composites obtained were examined. These composites were all well densified by heating at a temperature range between 798K and 876K for 1.56ks during SPS process. No reaction at the interface between the diamond particle and the Al matrix was observed by scanning electron microscopy for the composites fabricated under the sintering condition employed in this study. The relative packing density values of the diamond–Al composites obtained were 99% or higher in a volume fraction range of diamond between 45vol.% and 50cvol.%. Thermal conductivity of the diamond-Al composite containing 50vol.% diamond reached 552 W/mK, approximately 95% of the theoretical thermal conductivity estimated by using Maxwell-Euchen’s equation.

Densification of thermoelectric β-FeSi2 by directly applied current sintering process Invited International conference

Mikio Ito

Powder Metallurgy World Congress & Exhibition, World PM 2024  2024.10  Japan Powder Metallurgy Association, Japan Society of Powder and Powder Metallurgy

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The thermoelectric β-FeSi2 powder, was sintered by modified pulsed electric current sintering (PECS) using graphite punches and an insulating quartz glass die. The sample powders were heated by directly applied current and their sintering behaviors were compared to those of the samples sintered by the conventional PECS (using graphite punches and a graphite die). During the heating in the quartz die, the transformation from mechanically alloyed metallic Fe-Si powder to the semiconductive β-FeSi2 phase occurred at a temperature lower than when sintered by the conventional PECS. After the transformation, the shrinkage of compact became larger than that of the sample sintered by the conventional method. The sample sintered by this modified PECS process showed the thermal conductivity smaller than the sample prepared in the conventional process because of its finer microstructure due to the rapid densification, resulting in lager figure of merit.

Thermoelectric properties of β-FeSi2 prepared by directly applied pulsed electric current sintering Invited International conference

Mikio Ito

Asia Pacific Society for Materials Research 2021 Annual Meeting (APSMR 2021 Annual Meeting)  2021.8  APSMR 2021 Annual Meeting Committee

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As an electrically conductive powder, thermoelectric β-FeSi2 powder, was sintered by modified pulsed electric current sintering (PECS) using graphite punches and an insulating quartz glass die. These powders were heated by directly applied current and their sintering behaviors were compared to those of the samples sintered by the conventional PECS (using graphite punches and a garphite die). During the heating in the quartz die, the transformation from mechanically alloyed metallic Fe-Si powder to the semiconductive β-FeSi2 phase occurred at a temperature lower than when sintered by the conventional PECS. After the transformation, the shrinkage of compact became larger and the density of a sintered body was higher as compared to those of the sample sintered by the conventional method. The sample sintered by this modified PECS process showed the thermal conductivity smaller than the sample prepared in the conventional PECS process because of its finer microstructure due to the rapid densification. On the other hand, the electrical resistivity and the Seebeck coefficient of this sample were slightly reduced and enhanced, respectively, resulting in the significantly lager figure of merit as compared to the conventionally sintered sample.

Rapid and energy-saving densification of metallic and semiconducting powders by using directly applied current sintering International conference

Mikio Ito

The 4th International Conference on Functional Materials and Metallurgy (ICFMM 2019) 

Rapid densification of electrically conductive powders by Joule heating in directly applied current sintering International conference

Mikio Ito

The 8th International Conference on Nanostructures, Nanomaterials and Nanoengineering (ICNNN 2019) 

Preparation of heterogeneous β-FeSi2/Si composites synthesized by eutectoid decomposition and their thermoelectric properties International conference

Mikio Ito

International Conference on Material Science and Engineering. (Materials Science- 2019) 

Rapid and energy-saving sintering of electrically conductive powders by directly applied current heating International conference

Mikio Ito

2019 4th International Conference on Smart Materials Applications (ICSMA 2019) 

Sintering of electrically conductive powders by directly applied current heating International conference

Mikio Ito

The International Conference on Nanostructures, Nanomaterials and Nanoengineering (ICNNN 2018) 

Effects of P doping on the thermoelectric performance of heterogeneous β-FeSi2/Si composites International conference

Mikio Ito, Fafah Liana, Masatoshi Takeda

The 9th International Conference on PROCESSIMG & MANUFACTURING OF ADVANCED MATERIALS (THERMEC 2018) 

Thermoelectric performance of heterogeneous β-FeSi2/Si composites synthesized by eutectoid decomposition International conference

Mikio Ito

The 2018 5th Global Conference on Polymer and Composite Materials (PCM 2018) 

Synthesis of thermoelectric materials by directly applied current sintering process International conference

Mikio Ito

The 8th International Conference on Key Engineering Materials (ICKEM 2018) 

Synthesis of thermoelectric β-FeSi2 via directly applied current sintering International conference

Mikio Ito

The 6th Global Conference on Materials Science and Engineering (CMSE 2017) 

Densification behavior and thermoelectric properties of β-FeSi2 synthesized by directly applied current sintering International conference

Mikio Ito

International Conference on Frontiers in Materials Processing Applications, Research and Technology, FiMPART’2017 

Synthesis of β-FeSi2 by directly applied current sintering and its thermoelectric properties International conference

Mikio Ito and Kenta Kawahara

The 8th International Conference on PROCESSIMG & MANUFACTURING OF ADVANCED MATERIALS (THERMEC 2016) 

Thermal conductivity of cubic boron nitride particle dispersed Al matrix composites fabricated by SPS International conference

Kiyoshi Mizuuchi, Kanryu Inoue, Yasuyuki Agari, Motohiro Tanaka, Takashi Takeuchi, Jun-ichi Tani, Masakazu Kawahara, Yukio Makino, Mikio Ito

The 8th International Conference on PROCESSIMG & MANUFACTURING OF ADVANCED MATERIALS (THERMEC 2016) 

SPS法により作製した傾斜機能材料の状態分析－Al2O3/TiとZrO2(3Y)/SUS410Lの比較－

巻野勇喜雄，水内　潔，井藤幹夫

第20回通電焼結研究会 

Densification Behaviors of Electrically Conductive Powders Sintered by Directly Applied Current Heating Process International conference

Mikio Ito

The 11th Pacific Rim Conference of Ceramic Societies, PACRIM 11 

Thermal Properties of cBN Particle Dispersed Al Matrix Composites Fabricated by SPS International conference

Kiyoshi Mizuuchi, Kanryu Inoue, Yasuyuki Agari, Masami Sugioka, Motohiro Tanaka, Tahashi Takeuchi, Jun-ichi Tani, Masakazu Kawahara, Yukio Makino and Mikio Ito

Japan-Russia Workshop on Advanced Materials Synthesis Process and Nanostructure 

Characterization of the interfaces in diamond/metal composites International conference

Yukio Makino, Kiyoshi Mizuuchi, Yasuyuki Agari and Mikio Ito

Japan-Russia Workshop on Advanced Materials Synthesis Process and Nanostructure 

Synthesis of thermoelectric Mg2Si polycrystals by directly applied current heating International conference

Mikio Ito and Kenta Kawahara

Japan-Russia Workshop on Advanced Materials Synthesis Process and Nanostructure 

熱電変換材料のSPS合成

井藤幹夫

京都市産業技術研究所・講演会 

Effect of bimodal distribution of diamond particle size on thermal conductivity of Al/diamond composite fabricated by SPS International conference

Kiyoshi Mizuuchi, Kanryu Inoue, Yasuyuki Agari, Masami Sugioka, Motohiro Tanaka, Tahashi Takeuchi, Jun-ichi Tani, Masakazu Kawahara, Yukio Makino and Mikio Ito

The 7th International Conference on PROCESSIMG & MANUFACTURING OF ADVANCED MATERIALS (THERMEC 2013) 

Thermoelectric Properties and Densification Behavior of SrTiO3/TiB2 Composites International conference

Mikio Ito and Naoki Hasegawa

The 7th International Conference on PROCESSIMG & MANUFACTURING OF ADVANCED MATERIALS (THERMEC 2013) 

Thermal Properties of Al/Diamond Composites Fabricated in Continuous Solid-Liquid co-Existent State by SPS International conference

K. Mizuuchi, K. Inoue, Y. Agari, Y. Morisada, M. Sugioka, M. Tanaka, T. Takeuchi, J. Tani, M. Kawahara, Y. Makino and Mikio Ito

The 7th International Conference on PROCESSIMG & MANUFACTURING OF ADVANCED MATERIALS (THERMEC 2013) 

SPSプロセスによるn型SrTiO3系熱電変換酸化物の合成

井藤幹夫

第4回パルス通電懇話会