著者
Hao Yu Shigeharu Ukai Shigenari Hayashi Naoko Oono
出版者
The Japan Institute of Metals and Materials
雑誌
MATERIALS TRANSACTIONS (ISSN:13459678)
巻号頁・発行日
vol.59, no.4, pp.563-567, 2018-03-25 (Released:2018-03-25)
参考文献数
23
被引用文献数
4 6

Alumina-forming oxide dispersion strengthened (ODS) superalloys are favorable oxidation-resistant materials for extremely high temperature applications. In order to develop the advanced Co-based superalloys with high strength and superior oxidation resistance at elevated temperature of 1000℃, a new series of Co-Cr-Al ODS superalloys were designed and fabricated by mechanical alloying (MA) and spark plasma sintering (SPS), and then followed by hot rolling and annealing at 1200℃. In this work, the oxidation behavior of Co-10Al (mass%) ODS superalloys with/without 20Cr was investigated at 1000℃ in air to understand the effect of Cr on oxidation resistance. The results indicate that the addition of Cr improves the oxidation resistance significantly through optimizing the oxide scales from the multilevel scales with an external CoO/CoAl2O4 and an internal Al2O3 to a single layer of Al2O3. The alumina-forming Co-20Cr-10Al (mass%) ODS superalloys are expected to be applicable at 1000℃.
著者
Yuchen Liu Sosuke Kondo Hao Yu Kiyohiro Yabuuchi Ryuta Kasada
出版者
The Japan Institute of Metals and Materials
雑誌
MATERIALS TRANSACTIONS (ISSN:13459678)
巻号頁・発行日
vol.61, no.5, pp.955-962, 2020-05-01 (Released:2020-04-25)
参考文献数
32
被引用文献数
5

Oxide Dispersion Strengthening copper (ODS-Cu) alloy has high strength, high thermal conductivity and superior irradiation resistance which are needed for fusion reactor divertor components. In this study, specimen size dependence of the yield stress in Cu and ODS-Cu which were made by mechanical alloying and hot pressing was investigated by micro-pillar compression test. The distributions of yield stress values were different between the sizes, 1, 3 and 5 µm cubic micro-pillars, which can be explained by the inhomogeneous spatial distributions of both the crystallographic grain in matrix and oxide-particles.