JpGU-AGU Joint Meeting 2017

講演情報

[EE]Eveningポスター発表

セッション記号 S (固体地球科学) » S-CG 固体地球科学複合領域・一般

[S-CG62] [EE] 変動帯ダイナミクス

2017年5月23日(火) 17:15 〜 18:30 ポスター会場 (国際展示場 7ホール)

[SCG62-P25] かんらん石細粒多結晶体の焼結

*坪川 祐美子1石川 正弘1 (1.横浜国立大学大学院 環境情報)

キーワード:焼結、かんらん石、多結晶体

The rheological properties of Earth’s interior have been determined by laboratory experiments of polycrystalline samples of rock-forming minerals. In these deformation experiments, fine-grained specimens are often required for deformation in diffusion creep regime at laboratory strain rates (e.g. Karato, 2010). In this study, we successfully fabricated olivine nano-sized powder from naturally occurring olivine single crystal (peridot:Mg1.76~1.84Fe0.16~0.24SiO4). In order to investigate a method for preparing fine-grained and highly dense nanocrystalline olivine, the sintering behavior of olivine powder was studied. Olivine powder were pressed into cylindrical shape and sintered under argon flow at temperatures ranging from 1130-1350 ℃ for 2-6 hours. After the sintering, sample surfaces were polished and thermally etched to expose grain boundaries. Grain size and porosity were determined from the microstructure of scanning electron microscope. Olivine grains in sintered samples are polygonal and isotropic shape, and show a homogeneous structure. The average grain size increased with increasing sintering time and sintering temperature, and a significant grain growth was found for the sample sintered at 1350 ℃. At temperatures of 1300 ℃, we could obtain dense polycrystalline olivine with an average grain size of < 2 μm.