Fräsmaschine für Keramikteile
Zusammenfassung der Projektergebnisse
The multi-anvil press (MAP) is one of the most powerful high-pressure apparatus in geoscience together with diamond anvil cells. In this apparatus, a sample is stored in an MgO octahedral pressure medium, and a ceramic heater is also embedded in a pressure medium. A pressure medium is squeezed by anvils with ceramic gaskets for pressure sealing. Manufacturing of these ceramic parts are very difficult due to their odd shapes and high material hardness. The machining center (Fräsmachine or Bearbeitungsmachine in German) was introduced to manufacture these parts automatically with high reproducibility. The followings are items that have been manufactured by this machining center: 1) MgO octahedral pressure media with a hole on the face for a heater and a cutting for a thermocouple. 2) MgO octahedral pressure media with a large hole for a heater on the faces, and small holes for a thermocouple on the opposite edges. 3) Pyrophillite gaskes with a 45-degree slop at the top edge. All multi-anvil experiments in the Bayerisches Geoinstitut have been supported more or less by this apparatus for the last three years. This machine has been placed in the central workshop of University of Bayreuth, so that other research groups also used it for their researches. The followings are research achievements by the Bayerisches Geoinstitut for which the machining center was used. 1) A pressure exceeding 65 GPa was generated by a multi-anvil press with carbide anvils for the first time in the world. A simultaneous generation of pressure of 45 GPa and temperature of 2000 K was also achieved. 2) Si grain-boundary diffusion coefficients were measured as a function of pressure, temperature and water content. This study suggests that transition of mechanism from diffusion to dislocation creep should occur in the uppermost mantle. 3) Single crystals of wadsleyite and ringwoodite were synthesized without flux. 4) Creep strength of ringwoodite was measured under its stability conditions. 5) In the dislocation creep of wadsleyite, partial dislocations are found to form, which implies wadsleyite strength should be low. 6) Temperature and pressure dependence of dislocation mobility of olivine in [100](010) and [001](010) slip systems was determined.
Projektbezogene Publikationen (Auswahl)
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(2015), Synthesis of large wadsleyite single crystals by solid-state recrystallization, Amer. Mineral., 100, 2336-2339
T. Kawazoe, J. Buchen, and H. Marquardt
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(2015): Dislocation microstructures in simple-shear-deformed wadsleyite at transition-zone conditions: Weak-beam dark-field TEM characterization of dislocations on the (010) plane. Amer Mineral 100, 2749
Miyajima, N.; Kawazoe, T.
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(2015): Synthesis of large wadsleyite single crystals by solid-state recrystallization, Amer Mineral 100, 2336-2339
Kawazoe, T.; Buchen, J.; Marquardt, H.
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(2016): Creep strength of ringwoodite measured at pressure-temperature conditions of the lower part of the mantle transition zone using a deformation-DIA apparatus. Earth Planet Sci Lett. 454, 10-19
Kawazoe, T.; Nishihara, Y.; Ohuchi, T.; Miyajima, N.; Maruyama, G.; Higo, Y.; Funakoshi, K.; Irifune, T.
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(2016): Generation of pressures over 40 GPa using Kawai-type multi-anvil press with tungsten carbide anvils. Review of Scientific Instruments 87, 024501
Ishii, T.; Shi, L.; Huang, R.; Tsujino, N.; Druzhbin, D.; Myhill, R.; Li, Y.; Wang, L.; Yamamoto, T.; Miyajima, N.; Kawazoe, T.; Nishiyama, N.; Higo, Y.; Tange, Y.; Katsura, T.
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(2016): New constraints on upper mantle creep mechanism inferred from silicon grain-boundary diffusion rates. Earth Planet Sci Lett. 433, 350-359
Fei, H.; Koizumi, S.; Sakamoto, N.; Hashiguchi, M.; Yurimoto, H.; Marquardt, K.; Miyajima, N.; Yamazaki, D.; Katsura, T.
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(2016): On the P-T fO2 stability of Fe4O5, Fe5O6 and Fe4O5-rich solid solutions. Contrib Mineral Petrol 171, 51
Myhill, R.; Ojwang, D.; Ziberna, L.; Frost, D.J.; Boffa Ballaran, T.; Miyajima, N.
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(2016): Temperature dependence of [100](010) and [001](010) dislocation mobility in natural olivine. Earth and Planet. Sci. Lett. 441, 81-90
Wang, L.; Blaha, S.; Pintér, Z.; Farla, R.; Kawazoe, T.; Miyajima, N.; Michibayashi, K.; Katsura, T.
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Experimental determination of melt interconnectivity and electrical conductivity in the upper mantle, Earth Planet Sci Lett. 463, 286–297, 2017
Laumonier, M., R. Farla, D. Frost, T. Katsura, K. Marquardt, A.-S. Bouvier & L. Baumgartner
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Identical activation volumes of dislocation mobility in the [100](010) and [001](010) slip systems in natural olivine, Geophys. Res. Lett.
Wang, L., S. Blaha, T. Kawazoe, N. Miyajima & T. Katsura
