Sintering and deformation properties of peridotite in an electrical field

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01190
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 17040:Solid earth sciences-related
• Research Institution: Shizuoka University
• Principal Investigator: Tasaka Miki 静岡大学, 理学部, 准教授 (80772243)
• Co-Investigator(Kenkyū-buntansha): 吉田 英弘 東京大学, 大学院工学系研究科(工学部), 教授 (80313021)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: かんらん岩 / 変形 / 電場 / 拡散

Outline of Final Research Achievements

A new technique called “flash sintering” has been proposed in the field of materials science. When tensile deformation experiments conducted on a dense oxide body in an electrical field have shown that plastic deformation can be enhanced at lower temperatures with lower stresses, as compared with conventional deformation experiments. Fluctuations in the magnetic and electrical fields derived from outside Earth, such as solar activity, induce an electrical field inside Earth. Although electrical fields inside Earth may affect the deformation behavior of rocks, no experimental studies have been conducted on geomaterials to assess this effect. Therefore, based on these recent findings in materials science, we conducted sintering and deformation experiments to examine the effects of an electrical field on high-temperature mass transport.

Free Research Field

実験岩石学

Academic Significance and Societal Importance of the Research Achievements

焼結実験中に電場を加えると密度が増加し電場を加えない場合より短時間で緻密化が進むことが分かった。変形実験中に電場を加えると、電場を加えない場合に比べて同じ荷重で１桁程度ひずみ速度が速くなることが分かった。これは電場下で空孔濃度が変化し物質拡散が加速したためと考える。太陽活動などの地球外部起源の磁場と電場の変動により、地球内部に電場が誘導される。地球科学分野の実験岩石学的な研究において、岩石の粘性率に関する水やメルトの効果は多くの先行研究があが「電場の効果」は本研究で初めて実験的に示された。