| Project/Area Number |
63460201
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
TANAKA Koichi Nagaoka University of Technology, Faculty Technol., Professor., 工学部, 教授 (90143817)
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| Co-Investigator(Kenkyū-buntansha) |
KOGUCHI Hideo Nagaoka University of Technology, Technol., Associate Professor., 工学部, 助教授 (90143693)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1988: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | elastic / plastic hardness / dislocation / ceramics / nanoindentation / carbon film / ferrite / SEM topography / scanning tunneling microscopy / 圧痕 / 磁気記録媒体 / 薄膜 / プリズマティックル-プ / 超微小硬度計 / 転位ループ |
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| Research Abstract |
1. A dislocation model for elastic/plastic indentation hardness of brittle materials.
A new model for analyzing indentation plasticity is proposed, and is discussed in relation to the plasticity in ceramics. The model is based on the punching of prismatic dislocation loops to accommodate the volume of plastic penetration at the indentation. The theory predicts that the hardness/Young's modulus ratio is almost constant irrespective of the yield strength. The predicted profiles in Si_3N_4 and ZrO_2 ceramics were closely coincident with the indentation profiles observed by a topographic scanning electron microscope (SEM).
2. Construction of a nanoindentation tester
A nanoindentation tester was constructed. The applied load is measured by an electronic microbalance with a 0.5muN resolution and the penetration depth is obtained by a fiber optical lever with a lmm resolution. The nanoindentation behaviors were examined using the instrument for three brittle materials, glass, overcoated graphite and lap-finished MnZn ferrite. The Young's modulus of an optical glass obtained from the indentation elastic carve was coincident with the calculated value by using a finite element method. The characterization was successfully made for the overcoated graphite films with 30nm thickness on a thin-film magnetic disk, and for the severely deformed zone at the surface of the machinefinished ferrites.
3. Measurement of surface profiles in the nanometer order of roughness
The principle of SEM topography was considered. The SEM topography was used for the measurement of the surface profile of the nanomater order on a thin-film magnetic disk and the results was discussed in comparison with that obtained by scanning tunneling microscopy.
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