| Project/Area Number |
12450281
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Toyohashi University of Technology |
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Principal Investigator |
UMEMOTO Minoru Toyohashi University of Technology, Faculty of Engineering, Professor, 工学部, 教授 (90111921)
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| Co-Investigator(Kenkyū-buntansha) |
TSUCHIYA Koichi Toyohashi University of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (50236907)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥14,300,000 (Direct Cost: ¥14,300,000)
Fiscal Year 2001: ¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 2000: ¥9,700,000 (Direct Cost: ¥9,700,000)
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| Keywords | steel / cementite / mechanical alloying / sintering / strength / allying / mechanical properties / physical properties |
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| Research Abstract |
Cementite is one of the most important phases in steels, which plays a critical role in mechanical properties of steels. As a basic phase in steels, the understanding of its mechanical, physical and chemical properties is particularly desired. It is claimed to be metastable at all temperatures with respect to graphite and its saturated solution in iron.
The present research has led to successful fabrication of bulk cementite by mechanical alloying (MA) with subsequent spark plasma sintering (SPS). Bulk cementite with dimensions of up to 50 mm in diameter have been produced. The mechanical and physical properties of Fe_3C have been measured.
It was found that the color of cementite is metallic like pure iron. Its hardness is about 10GPa which is 10 times higher than that of pure iron. The Young's modulus of cementite is 190GPa and 10% smaller than that of pure iron. The electrical resistivity of cementite is 100/μΩ・cm and about 10 times higher than that of pure iron.The influence of Cr, Mn, V, Mo, Ti, Ni and Si additions substitutional to Fe on the structure and properties of cementite bulk has also been studied. It has been found that Cr, Mn, V and Mo can form alloyed cementite and stabilize it while Ti, Ni and Si destabilize or even suppress the formation of cementite. The hardness and Young's modulus of cementite were increased by the addition of both Cr and Mn. Thermal expansion coefficient was increased substantially by Cr or Mn additions. Slight decrease in Cp was observed by the addition of Cr or Mn.
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