1987 Fiscal Year Final Research Report Summary
Investigation on Deformation and Fracture Behavior of Sintered Materials from a viewpoint of Composite
| Project/Area Number |
61550053
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械材料工学
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| Research Institution | Nagoya University |
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Principal Investigator |
TOHOGO Keiichiro Nagoya University, School of Engineering Research Associate, 工学部, 助手 (10155492)
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| Co-Investigator(Kenkyū-buntansha) |
MORI Kaname Nagoya University, School of Engineering Research Associate, 工学部, 助手 (70023207)
MIYATA Takashi Nagoya University, School of Engineering Associate Professor, 工学部, 助教授 (20023228)
OTSUKA Akio Nagoya University, School of Engineering Professor, 工学部, 教授 (60022993)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Sintered Materials / Two-Phase Sintered Materials / WC-Co Hardmetal / Mechanical Model / Composite Materials / Deformation Behavior / Fracture Mechanics / 破壊機構 |
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| Research Abstract |
The sintered materials are macroscopically homogeneous but microscopically heterogeneous. So, deformation and fracture behavior of the sintered materials is controlled by the heterogeneity. In this investigation, tests of WC-Co hardmetals have been carried out on the deformation and fracture behavior, and a mechanical model for estimation of the deformation of two-phase sintered materials has been devaloped. Fracture mechanism of WC-Co hardmetals was investigated based on the results of tensile tests, compressive tests and fatigue tests, and fracture surface was characterized based on SEM observation and EDX analysis. Taking account of the experimental results, the mechanical model of two-phase sintered materials, which can predict not only overall elastic moduli and overall instantaneous elastic-plastic moduli but also microscopic stress/strain of each phase, was developed. This model was applied to estimation of the deformation behavior of WC-Co hardmetals with various volume fraction of Co. The analytical results of the overall elastic moduli and the overall stress-strain relation under uniaxial tensile tests agreed well with the experimental results. The variation of the transverse rupture strength of WC-Co hardmetals, as a function of Co volume fraction, was explained from a viewpoint of microscopic stress/strain. Further, macroscopic stress/strain field and microscopic stress/strain field around a crack tip in WC-Co hardmetals was analyzed by the finite element method, in which the mechanical model was employed as the constitutive relation. The fracture behavior from a crack tip in WC-Co hardmetals was discussed based on the analytical results.
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