| Project/Area Number |
16560610
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | University of Toyama |
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Principal Investigator |
MATSUKI Kenji University of Toyama, Graduate School of Science and Engineering, Professor, 大学院理工学研究部工学, 教授 (10019193)
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| Co-Investigator(Kenkyū-buntansha) |
TAKATSUJI Norio University of Toyama, 助教授 (20143844)
AIDA Tetsuo University of Toyama, 助手 (20283062)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | magnesium alloy / SiC particle reinforced composite / extrusion of cutting chips / ECAP / mechanical properties / wear resistance / superplasticity / fine grained structure / SiC粒子 / 複合材 / 熱間押出し / 高速超塑性 / リサイクル / 繰り返し押出し / 複合材料 / 形材表面性状 |
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| Research Abstract |
1.Extrusion tests on cutting chips of AZ31B and AZ91D Mg alloys were carried out at extrusion speeds (V_R) between 0.5〜5mm/s and at temperatures(T_E) of 573K and 623K.
(1)The introduction of a round corner at the die exit (R-die) was effective in improving the surface roughness of the extrusions because of a continuous and smooth metal flow.
(2)Nitrogen gas cooling suppressed the grain coarsening at surface layer due to the temperature increase during the extrusion, thus resulting good surface quality without cracks and high ductility of the extrusions even at high extrusion ram speed.
2.Extrusion tests were performed for AZ31B cutting chip compaction reinforced with SiC particles (average particle size : d_p=1.2〜2 μm, and volume fraction : V_f =0〜6%)
Agglomerates of SiC particles larger than d_p =12 μm were easy to disperse uniformly, but those of particles less than about 3 μm were difficult to disperse by the extrusion process.
3.The combined process, in which ECAP (N=7,Route B_A) was followed by the hot extrusion for the AZ31 Mg-SiC particle (d_p=3 μm, V_f =0〜6%) compaction, was effective to disperse SiC particles relatively uniformly. Moreover, very fine average grain size (d_g) of about 2 μm was obtained within the composite matrix (V_f of SiC particle:6%).
4.Mechanical properties of the composite extrusions fabricated by the combined process
(1)With increasing of volume fraction of SiC particles (d_p=3 μm) to 6%, 0.2% yield strength and wear resistance were increased but elongation was decreased.
(2)High strain rate superplasticity was obtained at strain rates higher than 10^<-2> s^<-1>.
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