| Project/Area Number |
10355030
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| Research Category |
Grant-in-Aid for Scientific Research (A).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Material processing/treatments
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| Research Institution | Hiroshima University |
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Principal Investigator |
KUROKI Hidenori Faculty of Engineering, Hiroshima University, Professor, 工学部, 教授 (80037853)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Hiroyuki Faculty of Engineering, Hiroshima University, Research Associate, 工学部, 助手 (90284158)
SASAKI Gen Faculty of Engineering, Hiroshima University, Associate Professor, 工学部, 助教授 (30192595)
SHINOZAKI Kenji Faculty of Engineering, Hiroshima University, Associate Professor, 工学部, 助教授 (70154218)
FUKAYA Yasuhiro Kinki University Faculty of Engineering, Professor, 工学部, 教授 (40268454)
TASHIMA Shunzo Faculty of Education, Hiroshima University, Associate Professor, 教育学部, 助教授 (40136130)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥30,200,000 (Direct Cost: ¥30,200,000)
Fiscal Year 2000: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1999: ¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1998: ¥23,700,000 (Direct Cost: ¥23,700,000)
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| Keywords | alumina / WC / low-defect / defect removing function / compactability / compacting velocity / highstrength / 着肉速度 / 沈降 / 高遠心力 |
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| Research Abstract |
The contents of the present research is divided into three sections. Firstly, the compacting mechanism of High-Speed Centrifugal Compaction Process (HCP) is investigated. Then, the HCP alumina are made under a variety of compacting condition, and the effect of the condition on the properties of sintered alumina is clarified. And finally, the WC sintered material is made by HCP.
The results are as follows :
(1) Since the compacting mechanism of HCP is entirely different from that of pressure casting, HCP possesses much higher compacting velocity than pressure casting. The compacting velocity of HCP increases in proportion to the square of rotational speed, but it does not affected by the initial concentration of slip. Therefore, the efficiency of the production can be improved using a easy-to-prepare dilute slip and higher rotational speed. The compacting velocity of HCP can be estimated quantitatively applying Kynch's theory.
(2) The packing density of HCP green compact increases as rolational speed increases. In addition, the defects within the slip are removed more effectively at higher rotational speed. Thus, a dense and low defect green compact can be obtained with higher rotational speed.
(3) The high strength of HCP alumina is due to the fine and low-defect sintered microstructure. The HCP alumina possesses one of the most low-defect microstructure among ever fabricated or commercially available aluminas.
(4) The above mentioned characteristics are also effective for the compaction of WC fine powder. By dispersing the WC powder in heptane, a dense green compact is obtained within a short time. This green compact can be sintered to almost 100% in relative density without adding cobalt, and it shows high hardness of Hv 2300.
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