1991 Fiscal Year Final Research Report Summary
Development of controlled fracture forming process for advanced functional materials
| Project/Area Number |
01850155
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
金属加工(含鋳造)
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| Research Institution | University of Tokyo |
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Principal Investigator |
AIZAWA Tatsuhiko Univ. of tokyo/ Faculty of Engineering/ Associate Professor, 工学部, 助教授 (10134660)
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| Co-Investigator(Kenkyū-buntansha) |
NAGASAKI Chihiro Univ. of Tokyo/ Faculty of Engineering/ Assistant, 工学部, 助手 (90180471)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Controlled Fracture Forming / Composite Wires / Composite Layered Plates / Fine Microstructure Control / Good Sinterability / Initial Density of Mass / High Density Green / alpha-Al_2O_3 |
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| Research Abstract |
New alternative near-net shaping is indispensable to deal with ceramic, intermetallics and their composite materials since the conventional plastic working cannot be applied to these types of brittle materials. Usual powder forming technologies are sometimes insufficient to yield good-quality functional products with homogeneous properties or uniform shapes. Through our three year research project have been developed the controlled fracture forming process (abbreviated by CFFP) for ceramic composite wires and plates.
On the basis of the fundamental studies, we have found that
(1) Ni/SUS316-alphaAl_2O_3 wires with uniform diameter of 300mum can be produced up to 10 meters,
(2) starting from the lower initial density alpha-Al_2O_3 pre-sintered billet, most of CFFP is governed by the shear fracture process with the fractured particle rearrangement and flow under the compressive pressure constraint,
(3) the average critical reduction both in wiring and plate forming approaches 90-95%, where the green density of mass becomes 90-92% T. D. and the average particle size 0.3mum for the initial particle diamete 0.9mum,
(4) good sinterability is attained by CFFP-induced microstructural control : the sintering temprature can be lowered by 100-200ﾟC, the grain growith is surppressed, and final density reaches 99% T. D. and more.
Hence, this productive technology should be recommended as the candidate future forming method to realize nearnet shaping together with microstructural control for fine ceramics without binders and glasses.
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