Project/Area Number |
16360357
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Material processing/treatments
|
Research Institution | The University of Tokyo |
Principal Investigator |
YANAGIMOTO Jun The University of Tokyo, Institute of industrial Science, Professor (90220194)
|
Co-Investigator(Kenkyū-buntansha) |
SUGIYAMA Sumio the University of Tokyo, Institute of Industrial Science, Research Associate (90242122)
|
Project Period (FY) |
2004 – 2007
|
Project Status |
Completed (Fiscal Year 2007)
|
Budget Amount *help |
¥15,650,000 (Direct Cost: ¥15,200,000、Indirect Cost: ¥450,000)
Fiscal Year 2007: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2006: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2004: ¥10,900,000 (Direct Cost: ¥10,900,000)
|
Keywords | Severe plastic deformation / Ultrafine-grained steel / Composite material / Carboon nanotube / Extrusion / Controlled cooling / Mechanical properties / Conductivity / 1パス強加工 / 鉄鋼材料 / 微細結晶粒 / フェライト組織 / EBSP / 機能素材 / スーパーファイン / 一発創成 / フェライト組織微細化 / 低温熱間加工 / 内部組織変化 / 引張試験 / 冷間圧縮試験 / 冷間鍛造性 / 押出し / 組織制御 / 超微細粒鋼 / ARB法 / ECAP法 |
Research Abstract |
We developed an extrusion process with a cross-sectional area reduction as 'single-pass severe plastic forming (S2PF)' process for producing ultrafine-grained plain carbon steels. We investigated the microstructure and mechanical properties of fine-grained 0.2% carbon steels extruded at 1100-600℃. Ultrafine ferrite grains with a grain size of 1.2 micro meter were generated at the surface of the materials extruded at 700℃. The materials extruded at 800, 700 and 600℃ were investigated by scanning electron microscopy, electron backscattering diffraction analyses, tensile tests and compression tests. Extrusion at 700℃, which is near the austenite-ferrite transformation temperature (Ar3), produced a material sample with a diameter of 5 mm, an average ferrite grain size of approximately 2 micro meters, a tensile strength of about 700MPa, a uniform elongation of about 15% and a good cold-forging property. An 'single-pass severe plastic forming (S2PF)' is then applied to the forming of composite material. Here, light-weight structural metal, Aluminum A6061, is used as the base metal and multi-walled carbon nanotube (CNT) is selected as the additional material. Uniformly-distributed 1wt% CNT in A6061 matrix is successfully manufactured by the extrusion process, which directly enables compaction and sintering at the same time utilizing 'single-pass severe plastic forming (S2PF)'. Electrical conductivity is measured and it is elevated up to 125% of the matrix base metal A6061.
|