| Project/Area Number |
04403014
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
金属材料(含表面処理・腐食防食)
|
|---|
| Research Institution | Tohoku University, Institute for Materials Research |
|---|
Principal Investigator |
MASUMTOTO Tsuyoshi Tohoku Univ., Institute for Materials Research, Professor, 金属材料研究所, 教授 (20005854)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KIKUCHI Yoshio Tohoku Univ., Institute for Materials Research, Research Associate, 金属材料研究所, 助手 (30204837)
TSAI An-pang Tohoku Univ., Institute for Materials Research, Assosiate Professeor, 金属材料研究所, 助教授 (90225681)
KIMURA Hisamichi Tohoku Univ., Institute for Materials Research, Research Associate, 金属材料研究所, 助手 (00161571)
|
|---|
| Project Period (FY) |
1992 – 1994
|
| Project Status |
Completed (Fiscal Year 1994)
|
| Budget Amount *help |
¥17,700,000 (Direct Cost: ¥17,700,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1993: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1992: ¥13,900,000 (Direct Cost: ¥13,900,000)
|
|---|
| Keywords | Nano-aluminum phase / amorphous phase / aluminum-based alloys / dispersed structure / graim growth / ナノAl相 / Al基合金 / 高比強度 / 結晶化 / 液体急冷法 / 低温焼なまし / ナノAl粒子 / 分散強化 / 固溶体型元素 / 部分結晶化 / 耐熱強度 |
|---|
| Research Abstract |
In this project, we have developed a novel type of metallic material that is an amorphous matrix with dispersion of nano-crystalline particles. The structure was obtained in several Al-based alloys (Al>87%) by annealing amorphous phase at low temperature (-400K). This materials with precipitation of fcc-Al revealed tensile strength and ductility higher than those for full amorphous phase. Furthermore, in a systematic investigations, it was found that addition of 3at% Cu (or Ag) remarkably improved the mechanical strength. For example, for Al_<87>Ni_7Cu_3Ce_3 alloy, the tensile strength of as-quenched amorphous phase is about 900MPa and it goes up to about 1200MPa after subsequent annealing. Annealing induced increase in tensile strength is caused by the dispersion of fcc-Al particles with size of 5-10nm in the amorphous matrix. The precipitation of fcc-Al was identified to be a growth process of nanocrystalline grains in amorphous phase. The grain process was only observed in the amorphous alloy with Al>87at%, indicating a number nuclei have pre-existed in an Al-enriched area in the original amorphous state. This has been confirmed by small angle X-ray diffraction. In the characterization by atom probe field ion microscopy, Ce seems to be strongly segregated in the fcc-Al/amorphous interface. It was concluded that the segregation of Ce (the atom with large size) supresses the growth of fcc-Al grains and enhances the tensile strength of the material.
|
