| Project/Area Number |
10555230
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
Structural/Functional materials
|
|---|
| Research Institution | Nagoya University |
|---|
Principal Investigator |
MURATA Yoshinori Nagoya Univ., Materials Science and Eng., Associate Professor, 工学研究科, 助教授 (10144213)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FUKUI Yutaka Hitachi Research Lab., Chief Researcher, 日立研究所, 主管研究員
YUKAWA Hiroshi Nagoya Univ., Materials Science and Eng., Research Associate, 工学研究科, 助手 (50293676)
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
|
| Budget Amount *help |
¥11,000,000 (Direct Cost: ¥11,000,000)
Fiscal Year 1999: ¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 1998: ¥6,400,000 (Direct Cost: ¥6,400,000)
|
|---|
| Keywords | superalloy / nickel alloy / high-temperature strength / hot-corrosion resistance / oxidation resistance |
|---|
| Research Abstract |
The purpose of this research is to develop nickel based superalloys possessing excellent properties, such as high temperature strength, hot-corrosion resistance, thermal fatigue resistance, etc. For this purpose, we tried to employ a new method, which utilized the segregation phenomenon to obtain a composite structure consisting of two regions containing different sizes of the γ' phase. Firstly, high Cr nickel based superalloys were developed, and the mechanical properties and surface stability of the alloys were examined. The results are obtained as follows ;
(1) In spite of high Cr content of 12mass%, hot corrosion resistance is different considerably among the experimental alloys. Good hot-corrosion resistance is obtained in a high Ti/Al compositional ratio in alloys. (2) High temperature oxidation resistance is obtained in a low Ti/Al compositional ratio, which is in inverse relation to the case of hot-corrosion resistance. This result indicates that an optimum Ti/Al compositional ratio will exist to obtain an excellent resistance to both hot corrosion and oxidation. (3) The experimental alloys exhibit shorter in creep rupture life in the condition of 1313K/137MPa than CMSX-4 containing 3%Re alloy, but two experimental alloys exceed the rupture life of CMSX-4 in the condition of 1193K/196MPa. This fact shows that a superalloys. (4) Cobalt plays a role to increase creep rupture life at high stress levels but it does not play anymore at low stress levels. (5) The experimental alloys having the composite structure exhibit low thermal fatigue resistance, indicating that homogeneous composition in alloys is necessary for a good indication of the thermal fatigue resistance of them.
|
