Project/Area Number |
02650462
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Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
Physical properties of metals
|
Research Institution | Kyoto University |
Principal Investigator |
NUMAKURA Hiroshi Kyoto University, Faculty of Engineering Instructor, 工学部, 助手 (40189353)
|
Project Period (FY) |
1990 – 1991
|
Project Status |
Completed (Fiscal Year 1991)
|
Budget Amount *help |
¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
|
Keywords | Hydrogen / Nickel-based Alloys / Internal Friction / Magnetic Aftereffect / 磁歪 / 磁壁移動 |
Research Abstract |
1. Development of a high-frequency internal friction measurement apparatus An electric circuit for the excitation and detection of flexural vibration of a reed specimen has been made, and has been set into the apparatus. The level of the detected electrical signal is not sufficiently high ; further improvements are necessary. 2. Relaxation due to hydrogen-substitutional impurity complexes in nickel Relaxation due to local reorientation of hydrogen in Ni-based dilute alloys has been investigated by internal friction and magnetic aftereffect measurements. The internal friction of a Ni-2%Ti-H single crystal suggest that hydrogen atoms are located not at the nearest neighbour octahedral position to the substitutional Ti atom. The height of the relaxation peak is found to be decreased by an application of external magnetic field. It is possible that the relaxation process involves some mechanisms of magnetic origin. 3. Relaxation due to hydrogen in ordered/disordered Ni_3Fe alloys. Internal friction and magnetic aftereffect have been measured also on ordered and disordered Ni_3Fe alloys charged with hydrogen. The dependence of the height of the hydrogen-related internal friction peak, as well as the effect of external field on the peak height, is similar to the one observed for the dilute alloys. Contributions of magnetic energy to the relaxation must be studied further in detail.
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