1997 Fiscal Year Final Research Report Summary
NOVEL APPARATUS USING SCANNING LASER EXTENSOMETRY FOR HIGH-TEMPERATURE MATERIALS TESTING AND ITS APPLICATION TO MECHANICAL SPECTROSCOPY STUDIES ON METAL MATRIX COMPOSITES
| Project/Area Number |
08555161
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
Structural/Functional materials
|
|---|
| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
|---|
Principal Investigator |
WAKASHIMA Kenji Professor, Precision and Intelligence Laboratory, Tokyo Institute of Technology, 精密工学研究所, 教授 (70016799)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TSUKAMOTO Hideaki Research Associate, Precision and Intelligence Laboratory, Tokyo Institute of Te, 精密工学研究所, 助手 (30227376)
|
|---|
| Project Period (FY) |
1996 – 1997
|
| Keywords | Scanning Laser Extensometry / High-Temperature Mechanical Testing / Cyclic Loading / Mechanical Spectroscopy / Anelasticity / Dynamic Young's Modulus / Internal Friction / Metal Matrix Composites |
|---|
| Research Abstract |
In this two-year research project, supported by a Grant-in-Aid for Scientific Research (A) (2) from the Ministry of Education, Science, Sports and Culture under Contract 08555161, we have constructed a novel experimental setup for high-temperature materials testing on a standard servo-hydraulic machine ; it features a high-precision extensometric system based on a portable "scanning laser caliper" and enabls us to measure the dynamic anelastic response of a material over a temperature range from 300 to 1373 K under low-frequency (1cHz-1dHz) subrresonant conditions of cyclic uniaxial loading. Using the apparatus, the measurements of dynamic Young's modulus and internal friction have been carried out on metal-ceramic composite materials including Al-SiC,Al-9Al_2O_32B_2O_3 and Ni-ZrO_2 systems ; the experimental data on these materials all show clear evidence of anelastic relaxation in two well-separated temperature all show clear evidence of anelastic relaxation in two well-separated tem
… More
perature ranges, i.e.two internal friction peaks are observed together with marked decreases in dynamic Young's modulus. Kinetic aspects of these relaxation phenomena have been analyzed in detail ; this involves the determination of the activation energy and pre-exponential factor of the relaxation time from the frequency dependence of the peak-top temperature of internal friction, and the comparison of the experimentally determined kinetic parameters with predictions of theoretical models. The analysis identifies one of the observed peaks as the well-known Ke's peak due to viscous grain-boundary sliding. As a possible origin of the remaining peak, we raise the stress-directed diffusive mass flow along metal-ceramic phase boundaries, and make a micromechanics-based calculation to derive theoretical expressions for the resulting dynamic Young's modulus and internal friction of composite materials. The comparison between theory and experiment also proves the actuality of this relaxation mechanism. Less
|
Research Products
(6 results)
