Thermal shock testing of ceramics with pulsed laser irradiation
Thermal shock testing of ceramics with pulsed laser irradiation
Arguements are presented showing that the resistance to thermal stressing ("thermal shock") under pulsed thermal energy deposition by various kinds of beam irradiations is approximately proportional to $\phi \sqrt{tp}$, where $\phi_{a}$ is the absorbed power density and tp is the pulse len...
Saved in:
Personal Name(s): | Benz, R. |
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Naoumidis, A. / Nickel, Hubertus | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Kernforschungsanlage Jülich, Verlag
1986
|
Physical Description: |
VI, 34 p. |
Document Type: |
Report Book |
Research Program: |
ohne Topic |
Series Title: |
Berichte der Kernforschungsanlage Jülich
2056 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Arguements are presented showing that the resistance to thermal stressing ("thermal shock") under pulsed thermal energy deposition by various kinds of beam irradiations is approximately proportional to $\phi \sqrt{tp}$, where $\phi_{a}$ is the absorbed power density and tp is the pulse length, under conditions of diffusivity controlled spreading of heat. In practical beam irradiation testing, incident power density, $\phi$, is reported. To evaluated the usefulness of $\phi \sqrt{tp}$ as an approximation to $\phi \sqrt{tp}$, damage threshold values are reviewed for different kinds of beams (electron, proton, and laser) for a range of tp values 5x10$^{-6}$ to 2s. Ruby laser beam irradiation tests were made on the following ceramics : AIN, BN, graphite, $\alpha$-SiC, $beta$-SiC coated graphites, ($\alpha + \beta$)Si$_{3}$N$_{4}$, CVD (chemical vapor deposition) TiC coated graphite, CVD TiC coated Mo, and CVD TiN coated IN 625. The laser beam pulse lengths investigated were 9x10$^{-4}$ (normal) and 5x10$^{-6}$s (saturable dye Q-switched) and the power densities ranged from 25 to 4000 kW/cm$^{2}$ corresponding to $\phi \sqrt{tp}$ values of 0.8 to 8.8 kJ/cm$^{2}$s$^{1/2}$. |