scholarly journals Mechanical properties of fullerite and diamondlike carbon films using surface acoustic waves and nanoindentation

Author(s):  
Asta Richter ◽  
Ronald Ries
1999 ◽  
Vol 593 ◽  
Author(s):  
A.C. Ferrari ◽  
J. Robertson ◽  
R. Pastorelli ◽  
M.G. Beghi ◽  
C.E. Bottani

ABSTRACTThe elastic constants of thin Diamond-Like Carbon (DLC) films supply important information, but their measurement is difficult. Standard nanoindentation does not directly measure the elastic constants and has strong limitations particularly in the case of hard thin films on softer substrates, such as tetrahedral amorphous carbon on Si. Surface acoustic waves provide a better mean to investigate elastic properties. Surface Brillouin scattering (SBS) intrinsically probes acoustic waves of the wavelength which is appropriate to test the properties of films in the tens to hundreds of nanometers thickness range. SBS can be used to derive all the isotropic elastic constants of hard-on-soft and soft-on-hard amorphous carbon films of different kinds, with thickness down to less than 10 nm. The results help to resolve the previous uncertainties in mechanical data. The Young's modulus of tetrahedral amorphous carbon (ta-C) turns out to be lower than that of diamond, while the moduli of hydrogenated ta-C (ta-C:H) are considerably lower than those of ta-C because of the weakening effect of C-H bonding.


Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Jihyun Jun ◽  
Hogeon Seo ◽  
Kyung-Young Jhang

The structures in high-temperature environments are prone to undergo hardening and embrittlement as a result of thermal aging; this can cause variations in their mechanical properties. Because these changes occur at the microstructural level, it is difficult to evaluate them through linear ultrasonic techniques. In this work, a surface acoustic wave (SAW) was used to measure and compare the acoustic nonlinearity and mechanical properties of Al6061 alloys heat-treated at 220 °C for different durations (0 min, 20 min, 40 min, 1 h, 2 h, 10 h, 100 h, 1000 h). The SAW was generated by a pulsed laser and then received by an interferometer. Moreover, the yield strength, ultimate strength, and elongation to failure were measured by tensile tests. The results demonstrate that the critical variations in the mechanical properties can be detected by monitoring the variation features in the acoustic nonlinearity. Transmission electron microscopy images were captured to observe the microstructural changes, which shows that the acoustic nonlinearity varied according to the change in the precipitation phase. This supports the acoustic nonlinearity measurement using the laser-generated SAW being an effective technique for the fully noncontact nondestructive evaluation of material degradations as well as changes in mechanical properties.


2009 ◽  
Vol 18 (5-8) ◽  
pp. 768-771 ◽  
Author(s):  
Juequan Chen ◽  
Chris J. Lee ◽  
Eric Louis ◽  
Fred Bijkerk ◽  
Reinhard Kunze ◽  
...  

1999 ◽  
Vol 594 ◽  
Author(s):  
A. C. Ferrari ◽  
J. Robertson ◽  
R. Pastorelli ◽  
M. G. Beghi ◽  
C. E. Bottani

AbstractThe elastic constants of thin Diamond-Like Carbon (DLC) films supply important information, but their measurement is difficult. Standard nanoindentation does not directly measure the elastic constants and has strong limitations particularly in the case of hard thin films on softer substrates, such as tetrahedral amorphous carbon on Si. Surface acoustic waves provide a better mean to investigate elastic properties. Surface Brillouin scattering (SBS) intrinsically probes acoustic waves of the wavelength which is appropriate to test the properties of films in the tens to hundreds of nanometers thickness range. SBS can be used to derive all the isotropic elastic constants of hard-on-soft and soft-on-hard amorphous carbon films of different kinds, with thickness down to less than 10 nm. The results help to resolve the previous uncertainties in mechanical data. The Young's modulus of tetrahedral amorphous carbon (ta-C) turns out to be lower than that of diamond, while the moduli of hydrogenated ta-C (ta-C:H) are considerably lower than those of ta-C because of the weakening effect of C-H bonding.


1989 ◽  
Vol 65 (5) ◽  
pp. 1918-1922 ◽  
Author(s):  
Shigeki Hoshino ◽  
Kazutaka Fujii ◽  
Nobuaki Shohata ◽  
Hirotaka Yamaguchi ◽  
Yuji Tsukamoto ◽  
...  

2000 ◽  
Vol 9 (8) ◽  
pp. 1430-1434 ◽  
Author(s):  
S. Zhgoon ◽  
Q. Zhang ◽  
S.F. Yoon ◽  
A. Revkov ◽  
B. Gan ◽  
...  

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