Determination of mechanical properties of superhard amorphous, nanocrystalline, and microcrystalline materials by laser-based surface acoustic waves

Peter Hess

doi:10.1117/12.469610

7 June 2002 Determination of mechanical properties of superhard amorphous, nanocrystalline, and microcrystalline materials by laser-based surface acoustic waves

Peter Hess

Author Affiliations +

Proceedings Volume 4703, Nondestructive Evaluation and Reliability of Micro- and Nanomaterial Systems; (2002) https://doi.org/10.1117/12.469610
Event: NDE For Health Monitoring and Diagnostics, 2002, San Diego, California, United States

Abstract

Nondestructive evaluation of elastic properties of advanced materials was performed with short surface acoustic wave (SAW) pulses in the 10 MHz-300 MHz range. The elastic surface pulses were launched thermoelastically with pulsed laser radiation and detected with a piezoelectric foil transducer. This technique was used, for example, to determine the mechanical and elastic properties of superhard materials, such as microcrystalline CVD diamond films and submicrometer thick nanocrystalline films of cubic boron nitride. These results are compared with the properties of the corresponding single-crystal material, In layered systems or graded materials the introduction of a length scale leads to dispersion of the surface acoustic waves (SAWs), which allows the simultaneous determination of several properties, such as the density, Young's modulus, and Poisson ratio. In free-standing polycrystalline CVD diamond plates dispersion of elastic surface pulses was observed. This material is neither isotropic nor homogeneous because the grain size and structure vary from nucleation side to the growth side. In some samples anomalous dispersion of SAWs was observed on the nucleation side with the finer grains. Amorphous SiC_xN_y films with various compositions were investigated to compare the microscopic bonding characteristics, determined by molecular dynamics (MD) simulations, with the macroscopic mechanical properties obtained by surface acoustic wave spectroscopy (SAWS).

Citation Download Citation

Peter Hess "Determination of mechanical properties of superhard amorphous, nanocrystalline, and microcrystalline materials by laser-based surface acoustic waves", Proc. SPIE 4703, Nondestructive Evaluation and Reliability of Micro- and Nanomaterial Systems, (7 June 2002); https://doi.org/10.1117/12.469610

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available