Measurement of elastic-stiffness tensor of an anisotropic thin film by electromagnetic acoustic resonance.
This paper presents a contactless methodology for determining all independent elastic-stiffness coefficients Cij of a transverse isotropic thin film: C11, C12, C13, C33, and C44. The electromagnetic-acoustic-resonance technique measures the acoustic resonance frequencies of a film-coated specimen with a high accuracy, better than 10(-5), which enables determining the film Cij with the known substrate Cij. The measurement takes two steps. First, through-thickness resonance frequencies of longitudinal and shear modes are measured to determine C33 and C44, and the film thickness. Then, remaining three coefficients are deduced from measurements of the free-vibration resonance frequencies of the layer parallelepiped specimen. Simulations and experiments with monocrystal copper and titanium confirm the reliability of the resultant film Cij within 5%, when the film thickness is more than 0.5% of the substrate.
Ogi
Hirotsugu
H
Graduate School of Engineering Science, Osaka University, Toyonaka, Japan. ogi@me.es.osaka-u.ac.jp
Shimoike
Goh
G
Takashima
Kazuki
K
Hirao
Masahiko
M