Reflection of a Gaussian ultrasonic beam from Al2O3 layer–stainless steel in water at the Rayleigh angle

The problem of ultrasonic wave reflection at a Rayleigh angle from Al2O3 layer–stainless steel in water was investigated. The so-called leaky Rayleigh velocity was measured by using an optical schlieren technique to identify the Rayleigh angle. The magnitude of the measured leaky Rayleigh velocity for the coated surface is smaller than the corresponding leaky Rayleigh velocity for either stainless steel or for Al2O3.