It is well known that the nonlinear elastic behavior of solids modulates transmitting ultrasonic wave [1], Higher harmonics of the fundamental frequency are generated, especially second harmonics describing the deviation from the linear elastic behavior of the solid. Some effects were also observed in ultrasonic velocity [2] and transmission of ultrasound [3] due to the nonlinear elastic behavior of interfaces. In general, reduced bonding of joined materials causes a strong nonlinear elastic behavior [4]. We exploit this for the observation of the modulation of the ultrasonic wave at interfaces [5,6]. There exist several models based on a macroscopic description of the interface restoring forces using for example the extended Hooke’s Law [7] or nonlinear spring relations [3,8].