The Application of Angular Profile of Ultrasonic Backscattering on the Layered Substrate

The use of layers on substrates such as many aircraft structures, space vehicles and infrastructures has enhanced their performance. One of the obvious advantages of a layer on a substrate is in the separation of the substrate from ambient environment so that the substrate is not directly under attack by the environment. However, the surface problems such as not only roughness, and cracks but also an imperfection bonding between a layer and a substrate are covered by surface treatments and can degrade the performance of layered substrates and thus reduce their service life. The present and future importance of these materials demands that unique methods be developed for their testing and evaluation