This Small Business Innovation Research (SBIR) Phase I research project describes an innovative approach for Laser-Based Ultrasonic (LBU) Non-Destructive Evaluation (NDE). The proposed inspection system will allow efficient laser generation of both compression and shear waves, as well as simultaneous laser measurement of the three-component of the ultrasonic displacement. LBU has now become a valuable tool for on-line inspection, demonstrating its advantages in the steel and aerospace industries. Unfortunately, these systems do not take advantage of the whole ultrasonic information available because they are based on only the propagation of compression wave and they only measure the out-of-plane displacement. There is a strong need in NDE for both a laser generation capable of efficiently generating shear waves at normal incidence and for a laser ultrasonic receiver capable of measuring simultaneously the three-component of the ultrasonic field (i.e.: measurement of interface properties, material anisotropy or residual stress evaluation).
The ability to efficiently and remotely generate both compression and shear waves combined with the ability to simultaneously and remotely measure the three-components of the ultrasonic field will be very beneficial for on-line process control as well as for research material characterization. With this proposed LBU system, NDE inspection techniques based on shear wave detection could now be carried out remotely without mechanical contact, allowing for rapid, in-process inspection of high temperature material. The industries that will benefit from this new NDE tool include: The metal industry, the aerospace industry, the automotive industry and the coating industry.
