Improving metal fatigue prediction

 - October 15, 2007, 10:59 AM

Boise, Idaho-based Positron Systems has received a Small Business Innovative Research grant by the Office of Naval Research to enhance its Photon
Inducted Positron Annihilation (PIPA) technology. PIPA detects material fatigue and provides remaining useful-life assessments on turbine propulsion systems and drivetrain bearings. The goal is for the predictive capabilities of PIPA to help lead to the use of improved materials, enhanced designs and lower life-cycle costs in commercial and military aircraft development programs.

The PIPA process involves penetrating materials with a photon beam generated by a linear accelerator. This process creates positrons, which are attracted to nano-size defects in the material. Eventually, the positrons collide with electrons in the material and are annihilated, releasing energy in the form of gamma rays. The gamma ray energy spectrum creates a distinct and readable signature of the size, quantity and type of defects present in the material.

PIPA can detect a wide variety of damage types in many materials. Because PIPA examines materials at the atomic level, it can detect damage at its earliest stage, before visible cracks appear. The technology can also pinpoint the remaining useful life of a component and detect damage in second-layer materials.