Novel thermal-acoustic point transducer

Abstract

<p>The Air Force has a continuing need to develop materials which can withstand high temperatures and stresses. The quality of the grain boundaries, i.e. the ability of the grain boundary to resist slip, is one of the most important factors in determining how well a material will resist creep and high stresses. While there are techniques which can image grain boundaries (ultrasonic microscopy and scanning electron microscopy of etched specimens), there is no known method to assess their quality. Thus there is a need to develop a technique to measure the quality of grain boundaries.</p>