ADVANCES ON NDT METHODS AND TECHNOLOGIES FOR EARLY STAGE DIAGNOSIS OF MATERIALS

摘要

The early stage diagnoses of material lattices is becoming a crucial requirement where investigation methods and technologies are faced with both aging of components and materials. The mixing effects of wear, fatigue, temperature variation and environment conditions translate into variations of the atomic flux rate and internal rearrangement of grain size and boundaries of lattices. The related lattice measurements (e.g. the d-.spacing is one important among others) become the only one usable for early stage diagnoses of the lattice structural integrity. When such a diagnoses are the base to identify the qualification of material for the use or the re-qualification for the maintenance in the use, new technologies are required, with methods and appropriate concepts shall be used.The authors bid here to describe shortly the historical evolution of methods and techniques since the 70's, along with the basic tests performed during the early 90's of the past century. The technological follow up from those tests is reported along with some results which indicate the significant step up of the most recent technology toward the early stage diagnosis of material via on site x-ray diffraction. Further foreseeable development and advances are also mentioned.