MEASURING THE DEFORMATION OF CRYSTALLINE MATERIALS DUE TO THE IMPACT OF ERODING PARTICLES

The continuous impact of particles on to a material surface results in erosion. In technical applications particles with a diameter from som e microns up to some millimetres impinge on to surfaces with velocitie s up to some ten metres per second. In order to investigate experiment ally the erosion at the surface of crystalline materials plates of aus tenitic steel are locally damaged due to the repeated impact of solid particles. The amplitude of the surface deformation which is excited b y the impact of a single particle is only 10(-9)-10(-7) m. The surface deformation which is caused by such an impact is measured by means of double-pulse holographic interferometry. Because of the small amplitu de of the surface waves quasi-heterodyne holographic interferometry is required. The areas of initial wear of the materials can be recognize d by the disturbed propagation of the surface waves.