Bestimmung des Einflusses von Kriechschädigungen auf die Rayleighwellengeschwindigkeit an der Legierung Alloy 800 H mittels Akustischer Rastermikroskopie

In materials loaded at high temperatures and under stationary conditions irreversel damage can occur due to creep mechanisms. The damage like micropores of cracks results in a reduction of the material's elastic properties which can be measured as a reduction of the ultrasound velocity of the material. The change of the elastic properties can be determined with high lateral resolution by acoustic microscopy. This is demonstrated at the Alloy 800 H loaded at 800 C and 45 MPa. At a frequency of 1 GHz the Rayleighwave velocity was measured as a function of the damge grade. The results are compared to time of flight measurements done in the MHz-regime.