In this tudy the results of the isothermal oxidation behaviour in air and over the temperature range 700-850°C of g-TiAl bulk alloys with additions of W (0-9.5 wt.%) and Si (0-0.4 wt.%) are reported. The specimens were prepared using an arc-melting apparatus starting from pure element powders (99.99%). The samples were tested using a thermogravimetric analysis in order to evaluate the oxidation kinetics. The microstructure an adherence of the protective scale to ally substrate were investigated using Scannin Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Auger Electron Spectroscopy (AES). In all investigated alloys the oxidation rates show the beneficial effect of the W and Si additions. The results of the study are used for a critical assessment of the oxidation mechanism and to suggest a possible approach for improving the scale adherence
Early stages of high temperature oxidation of gamma-TiAl Alloys: influence of W and Si addition
Micheli, Victor;
1998-01-01
Abstract
In this tudy the results of the isothermal oxidation behaviour in air and over the temperature range 700-850°C of g-TiAl bulk alloys with additions of W (0-9.5 wt.%) and Si (0-0.4 wt.%) are reported. The specimens were prepared using an arc-melting apparatus starting from pure element powders (99.99%). The samples were tested using a thermogravimetric analysis in order to evaluate the oxidation kinetics. The microstructure an adherence of the protective scale to ally substrate were investigated using Scannin Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Auger Electron Spectroscopy (AES). In all investigated alloys the oxidation rates show the beneficial effect of the W and Si additions. The results of the study are used for a critical assessment of the oxidation mechanism and to suggest a possible approach for improving the scale adherenceI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
