PROCESSING AND OXIDATION BEHAVIOR OF Y_5Si_3

摘要

Improvement in the oxidation resistance ofTi_5Si_3 by the addition of carbon, boron or oxygen prompted asimilar study of Y_5Si_3 were necessary to produce samplessuitable for testing. This reactivity excluded the use of carbon asa dopant. Undoped Y_5Si_3showed poor oxidation resistanceabove 700 deg C due to mechanical failure under stressesproduced by growth of the oxidation product. The productconsisted of an external layer of Y_2O_3 and an underlyinglayer rich in YSi_2. Y_5Si_3 doped with boron or oxygenshowed no improvement in oxidation resistance. Lack ofimprovement is possibly due to a notably higher stability andfaster growth rate of Y_2O_3 over SiO_2.