Oxidation of the coating layr on the superalloy coated by yttrium pack cementation at high tempeartures.

本文研究了钇包铝共渗高温合金涂层的形成，并与钛铝合金进行了对比。研究了少量氧化钇在铝镀层中的分散情况。对镍基高温合金的涂层及其高温氧化进行了表征，结果表明：1）镍基高温合金的涂层中含有大量的钇，即使在包铝渗层中也是如此;导致在循环氧化中含金属的氧化物膜的析出。2）通过在钛铝合金上进行钇包渗，可提高氧化皮与铝涂层的粘附力。3）少量氧化钇在铝涂层中的分散改善了对空隙形成的抑制以及氧化皮在铝涂层中对基底的粘附。循环氧化

Formation of the coating layr has been investigated on the superalloys, compared with the titanium-aluminum alloys, coated by yttrium pack in combination with aluminum pack cementation. The dispersion of a small amount of yttrium oxide in the aluminum coating layr has been also investigated. The coating layr and its oxidation have been characterized at high temperatures.The following results are summarized.1) A large amount of yttrium in the coating layr on the nickel-base superalloy, even in case of the one that was follwed by aluminum pack cementation, results in the spallation of the oxide scale containing the metal in the cyclic oxidation.2) The adhesion of the scale to the aluminum coating layr is improved by yttrium pack cementation on the titanium-aluminum alloy.3) The dispersion of a small amount of yttrium oxide in the aluminum coating layr improves suppression of void formation and adhesion of the scale to the substrate in the cyclic oxidation.