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

研究了高温合金的包覆层形成情况，并与钛铝合金进行了对比。研究了少量氧化钇在铝涂层中的分散情况。在高温下对涂层及其氧化进行了表征。总结了以下结果。1)镍基高温合金的涂层中含有大量的钇，即使是铝包胶结后的涂层，也会导致含金属的氧化层在循环氧化中剥落。2)通过在钛铝合金上充填钇，提高了水垢与铝涂层的附着力。3)少量氧化钇在铝涂层中的分散，提高了循环氧化过程中对孔隙形成的抑制和垢体对基体的粘附性。

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.