【摘要】 在M 3 8镍基高温合金上电镀Pd - 2 0mass%Ni合金 ,采用低压固体粉末包埋渗铝方法制备钯改性铝化物涂层 ,XRD分析表明 ,涂层主要由 β - (Ni,Pd)Al相组成 .利用TGA、SEM等方法 ,研究了涂层在 80 0℃、90 0℃和110 0℃的高温氧化行为表明 ,β- (Ni,Pd)Al涂层恒温氧化动力学遵循抛物线规律 ;10 0 0℃氧化动力学则不遵循抛物线规律 .在 80 0℃和 90 0℃下 ,β - (Ni,Pd)Al涂层表面氧化产物包括α -Al2 O3、θ -Al2 O3和少量的γ -Al2 O3;在10 0 0℃下 ,涂层表面存在α -Al2 O3和θ -Al2 O3两种氧化物 ;在 110 0℃下 ,涂层表面氧化产物主要是α -Al2 O3.此外 ,在各温度下涂层表面的氧化产物中都含有少量的TiO2 ,随着温度升高 ,其含量增加 .更多还原

【Abstract】 Ni,Pd)Al coating prepared by low pressure pack cementation on nickel-based superalloy M38 predeposited with Pd-20mass% Ni alloy,is composed of β-(Ni,Pd)Al phase.The isothermal oxidation behavior of the coating at 800℃-1100℃ was investigated by TGA、SEM.It was found that the oxidation kinetics accorded preferably with parabolic law at 800℃,900℃ and 1100℃,but not at 1000℃.θ-Al 2O 3 and α-Al 2O 3 were the main oxidation product and γ-Al 2O 3 was very little at 800℃ and 900℃,θ-Al 2O 3 and α-Al 2O 3 at 1000℃,and only α-Al 2O 3 at 1100℃.In addition,there was a little TiO 2 on the coating surface,and the content of TiO 2 was increasing with rising of the temperature.更多还原