【摘要】 采用电弧离子镀技术在铸造Ni基高温合金K17上沉积NiCrAlY涂层 ,测定了K17合金和NiCrAlY涂层在90 0℃～ 110 0℃的氧化动力学曲线 .实验结果表明 :K17合金和NiCrAlY涂层在不同温度静态空气中氧化动力学曲线基本符合抛物线规律 .90 0℃和 10 0 0℃时 ,K17合金上沉积NiCrAlY涂层后 ,明显改善了合金的抗氧化性 .110 0℃时 ,涂层的保护作用不如 90 0℃和 10 0 0℃ .90 0℃氧化时 ,NiCrAlY涂层氧化膜由α -Al2 O3 和Cr2 O3 组成 ;10 0 0℃氧化时 ,氧化初期 ,NiO、Cr2 O3 和Al2 O33种氧化物同时生成 .随着氧化的进行 ,不仅氧化膜增厚 ,而且发生较复杂的反应 ,氧化膜的相组成发生变化 .随着氧化温度升高 ,涂层和基体之间元素扩散加剧 ,Ti从基体扩散到涂层表面形成氧化物是导致涂层抗氧化性降低的原因之一 .氧化膜从涂层上剥落下来 ,也导致了涂层抗氧化能力降低更多还原

【Abstract】 NiCrAlY coatings were prepared on the cast Ni-base superalloy K17 using arc ion plating.After vacuum heat treatment,the coating became more uniform and smoother.The oxidation kinetic curves of the alloy K17 without and with coating were obtained.The results indicated that the oxidation resistance of the alloy K17 was evidently improved with NiCrAlY coatings at 900-1000℃.The efficiency of the coating exposed at 1100℃ was not as good as that at 900 and 1000℃.The oxide scales mainly consisted of α-Al 2O 3 and Cr 2O 3 at 900℃.In the initial oxidation stage at 1000℃,three kind of oxide,NiO,Cr 2O 3 and α-Al 2O 3 formed simultaneously.With the oxidation continuing,not only the thickness of oxide scale increased,but also complex reaction produced.As oxidation temperature rising,the interdiffusion between the coatings and substrates was enhanced.Ti atoms diffused from the substrate outwards to the surface of coating to form its oxide,which was one of the reasons of the decrement of oxidation resistance.The oxidation resistance of NiCrAlY coating was decreased due to the spallation of oxides.更多还原