中文摘要：

采用超音速喷涂工艺在Ni基高温合金GH99上制备NiCoCrAlY粘结层,研究超音速火焰喷涂工艺对热障涂层抗氧化性能的影响。结果表明：等离子喷涂粘结层表面存在着大量的尖角和钩状的突出颗粒,而超音速喷涂粘结层表面较为平整,内部黑色氧化物较少。超音速喷涂涂层在氧化15min后表面生成一层较为致密的颗粒状氧化物。超音速喷涂试样在前40min氧化增重速率快于等离子喷涂试样,此后变得缓慢,而等离子喷涂试样氧化速率依然较高。超音速喷涂的涂层在氧化300h后热生长氧化物（Thermally grown oxide,TGO）出现分层,TGO内层组织致密,TGO外层组织存在大量的孔洞和间隙。超音速喷涂工艺使热生长氧化物瞬态氧化阶段时间缩短,稳态氧化阶段时间延长,减少了氧化缺陷的产生,有效地提高了涂层抗高温氧化性能。

英文摘要：

MCrAlY bond coat is deposited onto GH99 high-temperature alloy by using high velocity oxygen fuel technique.The influence of this technique on the oxidation resistance is studied.The experimental results show that lots of sharp-angled and hooked grains exist on the surface of the APS-bond coat,while the surface of HVOF-MCrAlY is relatively smooth and with less internal black oxide.A layer of compact granular oxide forms on the surface of HVOF-MCrAlY after 15 min oxidation,the weight gain of HVOF sample is faster than that of the APS sample in the first 40min oxidation,then becomes slowly,while the APS sample still has high oxidation rate.HVOF sprayed coating of thermally grown oxide（TGO） appears delamination after 300 hours oxidation,TGO layer close to bond coat has dense organization,TGO layer close to top coat has lots of holes and gaps in it.Due to high velocity oxygen fuel technique,time for TGO coming into steady-state oxidation stage is shortened and the period of steady-state oxidation becomes longer.The high temperature oxidation resistance of coating could be improved obviously.