Abstract The CoCrAlY coatings deposited using the high velocity oxygen fuel process (HVOF) onto the Inconel 718 superalloy were employed by three different vacuum pre-oxidation heat treatments, and subsequently, the specimens were subjected to isothermal oxidation exposure testing in air at 1050 °C for up to 100 h. The spinel oxides were found in the CoCrAlY coatings during the high velocity oxygen fuel process, and subsequently, after isothermal oxidation exposure in air, both the spinel and CoO oxides were formed in the TGO of the NVHT specimen. The evolution of both the phase transformation and the thermally grown oxides' (TGO) growth rate could be significantly influenced by adjusting certain process parameters of vacuum pre-oxidation heat treatments. The TGO of the VHT specimen was predominantly composed of θ-Al2O3 and α-Al2O3; however, Co(Cr, Al)2O4 and alumina were observed in the TGO of the VHT950 and VHT1000 specimens. The θ-Al2O3 to α- Al2O3 phase transformation in the TGO of the VHT specimen could be delayed after isothermal oxidation exposure. The TGO growth rate was significantly suppressed after the vacuum pre-oxidation heat treatments, and the order of the TGO growth rate was as follows: NVHT

中文翻译：

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真空预氧化工艺参数对超音速火焰喷涂CoCrAlY涂层微观结构演变的影响

摘要 采用高速氧燃料工艺 (HVOF) 在 Inconel 718 高温合金上沉积的 CoCrAlY 涂层通过三种不同的真空预氧化热处理，随后在 1050 °C 的空气中进行等温氧化暴露试验。长达 100 小时。在高速氧燃料过程中，在 CoCrAlY 涂层中发现了尖晶石氧化物，随后，在空气中等温氧化后，在 NVHT 样品的 TGO 中形成了尖晶石和 CoO 氧化物。通过调整真空预氧化热处理的某些工艺参数，可以显着影响相变和热生长氧化物 (TGO) 生长速率的演变。VHT 试样的 TGO 主要由 θ-Al2O3 和 α-Al2O3 组成；然而，在 VHT950 和 VHT1000 试样的 TGO 中观察到 Co(Cr, Al)2O4 和氧化铝。VHT 试样的 TGO 中的 θ-Al2O3 到 α-Al2O3 相变在等温氧化暴露后可能会延迟。真空预氧化热处理后TGO生长速率明显受到抑制，TGO生长速率顺序如下：