物理蒸鍍Ni-Al鍍膜與高速火焰融射MCrAlY塗層之抗熱循環氧化性比較

Comparison of Thermal Cyclic Oxidation of the PVD Ni-Al and HVOF-MCrAlY Coatings

在高溫渦輪引擎與發電機組的葉片及燃燒室中，熱融射MCrAlY介層與YSZ絕熱面層是目前最常採用的保護及維修方式。在新一代的面層研究開發中，採用EB-PVD所製作YSZ絕熱面層，已被證實可提供較熱融射YSZ絕熱面層更長的使用壽命。另一方面，在新一代介層的研究開發中，以CVD鋁化製程製備出的PtAl或NIAl介層較熱融射MCrAlY介層為強的抗高溫氧化與附著性。因此，若能開發出以PVD製程所製備的介層材料，就能與PVD絕熱面層製程相整合，既避免CVD製程的環保問題，同時又有較融射製程為佳的複雜尺寸工件的處理能力與鍍層厚度及表面粗度控制。本研究乃以陰極電弧放電離子被覆技術在Inconel 600基材上被覆NI-Al鍍層，與目前常用的高速火焰融射CoCrAlY塗層同時進行1100 ℃高溫循環氧化試驗，比較二者的抗高溫循環氧化性。研究結果顯示：使用Ni52Al48、Ni60Al40及Ni70Al30三種靶材分別得到富鋁成份的Ni35Al65、Ni40Al60以及Ni53Al47的鍍膜在1100℃ 熱循環氧化測試下，由於富鋁的Ni-Al鍍膜表面能快速生成Al2O3層以阻止內部持續氧化，因而有較CoCrAlY塗層為低的氧化重量增加率。

Thermal Sprayed-YSZ/MCrAlY TBC systems are the currently used technology to the hightemperature enhancement of turbine blades and combustion chambers in nowadays turbine engines and power generation industries. Since the long service life of EB-PVD TBCs have been proved, and on the other hand, the CVD (Pt, Ni)Al bondcoat also have shown their higher hightemperature oxidation resistance and more adherent on substrate, the development of whole PVDYSZ/bondcoat in a single cycle coating run is attractive. A PVD process - Cathodic arc plasma ion plating was used to deposited Ni-Al films on Inconel 600 substrate. The oxidation behavior of PVD Ni-Al coating and the thermal sprayed CoCrAlY coatings were revealed and compared in 1100℃ cyclic thermal oxidation test. Experimental results show that films with different composition Ni62Al38, Ni63Al37 and Ni69Al31 could be obtained when using Ni52Al48, Ni60Al40 and Ni70Al30 target, respectively. During the 1100℃ cyclic thermal oxidation test, the aluminum-rich Ni-Al films were beneficial to form an Al2O3 layer on the surface and stop oxidation rapidly and caused the lower oxidation mass change than CoCrAlY coating.