鎳鋁介金屬如所周知為一高溫材料，可考慮做為抗氧化介層O如將其被覆在碳鋼或不錯鋼材表面並評估其氧化循環特性，將有助於日後應用於實際環境之參考。而近日更有利用陰極電弧放電離子被覆法製作MCrAIY介層，其性質優於傳統製程的報導。故本研究分別將鎳鋁介金屬被覆於探鋼及不錯鋼，利用熱福環氧化試驗，探討其抗循環氧化特性。並使用掃描式電子顯微鏡(Scanningelectron microscope， SEM)觀察試片熱循環前後的表面形態，輔以能量分散式元 素分析儀(Energydispersive spectrometer， EDS)分析試片表面元素， X-光繞射儀(X-ray diffractometer， XRD)鑑定熱循環前後試片的氧化層晶體結構，輝光放電激發光譜分析儀(Glow discharge optical emission spectrometer， GDOES)分析熱循環前後試片表面元素組成及其縱深分 佈狀況。

實驗結果顯示:鎳鋁介金屬可成功地被覆在碳鋼和不錯鋼表面，初沉積鍍膜中的主相為NiAl3。熱循環氧化試驗顯示鎳鋁鍍層可以有效保護鋼材。在碳鋼的保護機制為鍍層本身或其 生成的氧化鋁層阻擋氧擴散為主，兼而有鋁擴散使表面鏡層不易脫落所致。在不錯鋼的保護行為方面，saaoc熱循環時出現NiAl3相轉變成NiAI '且在鍍膜開放性孔洞的基材表面生成氧化鋁。的aoc熱循環時，微量鋁或鎳的擴散作用及生成的氧化層使氧化皮膜不易脫落，達到保護基材的效果。

Nickel-aluminide intermetallic compounds are known to be promising candidate for the bond coat materials. The cyclic oxidation behaviour can be used as a guide to suitability for applications in practical environments. Recent studies indicate that MCrAIY bond coats produced by cathodic arc plasma deposition are superior to those deposited by conventional Coating processes. This has motivated the present study on the cyclic oxidation resistance of nickel-aluminide coatings deposited on carbon steel and stainless steel using a cathodic arc plasma process. The deposited specimens and cyclic oxidtion tested specimens were examined by analytical instruments. Scanning electron microscope and the energy dispersive spectrometer were used to explore surface morphology and elemental composition. X-ray diffractometer was used to characterize crystal structure. Glow discharge optical emission spectrometer was used to probe composition depth profile.

Our results show that nickel-aluminide films can be successfully deposited on carbon steel and stainless steel substrates by this process. NiAl3 is the major phase in the deposited films. The cyclic oxidation behaviour suggests that such coatings can resist oxidation through physical blocking of oxygen， either by the coating itself or the subsequently formed aluminum oxide. The aluminum can also be beneficial to the iron oxide adhesion by the action of aluminum diffusion. The coating protects stainless steel at 500°C by transforming the NiAl3 phase into NiAI， producing aluminum oxide on the substrate surface nearby open pores of the coated film. At 800°C， oxide flaking is suppressed by the trace amounts of nickel or aluminum which have partially diffused into the substrate.