本研究使用Ti-6Al-4V(Ti64)於720℃~820℃熱浸純鋁，探討熱浸機制及熱浸鋁塗層對Ti64高溫腐蝕之作用。結果顯示，熱浸鍍之TiAl₃層厚度不隨熱浸溫度與時間而有顯著變化。由於鈦與液態鋁形成TiAl₃後體積大幅縮小，因此TiAl₃層中的TiAl₃顆粒(晶粒)均為Al所包覆。當熱浸後之Ti64再升溫到高於鋁熔點以上，晶粒間Al(l)快速沿晶與Ti64底材反應，再因體積收縮而使鋁化層呈現多孔之形貌。此多孔鋁化層之形貌於單純高溫氧化環境，因TiAl₃有很好的抗氧化性，雖然是孔洞形貌，但仍僅有少量的氧化增重。但在Na₂SO₄-V₂O₅熱腐蝕，熔融腐蝕鹽沿孔洞滲入，快速破壞鋁化層侵蝕合金底材。若Ti64熱浸鋁後先於鋁熔點溫度以下持溫擴散，較緩慢的固體擴散以及較小的體積收縮，可以獲得較緻密的TiAl₃層，大幅提升Ti64的抗熱腐蝕性。

In this study, Ti-6Al-4V (Ti64) was hot-dip pure aluminum at 720℃~820℃ to explore the hot-dip mechanism and the effect of hot-dip aluminum coating on hot corrosion. The results show that the thickness of the TiAl₃ layer did not change significantly with the hot-dip temperature and time. Since the volume of TiAl₃ formed by titanium and liquid aluminum is greatly reduced, the TiAl₃ particles (grains) in the TiAl₃ layer are covered by Al. When the Ti64 after hot dipping heats up to above the melting point of aluminum, the Al(l) rapidly reacts along the grain with the Ti64 substrate, and the aluminized layer appears porous due to volume shrinkage. The morphology of this porous aluminized layer is a simple high-temperature oxidation environment. Although TiAl₃ forms with a porous morphology, there is still only a small amount of oxidation weight gain, sicnce TiAl₃ has good oxidation resistance. However, in Na₂SO₄-V₂O₅ hot corrosion, molten salt penetrates along the pores, which leads to a rapid destruction of the aluminized layer and corrosion of the alloy substrate. If Ti64 is hot-dip aluminum and then diffuses below the melting point of aluminum, the coating has a slower solid diffusion and smaller volume shrinkage, which leads to a more compact TiAl₃ layer and a improvement of thermal corrosion resistance of Ti64.