表面Ni及Ni-Al鍍層對Ti-6Al-4V合金抗高溫氧化之研究

Effects of Surface Platings by Ni and Ni-Al on High-Temperature Oxidation Behavior of Ti-6Al-4V Alloy

林哲綸(C. L. Lin) ； 汪瑞芳(R. F. Wang) ； 邱宗聖(T. S. Chiou) ； 開物(W. Kai) ； 李志偉(J. W. Lee)

《防蝕工程》 23卷3期 (2009/09) Pp. 203-211

https://doi.org/10.6376/JCCE.200909.0203

摘要

本研究主要探討商用鈦合金Ti-6Al-4V(Ti-64)在施以表面Ni及Ni-Al改質後，於700~900℃空氣條件下的高溫氧化行爲。其中，表面改質可分別爲單純電鍍Ni[Ti-64(Ni)]及電鍍鎳加滲Al[Ti-64(NA)]兩種。研究結果顯示，Ti-64(Ni)在700℃時仍遵守拋物線律，而在800~900℃呈現直線律，但Ti-64(Ni)在各溫度之氧化動力學皆遵守拋物線律。Ti-64(Ni)在700℃氧化主要生成NiO，此時鍍Ni層具有保護基材的作用；但當溫度上升至800~900℃時，氧化生成物則主要是TiO2，顯示鍍Ni層已失去保護作用。而Ti-64(NA)在700~800℃下生成保護性良好之降α-Al2O3氧化物，但在900℃條件下卻生成α-Al2O3及TiO2兩種混合氧化物。

關鍵字

氧化動力學 ； 氧化鎳 ； 氧化鋁 ； 氧化鈦

並列摘要

The effects of various Ni-Al surface modifications on the high temperature oxidation behavior of Ti-6A1-4V (Ti-64) alloy were studied over the temperature range of 700~900℃ in air. Two different Surface modifications were adopted in the study, including the pure electro-plating Ni [Ti-64(Ni)] and the pre-Ni plating followed by the aluminizing treatment [Ti-64(NA)]. The results showed that the oxidation kinetics of Ti-64(Ni) followed a parabolic rate law at 700℃, but linear kinetics were observed at 800~900℃. In addition, the oxidation kinetics of the Ti-64(NA) alloy followed a parabolic-rate law throughout the entire temperature range of interest.
The scales formed on the surface-modified Ti-64 alloys were strongly dependent on coating composition and temperature, consisting of an exclusive NiO at 700℃ for Ti-64(Ni), while an exclusive TiO2 was present at 800~900℃. On the other hand, the scales formed on the Ti-64(NA) consisted of an exclusive α-Al2O3 at 700~800℃, while both α-Al2O3 and TiO2 were detected at 900℃.

並列關鍵字

Oxidation kinetics ； NiO ； α-Al2O3 ； TiO2