Ni2TiAl介金屬在800~1200℃的高溫氧化行為研究

Study on Air Oxidation of Ni2TiAl at 800~1200℃

本研究主要探討Ni2TiAl介金屬合金在800 ~ 1200℃空氣下之高溫氧化行為特性，其結果並與Ni3Al及NiAl合金相互比較。結果顯示，三種合金的氧化動力學皆遵守拋物線律，其氧化速率隨著溫度上升而加快。Ni2TiAl合金在800℃時生成單一氧化層,包括TiO2、NiTiO3、Al2TiO5及Al2O3，並在其下有α-Ni層，而1000 ~ 1200℃生成兩層不同的氧化層，其外層主要的氧化物為NiO、TiO2、NiTiO3及NiAl2O4，而內層主要生成TiO2、NiTiO3、NiAl2O4、α-Al2O3及未氧化的α-Ni。

The oxidation behavior of Ni2TiAl intermetallic compound was studied at 800 ~ 1200℃ in dry air. The oxidation kinetics of the alloy followed the parabolic rate law at all temperatures, with its oxidation rate constants increased with increasing temperature. The scales formed on the Ni2TiAl alloy at 800℃ consisted of TiO2, NiTiO3, Al2TiO5 and Al2O3, and an α-Ni layer was observed beneath the scales. Double scales formed on the alloy at 1000 ~ 1200℃ , consisted mostly of NiO, TiO2, NiTiO3 and NiAl2O4 in the outer layer, and the scales formed in the inner layer consisted of TiO2, NiTiO3, NiAl2O4, Al2O3 and α-Ni.