商用鈦合金在不同氧分壓下之高溫氧化行為研究

High-Temperature Oxidation Behavior of Commercial Ti-Based Alloys at Various Oxygen Pressures

本研究主要在探討不同氧分壓（0.01 ~ 1 atm）對兩種商用鈦合金Ti-64（含Ti-6Al-4V）及SP-700（含Ti-4.5Al-3V-2Mo-2Fe）在700 ~ 900℃間的氧化行為。整體而言，兩種鈦合金的氧化動力學遵守抛物線律，且氧化速率皆隨溫度的上升而加快，但合金之氧化速率在氧分壓增加時呈現不規則變化，顯示合金氧化後的氧化生成物呈現N-型半導體的特徵。兩種合金氧化後主要生成TiO2，並有少量Al2O3生成。

The oxidation behavior of Ti-64 and SP-700 alloys was studied over the temperature range of 700 ~ 900 ℃ in various oxygen-containing atmospheres (at Po2 = 0.01 ~ 1 atm). The oxidation kinetics of the two alloys followed the parabolic rate law in all cases. The oxidation rates of the alloys gradually increased with temperature but were independent of oxygen partial pressure, indicating that the scaling of the two alloys possessed an n-type semiconductivity. The scales formed on the alloys consisted mostly of TiO2 and minor amounts of Al2O3, regardless of the oxygen pressure.