Oxidation behavior of Zr-containing Ti_2AlNb-based alloy at 800°C  

含锆Ti_2AlNb基合金在800°C的高温氧化行为（英文）

作　　者：党薇[1] 李金山[1] 张铁邦[1] 寇宏超[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第3期783-790,共8页中国有色金属学报（英文版）

基　　金：Project(2011CB605503)supported by the National Basic Research Program of China

摘　　要：The oxidation behavior of Ti?22Al?(27?x)Nb?xZr (x=0, 1, 6) alloys at 800 °C for exposure time up to 100 h was examined. It is shown that oxidation rate of experimental alloys obeys the parabolic kinetics. Ti?22Al?26Nb?1Zr alloy demonstrates more excellent oxidation resistance than the other two alloys. The main oxidation products are TiO2, Al2O3 and AlNbO4 phases for all these alloys. For the Ti?22Al?26Nb?1Zr alloy, Zr addition can modify the growth mechanism of oxide scale, which can effectively hinder the diffusion of oxygen. Whereas, reaction of Zr with oxygen leads to the formation of ZrO2 precipitates for the Ti?22Al?21Nb?6Zr alloy, which promotes the oxygen ingress into the substrate. Meanwhile, oxidation affected zones, including internal-oxidation layer and oxygen-enriched zone, are present beneath the outmost oxide scale. The difference in these zones is derived from the phase constitution in the starting Ti?22Al?(27?x)Nb?xZr (x=0, 1, 6) alloys.研究Ti-22Al(27-x)Nb-xZr(x=0,1,6)合金在800℃暴露时间长达100 h条件下的氧化行为。结果表明,合金氧化速率符合抛物线规律。Ti-22Al-26Nb-1Zr合金的氧化性能优于其他两种合金。这些合金的氧化产物主要有TiO_2、Al_2O_3和AlNbO_4。对于Ti-22Al-26Nb-1Zr合金,Zr的添加可以改善氧化层的生长过程,从而有效阻止氧的扩散。然而,对于Ti-22Al-21Nb-6Zr合金,Zr与氧发生反应,形成ZrO_2,ZrO_2促使氧向合金基体内部扩散。同时,在氧化层下,存在包括内氧化层和富氧层的氧影响区域。不同合金氧影响区的差异主要归因于合金的初始相结构。

关 键 词：oxidation behavior Ti2AlNb-based alloy ZR oxide scale oxidation affected zone 

分 类 号：TG146.23[一般工业技术—材料科学与工程]