摘要
用热重法研究了5种铸态TiAl在静止空气中的高温(700℃～1000℃)断续氧化行为。TiAl在700℃,100h氧化轻微。800℃,100h～1000℃,100h氧化动力学曲线可用幂函数ΔMn=knt描述,通常1<n<2。这表明,TiAl的断续氧化规律一般介于线性规律与抛物线规律之间。中、高温(≤900℃)氧化时,合金成份对TiAl的氧化行为影响显著,但随着氧化温度进一步增高,不同TiAl基合金间的氧化行为差别减小。高温或长时间氧化易导致外氧化层脱落,使氧化加快。一般地,低铬合金化TiAl的耐氧化性较差,而二元TiAl的耐氧化性较好。
The interrupted oxidation behaviours of five kinds of as cast TiAl alloys at 700℃~1 000℃ in static air have been investigated using thermogravimetric analysis (TGA). The results show that the oxidation of the TiAl alloys at 700℃ for 100 h is slight, and the interrupted oxidation kinetic curves of the TiAl alloys at 800℃~1 000℃ for 100 h can be described by a power function (Δ M n = k n t , where 1≤ n ≤2 normally), indicating that the interrupted oxidation curves of the TiAl alloys lie in between linear and parabolic ones. Alloying constituents of the TiAl alloys remarkably influence the oxidation behaviour at middle and high temperatures (for example 900℃), while the differences between the oxidation behaviours of the five TiAl based alloys studied become smaller as the oxidizing temperature increases further (for example up to 1 000℃). The oxidation resistance of binary TiAl alloys is better than that of ternary TiAl Cr alloys. The oxide layers spall off when TiAl alloys oxidize at high temperature or for long times, thereby causing the oxidation to accelerate.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2000年第1期8-12,共5页
Rare Metal Materials and Engineering
基金
国家重大自然科学基金!资助项目 (批准号 :5 9895 15 0 )
