摘要
Ni-32Al-28Cr-3Mo-4Ti(原子分数,％)共晶合金组织由β-NiAl和α-Cr(Mo)共晶组成,并含有少量初生β-NiAl相和Ni_2AlTi相．合金压缩屈服强度超过稀土Dy合金化的NiAl-Cr(Mo)合金,与NiAl-28Cr-5Mo-1Hf合金相当,表明Ti合金化有利于提高NiAl-Cr(Mo)共晶合金的强度．合金在1000℃下的蠕变断裂寿命和最小蠕变速率均与施加载荷之间呈线性的双对数关系,蠕变断裂寿命与最小蠕变速率之间满足Monkman-Grant关系修正式：t_f·((?)min)^(0.71)=0．51．合金的室温断裂方式为共晶相的解理断裂以及NiAl与Cr(Mo)相界面的剥离,高温蠕变断裂由共晶胞界处微空洞形成和聚集所导致．
The as-cast Ni-32Al-28Cr-3Mo-4Ti （atom fraction, %） eutectic alloy consists of β- NiAl and α-Cr（Mo） eutectic, as well as a small amount of primary β-NiAl and Ni2AlTi. Its compressive yield strength surpassed the Dy-doped NiAl-Cr（Mo） eutectic alloy, and is comparable to NiAl-28Cr- 5Mo-lHf eutectic alloy, indicating the addition of Ti is benefit to strengthening the NiAl-Cr（Mo） eutectic alloy. Both of the creep rupture life and minimum creep rate at 1000℃ vs applied stress fit linear dual-logarithmic relationship. The relationship between creep rupture life and minimum creep rate follows the modified Monkman-Grant equation： tf ·（εmin）^0.71 ： 0.51. The fracture mechanism at room temperature is cleavage fracture of NiAl and Cr（Mo） eutectic phases as well as separation of NiAl/Cr（Mo） interface, while the formation and aggregation of microvoids on eutectic boundaries leads to creep fracture.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第10期1031-1035,共5页
Acta Metallurgica Sinica
