研究了Ni-32Al-28Cr-3Mo-4Ti共晶合金的显微组织和力学性能. 合金组织由NiAl和Cr(Mo)相构成共晶形态, 并含有少量初生NiAl相和Ni2AlTi相. NiAl-Cr(Mo)-Ti共晶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. 合金的室温断裂方式为NiAl和Cr(Mo)共晶相的解理断裂以及NiAl/Cr(Mo)相界面的剥离, 高温蠕变断裂是由共晶胞界处微空洞形成和聚集导致的.
Microstructure and mechanical properties of a cast Ni-32Al-28Cr-3Mo-4Ti eutectic alloy have been investigated. The results show that the alloy consists of NiAl and Cr(Mo) eutectic zone, as well as a small amount of primary NiAl and Ni2AlTi. Its compressive yield strength surpasses Dy-doped NiAl-Cr(Mo) eutectic alloy, and is comparable to NiAl-28Cr-5Mo-1Hf eutectic alloy, indicating the addition of Ti is benefit to the strength of NiAl-Cr(Mo) eutectic alloy. Similar to the relationship between minimum creep rate and applied stress, the creep rupture life at 1000℃ vs. applied stress fits linear dual-logarithmic relationship. Modified Monkman-Grant equation can be used to describe the relationship between creep rupture life and minimum creep rate. The fracture mechanism at room temperature is cleaving of NiAl and Cr(Mo) eutectic phases as well as stripping of NiAl/Cr(Mo) interface, while the formation and aggregation of microvoids on eutectic boundaries leads to crept fracture.
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| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] |
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