摘要
研究了定向凝固NiAl-15Cr合金的显微组织和高温拉伸变形行为。结果表明:定向凝固Ni-25Al-15Cr合金由β-NiAl枝晶干、γ/γ＇枝晶间相和γ＇过渡层组成。合金在1123—1373 K、初始应变速率为1.67×10^(-4)—1.67×10^(-2) S^(-1)的条件下表现出超塑性变形行为。在1323 K和初始应变速率为8.35×10^(-3)s(-1)条件下获得的最大延伸率为280％,应变敏感指数m为0.22。通过变形过程中显微组织观察,对其超塑性变形行为的机理进行了初步的讨论。
The microstructure and deformation behavior of high temperature tension of a directionally solidified (DS) NiAl-15Cr alloy have been investigated. The results reveal that the microstructure consists of dendritic beta-NiAl phase, interdendritic gamma/gamma' phase and transient layer gamma' phase. The alloy shows superplastic behavior when it is deformed under the conditions of temperature range of 1123-1373 K and initial strain rate range of 1.67 x 10(-4) - 1.67 x 10(-2) s(-1). The maximum elongation of 280% with m=0.22 is obtained at 1323 K and an initial strain rate of 8.35 x 10(-3) s(-1). The superplastic mechanism for the alloy is also discussed by the observation of the microstructures evolution during the superplastic deformation process.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2004年第5期494-498,共5页
Acta Metallurgica Sinica
关键词
定向凝固
NiAl基金属间化合物
超塑性
directional solidification
NiAl-based intermetallics
superplasticity
