Solidification characteristics of high Nb-containing γ-TiAl-based alloys with different aluminum contents
Solidification characteristics of high Nb-containing γ-TiAl-based alloys with different aluminum contents
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DOI：
10.1007/s12598-014-0416-y
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发表时间：
2015-06
期刊：
影响因子：
8.8
通讯作者：
Yi Liu;R. Hu;H. Kou;Jun Wang;Tie-Bang Zhang;Jinshan Li;Ji Zhang
中科院分区：
文献类型：
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作者：
Yi Liu;R. Hu;H. Kou;Jun Wang;Tie-Bang Zhang;Jinshan Li;Ji Zhang
采用x射线衍射仪（XRD）、能谱扫描电镜（SEM）和透射电镜（TEM）研究了Al含量对铸态和等温处理态Ti-Al-Nb-V-Cr合金显微组织和凝固特性的影响。典型的凝固特性是结晶温度范围和凝固路径共同影响的结果。较宽的结晶温度范围有利于铸态Ti47Al7Nb2.5V1.0Cr （at%）合金通过包晶反应凝固得到粗枝晶。β-凝固Ti46Al7Nb2.5V1.0Cr （at%）合金结晶温度范围窄，形成均匀的细晶组织。而Ti48Al7Nb2.5V1.0Cr （at%）合金的结晶温度范围与Ti46Al7Nb2.5V1.0Cr合金相当，但通过包晶反应凝固，形成更细的枝晶。
The effect of Al content on the microstructure and solidification characteristics of Ti–Al–Nb–V–Cr alloys in as-cast and isothermally treated states was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive spectroscope (EDS), and transmission electron microscopy (TEM). The typical solidification characteristics are due to the joint influence of both the crystal temperature range and the solidification path. The wide crystallization temperature range contributes to obtaining coarse dendrites in the as-cast Ti47Al7Nb2.5V1.0Cr (at%) alloy solidifying through the peritectic reaction. The β-solidifying Ti46Al7Nb2.5V1.0Cr (at%) alloy with the narrow crystallization temperature range is attributed to the formation of a homogeneous fine-grained microstructure. However, the crystallization temperature range of Ti48Al7Nb2.5V1.0Cr (at%) alloy is equivalent to that of Ti46Al7Nb2.5V1.0Cr alloy, but it is solidified by peritectic reaction, leading to the formation of finer dendrites.