On the ω phase formation in Cr-Al and Ti-Al-Cr alloys
On the ω phase formation in Cr-Al and Ti-Al-Cr alloys
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DOI：
10.1016/s1359-6454(00)00168-3
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发表时间：
2000-09-04
期刊：
影响因子：
9.4
通讯作者：
Tsakiropoulos, P
中科院分区：
文献类型：
--
作者：
Shao, G;Tsakiropoulos, P
研究了Al与过渡金属钛、铬的相互作用对亚稳β结构中omega相稳定性的影响。合金从熔体中淬火，以在室温下保留在高温下稳定的亚稳β相(B2结构)。通过将w结构与理想w相的偏离与母体β相的组成进行关联，对w相的结构进行了研究。W结构偏离理想结构与母体β相的电子浓度有关。首次报道了Cr2Al相(C11(B)结构)中的弥散omega结构。结果与我们以前提出的Al通过降低母体β相中的空间传导电子浓度和加强价电子的Pd杂化来稳定过渡金属中的w相的观点一致。在Ti-Al-Cr三元合金中，对Ti-30Al-10Cr和Ti-20Al-10Cr合金进行450℃长时间的退火处理，形成了两种有序的晶态omega结构。(C)2000 Acta Metallurica Inc.由爱思唯尔科学有限公司出版。保留所有权利。
The interaction between Al and the transition metals Ti and Cr on the stability of the omega phase in metastable beta-based structures was studied. Alloys were quenched from the melt to retain at room temperature a metastable beta phase (B2 structure), which is stable at high temperatures. The structural study of the w phase was carried out by correlating the deviation of w structure from the ideal w phase to the compositions of the parent beta phase. Deviation of w structures from the ideal one was related to the electron concentration of the parent beta phase. A diffuse omega structure is reported in the Cr2Al phase (C11(b) structure) for the first time. The results are consistent with our previous suggestions that Al stabilises the w phase in transition metals by lowering the spatial conduction electron concentration in the parent beta phase and by enhancing pd hybridisation of valence electrons. In the ternary Ti-Al-Cr alloys, prolonged annealing of the Ti-30Al-10Cr and Ti-20Al-10Cr alloys at 450 degrees C led to the formation of two types of ordered crystalline omega structure. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.