Disorder trapping in Ni-3(Al, Ti) by solidification from the undercooled melt

被引：9

作者：

Goetzinger, R ^{[1
]}

Barth, M ^{[1
]}

Herlach, DM ^{[1
]}

Hunziker, O ^{[1
]}

Kurz, W ^{[1
]}

机构：

[1] ECOLE POLYTECH FED LAUSANNE, DEPT MAT, CH-1015 LAUSANNE, SWITZERLAND

来源：

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 1997年 / 226卷

关键词：

dendritic growth; disorder trapping; Ni3Al; Ni-Al-Ti;

D O I：

10.1016/S0921-5093(97)80052-4

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Modelling of rapid solidification predicts disorder trapping in the superlattice structure of Ni3Al. However, experimental investigations on this compound suffer from ambiguities concerning the solidification path. There is a phase selection competition between the ordered fcc gamma'-phase (Ni3Al), the ordered bcc beta-phase (NiAl), the disordered fcc gamma-phase (Ni), the stable gamma/beta eutectic and the metastable gamma/beta eutectic, and there are subsequent solid state transformations. A replacement of several at.% Al by Ti leads to a stabilization of the gamma'-phase and to an avoidance of most of the problems encountered on Ni3Al. The experiments on Nu(3)(Al, Ti) presented here clearly show the expected disordered crystallization from the undercooled melt. This was proven by measuring the dendrite growth velocity of electromagnetically levitated droplets and by analysing the data in the framework of dendrite and kinetic growth models. Complementary microstructural investigations were performed on the as-solidified samples. (C) 1997 Elsevier Science S.A.

引用

页码：415 / 419

页数：5

共 23 条

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