ORDERED DOMAINS IN TIAL COEXISTING WITH TI3AL IN THE LAMELLAR STRUCTURE OF TI-RICH TIAL COMPOUNDS
ORDERED DOMAINS IN TIAL COEXISTING WITH TI3AL IN THE LAMELLAR STRUCTURE OF TI-RICH TIAL COMPOUNDS
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DOI：
10.1080/01418619208201574
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发表时间：
1992-10-01
期刊：
影响因子：
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通讯作者：
YAMAGUCHI, M
中科院分区：
文献类型：
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作者：
INUI, H;OH, MH;YAMAGUCHI, M
用透射电镜研究了富钛TiAl化合物层状结构中与Ti3Al相共存的TiAl相中有序畴的形貌、分布及其相对取向。（111）TiAl//(0001)Ti2Al和[110]TiAl//[1120]Ti3Al的取向关系决定了TiAl相中存在6种不同类型的有序畴。在所有类型的TiAl有序畴中，[110]方向与Ti3Al的[1120BAR]方向完全平行，而[011BAR]方向在（111）片层面上相对于Ti3Al的[1120BAR]方向旋转0.2 ~ 0.3度。TiAl有序畴不仅存在于TiAl片层边界上，而且存在于每个TiAl片层内。层状畴边界，即相邻的两个TiAl片层之间的边界，是平坦且平行于（111）TiAl和（0001）Ti3Al，而存在于每个TiAl片层内的畴边界对某些晶体平面没有任何偏好。所有五种可能的取向关系都发生在由层状畴边界分隔的两个相邻畴之间，而在TiAl片层的畴边界中，只有两种取向关系保持了（111）TiAl的堆叠顺序。
The morphology and distribution of ordered domains and their relative orientation in the TiAl phase coexisting with the Ti3Al phase in the lamellar structure of Ti-rich TiAl compounds have been studied by transmission electron microscopy. Six different types of ordered domain exist in the TiAl phase because of the orientation relationship between the TiAl and Ti3Al phases, (111)TiAl//(0001)Ti2Al and [110]TiAl//[1120]Ti3Al. The [110] direction in all the types of TiAl ordered domain is exactly parallel to the [1120BAR] direction of Ti3Al while [011BAR] directions are rotated by 0.2-0.3-degrees on the (111) lamellar planes with respect to the [1120BAR] direction of Ti3Al. The TiAl ordered domains exist not only across the lamellar boundaries but also within each of TiAl lamellae. The lamellar domain boundaries, that is the boundaries between the two neighbouring TiAl lamellae, are flat and parallel to both (111)TiAl and (0001)Ti3Al, while the domain boundaries existing within each of TiAl lamellae do not have any preference for certain crystallographic planes. All five possible orientation relationships have been found to occur between two neighbouring domains separated by the lamellar domain boundaries while only two orientation relationships in which the stacking sequence of (111)TiAl is maintained occur for the domain boundaries in TiAl lamellae.