Ta-7.5%W合金箔材的冷轧变形织构与微观结构

The Microstructures and Textures of the Cold-rolled Ta-7.5%W Alloy Foils

研究了140μm的Ta-7.5%W合金箔材在冷轧变形前后的织构和微观组织.结果表明:冷轧态和退火态的Ta-7.5%W合金箔材中主要形成了{001}<110>、{113}<110>、{112}<110>、{111}<110>四种织构组分;在冷轧的Ta-7.5%W合金箔材中,合金的{110}<110>取向和{113}<110>取向的晶粒中都形成了位错胞结构,且在{100}<110>方向上主要为大的等轴状位错胞结构,位错胞的平均大小在500 nm左右,而在{111}<110>取向形成了微带组织,这些微带互相平行,微带之间的平均间距在200 nm左右;微带主要由GNBs(geometrically necessary boundaries.几何必须位错界面)和IDBs(incidentaldislocation boundaries,附生位错界面)两种位错界面结构组成,GNBs中含有一组相互平行的高密度位错,位错之间的间距在5 nm左右。

The microstructure and texture in both the annealing and cold-rolled conditions of 140μm Ta-7.5%W alloy foils were investigated by TEM and orientation distribution function（ODF） analysis.It is found that the main texture components of the annealing and cold-rolled Ta-7.5%W alloys are {001}110,{113}110,{112}110 and {111}110.In the cold-rolled Ta-7.5%W alloy foils,the dislocation cell structures were formed in both {001}110 and {113}110 orientations.There were a lot of equiaxed cell structures with an average size of 500 nm in the grains of {001}110 texture.The microband structures were developed in the {111}110 grains,which are distributed parallelly in the grains with a mean space length of 200 nm.The microbands consist of GNBs and IDBs.In the GNBs,there were a set of high density parallel dislocations with the spacing of about 5 nm.