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论文类型：期刊论文

发表时间：2013-01-01

发表刊物：Metallography, Microstructure, and Analysis

收录刊物：EI、Scopus

卷号：2

期号：3

页面范围：183-189

ISSN号：21929262

摘要：This article presents columnar grain structures characteristic of niobium components fabricated by electron beam melting, using two different size and size distribution spherical powders produced by rapid solidification atomization. The precursor powder microstructures are characterized by equiaxed grains while the columnar grain structure in the electron beam melted (EBM)-fabricated products contain dislocation substructures ranging in density from ~109 to 1010/cm2 as observed by transmission electron microscopy. X-ray diffraction analysis illustrates the variations in orientations in both the processor powders and the fabricated components. Microindentation hardness values ranged from 0.8 GPa for the precursor powders and 1.1 and 0.92 GPa for the EBM-fabricated, solid components. ? 2013 Springer Science+Business Media New York and ASM International.