Micro-to-nano-scale deformation mechanism of a Ti-based dendritic-ultrafine eutectic alloy exhibiting large tensile ductility

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• 作者：I.V. Okulov^a ; ^b ; ^c ; ^{okulovilya@yandex.ru} ; M. Bö ; nisch^a ; ^d ; A.S. Volegov^a ; ^e ; H. Shakur Shahabi^a ; ^b ; H. Wendrock^a ; T. Gemming^a ; J. Eckert^f ; ^g
• 关键词：Titanium alloy ; TiCo intermetallic ; Ultrafine eutectic ; Fracture behavior ; Deformation mechanism ; Plasticity
• 刊名：Materials Science and Engineering: A
• 出版年：2017
• 出版时间：13 January 2017
• 年：2017
• 卷：682
• 期：Complete
• 页码：673-678
• 全文大小：3686 K
• 卷排序：682

文摘

Deformation mechanism of a new Ti-16.6Nb-6Co-5.1Cu-6.5Al (at%) alloy is studied using scanning and transmission electron microscopy. The alloy consists of micrometer-sized β-Ti dendrites and an ultrafine-eutectic composed of β-Ti and TiCo phases. The yield strength of the alloy (1.1 GPa) is comparable to that of the metallic glass composites and is coupled with large tensile ductility of about 11%. Transmission electron microscopy analysis reveals that slip lines formed during deformation in the dendrites penetrates the eutectic resulting in formation of a stepped interface and an extra area serving to accommodate shear strains. The β-Ti eutectic component can deform plastically to a high degree supporting deformation of TiCo. The results suggest that microstructural design of the eutectic is important for controlling tensile ductility of dendritic-ultrafine eutectic alloys.