In-situ observation of Nb/Nb5Si3 two-phase alloys during bending at various temperatures

Seiji Miura, Yukiyoshi Tsutsumi, Tetsuo Mohri

Research output: Chapter in Book/Report/Conference proceedingConference contribution


In order to understand the deformation and fracture behavior of Nb-Si alloys, in-situ observation was conducted during bending of small specimens at room and high temperatures. Nb-Si alloy ingots containing 18.1 at.%Si, 1.5 at.%Zr and 100 ppmMg were prepared by arc melting, followed by uni-axial solidification in an optical floating zone apparatus and a heat-treatment to obtain Nb/Nb5Si3 two-phase microstructure. Chevron-notched specimens with a dimension of 1x2x10mm were used for in-situ observation of bending tests under a confocal laser scanning microscope (CLSM) at room temperature and at 1140°C. At room temperature the Nb-Si alloy shows a fracture toughness of 8 MPa m1/2 and the crack propagation velocity seems to be not uniform, presumably due to the ductile Nb. At 1140°C the toughness of the alloy was about 20 MPa m1/2 and slower plastic deformation prior to the cracking was observed. The SEM observation of crack surfaces revealed that plastic deformation of Nb enhances the toughness of the alloy.

Original languageEnglish
Title of host publicationIntermetallic-Based Alloys for Structural and Functional Applications
Number of pages6
Publication statusPublished - 2011
Event2010 MRS Fall Meeting - Boston, MA, United States
Duration: 2010 Nov 292010 Dec 3

Publication series

NameMaterials Research Society Symposium Proceedings
ISSN (Print)0272-9172


Other2010 MRS Fall Meeting
Country/TerritoryUnited States
CityBoston, MA

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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