J. Mater. Sci. Technol. ›› 2015, Vol. 31 ›› Issue (1): 91-96.DOI: 10.1016/j.jmst.2014.09.006

• Orginal Article • Previous Articles     Next Articles

Approach to the Theoretical Strength of Ti-Ni-Cu Alloy Nanocrystals by Grain Boundary Design

Alexandr M. Glezer1, 2, 3, *, Nadezhda A. Shurygina1, 2, Elena N. Blinova1, Inga E. Permyakova1, 2, Sergey A. Firstov4   

  1. 1 Bardin Central Research Institute for the Iron and Steel Industry, Vtoraya Baumanskaya ul. 9/23, Moscow 105005, Russia; 2 Moscow State University of Instrumental Engineering and Information Science (MGUPI), Moscow 107996, Russia; 3 National University of Science and Technology (MISIS), Moscow 119049, Russia; 4 Frantsevich Institute of Materials Science Problems, National Academy of Sciences of Ukraine, ul. Krzhizhanovskogo 3, Kiev 03680, Ukraine
  • Received:2014-03-21 Online:2015-01-20 Published:2015-07-23
  • Contact: * Corresponding author. Prof., Ph.D.; Tel./Fax: +7 495 777 93 50; E-mailaddress: a.glezer@mail.ru (A.M. Glezer).
  • Supported by:
    We thank A.V. Shelyakov for the amorphous alloys and S.S. Useinov for his help in performing depth sensing nanoindentation. This work was supported by the Russian Foundation for Basic Research (project Nos. 13-02-12087 and 14-02-31284).

Abstract: The grain boundary design was used to introduce boride Ti2B and TiB2 nanoparticles of 5 nm in size into grain boundaries of nanocrystalline Ti50Ni25Cu25 alloy. As a result, the maximum normalized microhardness was increased by 20% and the theoretical limit of hardness is substantially approached. It is proposed that boride nanoparticles suppressed low-temperature grain-boundary sliding and, therefore, shifted the range of the anomalous behavior of Hall-Petch relation toward smaller sizes of the Ti-Ni-Cu nanocrystals.

Key words: Electron microscopy, Microhardness, Nanocrystal, Nanoparticle, Grain boundary sliding, Theoretical hardness