Metallurgical and Materials Transactions A

, Volume 39, Issue 7, pp 1496–1505

Low-Temperature Processing of ZrB2-ZrC Composites by Reactive Hot Pressing

Authors

  • Lingappa Rangaraj
    • Materials Science DivisionNational Aerospace Laboratories
  • Siriyara J. Suresha
    • Materials Research CentreIndian Institute of Science
  • Canchi Divakar
    • Materials Science DivisionNational Aerospace Laboratories
    • Department of Materials EngineeringIndian Institute of Science
Symposium: Materials Behavior: Far From Equilibrium

DOI: 10.1007/s11661-008-9500-y

Cite this article as:
Rangaraj, L., Suresha, S., Divakar, C. et al. Metall and Mat Trans A (2008) 39: 1496. doi:10.1007/s11661-008-9500-y

Abstract

Dense ZrB2-ZrC and ZrB2-ZrCx∼0.67 composites have been produced by reactive hot pressing (RHP) of stoichiometric and nonstoichiometric mixtures of Zr and B4C powders at 40 MPa and temperatures up to 1600 °C for 30 minutes. The role of Ni addition on reaction kinetics and densification of the composites has been studied. Composites of ∼97 pct relative density (RD) have been produced with the stoichiometric mixture at 1600 °C, while the composite with ∼99 pct RD has been obtained with excess Zr at 1200 °C, suggesting the formation of carbon deficient ZrCx that significantly aids densification by plastic flow and vacancy diffusion mechanism. Stoichiometric and nonstoichiometric composites have a hardness of ∼20 GPa. The grain sizes of ZrB2 and ZrCx∼0.67 are ∼0.6 and 0.4 μm, respectively, which are finer than those reported in the literature.

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2008