Microstructure, thermo-physical, mechanical and wear properties of in-situ formed boron carbide -Zirconium diboride composite

Research output: Contribution to journalArticlepeer-review

Authors

  • T. S.R.C. Murthy
  • Sairam Ankata
  • J. K. Sonber
  • K. Sairam
  • Kulwant Singh
  • And 5 others
  • A. Nagaraj
  • P. Sengupta
  • R. D. Bedse
  • Sanjib Majumdar
  • Vivekanand Kain

Colleges, School and Institutes

External organisations

  • Bhabha Atomic Research Centre
  • Homi Bhabha National Institute, Mumbai
  • Indian Institute of Technology, Kharagpur

Abstract

Microstructure, thermos-physical, mechanical and wear properties of in-situ formed B4C-ZrB2 composite were investigated. Coefficient of thermal expansion, thermal diffusivity and electrical resistivity of the composite were measured at different temperatures up to 1000°C in inert atmosphere. Flexural strength was measured up to 900°C in air. Friction and wear properties have been studied at different loads under reciprocative sliding, using a counter body (ball) of cemented tungsten carbide (WC-Co) at ambient conditions. X-ray diffraction (XRD) and electron probe microanalysis (EPMA) confirmed the formation of ZrB2 as the reaction product in the composite. Electrical resistivity was measured as 3.02 × 10-4 Ω·m at 1000°C. Thermal conductivity measured at temperatures between 25°C and 1000°C was in the range of 8 to 10 W·(m-K)-1. Flexural strength of the composite decreased with increase in temperature and reached a value of 92 MPa at 900°C. The average value of coefficient of friction (COF) was measured as 0.15 at 20 N load and 10 Hz frequency. Increase of load from 5 N to 20 N resulted in decrease in COF from 0.24 to 0.15 at 10 Hz frequency. Specific wear rate data observed was of the order of 10-5 mm3·(N-m)-1. Both abrasive and tribo-chemical reaction wear mechanisms were observed on the worn surface of flat and counter body materials. At higher loads (≥ 10 N) a tribo-chemical reaction wear mechanism was dominant.

Details

Original languageEnglish
Pages (from-to)15-30
Number of pages16
JournalCeramics - Silikaty
Volume62
Issue number1
Publication statusPublished - 1 Jan 2018

Keywords

  • Boron carbide, Electrical resistivity, Microstructure, Thermal conductivity, Wear resistance, XRD