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.
Original language | English |
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Pages (from-to) | 15-30 |
Number of pages | 16 |
Journal | Ceramics - Silikaty |
Volume | 62 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jan 2018 |
Keywords
- Boron carbide
- Electrical resistivity
- Microstructure
- Thermal conductivity
- Wear resistance
- XRD
ASJC Scopus subject areas
- Analytical Chemistry
- Ceramics and Composites
- Chemical Engineering(all)
- Physical and Theoretical Chemistry
- Materials Chemistry