Electrical and thermophysical properties of ZrB2 and HfB2 based composites

Mallik, Manab and Kailath, A J and Ray, K K and Mitra, R (2012) Electrical and thermophysical properties of ZrB2 and HfB2 based composites. Journal of the European Ceramic Society, 32 (10). pp. 2545-2555.

Restricted to NML users only. Others may use ->



Electrical resistivities, thermal conductivities and thermal expansion coefficients of hot-pressed ZrB2-SiC, ZrB2-SiC-Si3N4, ZrB2-ZrC-SiC-Si3N4 and HfB2-SiC composites have been evaluated. Effects of Si3N4 and ZrC additions on electrical and thermophysical properties of ZrB2-SiC composite have been investigated. Further, properties of ZrB2-SiC and HfB2-SiC composites have been compared. Electrical resistivities (at 25 degrees C), thermal conductivities (between 25 and 1300 degrees C) and thermal expansion coefficients (over 25-1000 degrees C) have been determined by four-probe method, laser flash method and thermo-mechanical analyzer, respectively. Experimental results have shown reasonable agreement with theoretical predictions. Electrical resistivities of ZrB2-based composites are lower than that of HfB2-SiC composite. Thermal conductivity of ZrB2 increases with addition of SiC, while it decreases on ZrC addition, which is explained considering relative contributions of electrons and phonons to thermal transport. As expected, thermal expansion coefficient of each composite is reduced by SiC additions in 25-200 degrees C range, while it exceeds theoretical values at higher temperatures.

Item Type:Article
Official URL/DOI:http://www.sciencedirect.com/science/article/pii/S...
Uncontrolled Keywords:Composites; Thermal conductivity; Thermal expansion; Electrical conductivity; Borides
Divisions:Material Science and Technology
ID Code:5631
Deposited By:Dr. A K Sahu
Deposited On:29 Jun 2012 10:15
Last Modified:29 Jun 2012 10:15
Related URLs:

Repository Staff Only: item control page