Effect of TiB2 nano-inclusions on the thermoelectric properties of boron rich boron carbide. (2018)

• Record Type: Journal Article
• Authors: Ponnusamy, Prasanna; Feng, Bing; Martin, Hans-Peter; Groen, Pim
• Is Part Of: Materials today. Volume 5:Number 4(2018)Part 1
• Page Start: 10306
• Page End: 10315
• Publication Date: 2018
• Subjects: Boron-rich boron carbide -- BxC- TiB2 composite -- Thermoelectric properties -- Densification; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2017.12.278
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Boron carbide has exceptional thermoelectric properties due to its unique crystal structure. The effects of nano-TiB2 inclusions on the thermoelectric properties of boron rich boron carbide is presented here. Boron rich boron carbide-TiB2 composites were prepared in-situ by sintering of wet ball milled B, B4 C and nano-TiO2 powders through Spark Plasma Sintering (SPS) at 1900 °C under 50 MPa pressure. Five different compositions of the composite were prepared- with 1, 2.5, 5, 7.5 and 10 wt.% TiO2 . The dependence of densification and thermoelectric properties on TiO2 content were studied. The microstructure was observed through Field Emission Scanning Electron Microscope (FESEM) and phases were analyzed using X-ray diffraction (XRD). Relative densities of 94.8% to 99. 3% were obtained and an almost homogeneous distribution of TiB2 was observed. The electrical property was found to be high for sample with 1 wt% TiO2 and reduced subsequently with higher wt% of TiO2 . The overall dimensionless figure of merit was found to be higher than B4 C-TiB2 composites, due to the formation of boron rich phase but the effect of TiO2 was not significant. The increase in lattice parameter of boron carbide phase for different TiO2 amounts added showed that the final composition of the composite depends on the amount of TiO2 added.