Thermoelectric and Mechanical Properties of SiC+SWCNTs+B4C Nanocomposites with Sol-gels Diffusion

Document Type

Conference Proceeding

Publication Date


Publication Title

2013 ASME District-F Early Career Technical Conference Proceedings, ASME ECTC


Thermoelectric (TE) and mechanical properties of Single wall carbon nanotubes (SWCNTs) and Boron Carbide reinforced Silicon carbide (SiC) nanocomposites were experimentally evaluated after doping through the sol-gel diffusion technique. The samples were produced with a high temperature (1550o C) sintering process. For sol-gel diffusion, a Boron-Antimony combination was used. Boron (B) was a Ptype and Antimony (Sb) was an N-type dopant. Hot and cold junctions were created using silver epoxy and Alumel (Ni-Al) wire, and thermoelectric tests were conducted. The carbon nanotubes used were approximately 60% semiconducting and 40% metallic. Voltage (mV) was measured for different categories of samples against temperature difference (∆T). Control SiC samples showed no TE effect at pristine form, but when infused with SWCNTs, a TE effect was present. The TE effect of the nanocomposite samples increased substantially with Boron-Antimony sol-gel diffusion. The Seebeck coefficient increased to 1.2 mV/ oC. Three point bending tests of the nanocomposites samples showed an interesting plateau in the flexure stress-strain curves. The structure-property relation was analyzed using SEM (scanning electron microscope) and EDS (Energy dispersive spectroscopy). It was revealed that fiber-like SWCNTs created a randomly distributed network, and Nano bridges inside the SiC matrix and enhanced the thermoelectric and mechanical properties of the nanocomposites.

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