Fabrication and thermophysical properties of porous TiB2 ceramics fabricated by reactive spark plasma sintering

• This is the first report on the fabrication of porous TiB2 ceramics.
• The porosity of porous TiB2 ceramics can be controlled readily.
• The thermophysical properties of porous TiB2 ceramics can be controlled.

Titanium oxide (TiO2) and boron carbide (B4C) were added to TiB2 raw powders to prepare porous TiB2 ceramics by reactive spark plasma sintering, and the gas escape (such as CO and B2O3) resulted in higher porosity. X-ray Diffraction results indicated that the reduction reaction was completed after the reactive spark plasma sintering process. The porosity could be controlled by changing the ratio of synthesized TiB2 to raw TiB2 powders. The porosity of porous TiB2 ceramics with 20 wt.% and 40 wt.% synthsized TiB2 ceramics are 18.5% and 22.2%, respectively. The thermal diffusivity of the porous TiB2 ceramics decreased with the porosity due to the low diffusivity behavior of gas and vacuum in pores, and the thermal conductivity for porous TiB2 ceramics decreased as the temperature increased throughout the measured temperature range. The results here pointed to a potential method for fabricating porous TiB2 ceramics with controllable thermophysical properties.