Flash spark plasma sintering of pure TiB2

Flash Spark Plasma Sintering (FSPS) was used to rapidly sinter pure titanium diboride (TiB2). A pre-sintered sample (Ø= 20 mm with relative density 60%) was discharged under a current of 2-2.5 kA flowing entirely across the sample. The samples were locally densified up to 98% of relative density in a very short time of 20 seconds. The rapid heating (?6000 °C/min) prevented the complete evaporation of B2O3, leading to the formation of rarely seen segregation of boron at the grain boundaries. Compared to SPS or hot press, the rapid FSPS processing promoted the formation boron rich grain boundaries during sintering, thus enhancing consolidation. The FSPS approach might be suitable to consolidate other refractory borides.