Synthesis and sintering of TiB2 nanoparticles

Abstract Titanium diboride nanoparticles were prepared from TTIP and boron oxide using a sol-gel method followed by mechano-chemical reduction in the presence of aluminum. Optimum weight ratio of B 2 O 3 :TTIP:2-propanol was 1:3:60. The XRD results revealed that mechano-chemical reduction of the zerogel by aluminum had led to the formation of TiB 2 and Al 2 O 3 phases after 15 hours of milling. The XRD results confirmed complete removal of Al 2 O 3 via leaching the milled sample in 10 M NaOH at 150 °C. SEM and TEM studies showed that the mean particle size of the synthesized TiB 2 is less than 30 nm. The densification experiments were carried out using hot pressing and pressureless sintering. The binderless densification of monolithic TiB 2 up to 92% theoretical density was achieved by hot pressing at 1700 °C for 2 h in vacuum. The hot pressed TiB 2 exhibits high Vickers hardness (25.9 GPa) and relative high fracture toughness (5.7 MPa.m 1/2 ). In the pressureless sintering route, a maximum density of 82.3% ρ th is achieved after sintering at 1900 °C for 2 h in vacuum.