Tough ceramics by microwave sintering of nanocrystalline titanium diboride ceramics

Dense composites of TiB2 with additions of TiN have been produced by microwave sintering. Microwave sintering was conducted at 1200-1700 degrees C under controlled atmosphere. The effects of composition, sintering temperature, on densification, microstructure, and mechanical properties were investigated. Microwave sintering resulted in uniform crack-free uniforrn microstructure, as well as maximum relative density of 99% and bending strength of 368 +/- 15 MPa, Young's modulus of 440 +/- 11 GPa, electric resistivity of 2 x 10(-5) Omega cm, Vickers hardness of 26.2 +/- 0.4 GPa, and a fracture toughness of 6.2 +/- 0.34 MPa.m(1/2) were obtained using 36 wt% TiB2, and sintering for 10 min at 1650 degrees C. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.