Effect of hot-pressing temperature on densification and mechanical properties of titanium diboride with silicon nitride as a sintering aid

The effect of hot-pressing temperature on the densification behavior and me chanical properties of titanium diboride (TiB2) was investigated. TIB2 spec imens were hot-pressed for 1 h at temperatures in the range of 1500 degrees -1800 degrees C, with an addition of 2.5 wt% of silicon nitride (Si3N4) as a sintering aid. The density increased markedly at temperatures in the rang e of 1500 degrees-1600 degrees C and remained constant thereafter. The form ation of a eutectic liquid at 1550 degrees C was attributed to the steep in crease in density. The hot-pressing temperature also improved the mechanica l properties, such as the flexural strength, Vickers hardness, and fracture toughness of the specimens. Similar to the density, the mechanical propert ies improved remarkably at similar to 1550 degrees C, so that optimum prope rties were obtainable at temperatures as low as 1600 degrees C.