Determining the fracture resistance of B4C-NanoSiB6 nanocomposite by Vickers indentation method and exploring its mechanical properties

In this research, the effects of NanoSilicon hexaboride (NanoSiB6) additive, as a sintering aid, on mechanical properties and the sinterability of Boron Carbide (B4C) have been investigated. In addition, the results of several equations used for determining the Indentation fracture resistance (KIFR) by Vickers indentation test have been evaluated. For this purpose, 0, 2, 4, 6 and 8 wt% NanoSiB6 additive have been added to B4C in order to improve its sinterability at temperatures 2050, 2150 and 2250 °C. The findings indicate that by adding NanoSiB6, up to 4 wt%, to B4C, its properties such as relative density, Young's modulus, microhardness and KIFR improve as the sintering temperature rises; however, these properties diminish with the further increase of the mentioned sintering aid. Also, a comparison between KIFR values shows the closeness of the results obtained by different equations and the satisfactory accuracy of the equation for determining KIFR by crack area method compared to the results of other equations; with a difference of < 20% between the two results.