Pressure- and Additive-Mediated Sintering of B 4 C at Relatively Low Temperatures

A significant improvement in sinterability of B 4 C was achieved at a relatively low temperature by applying high pressure (2 GPa) and adding a small amount (5 wt pct) of Ni. The sintered B 4 C and Ni powder mixture showed improved hardness in the range of 21 to 32 GPa and improved modulus as compared to the sintered B 4 C powder without additive. This is mostly attributed to the formation of Ni 4 B 3 , as characterized by Reitveld refinement method and transmission electron microscopy (TEM), which enhances the bonding between B 4 C particles. These results provide a new avenue toward the development of sintering of B 4 C at relatively low temperatures (<0.5 T m of B 4 C).