The effect of heating rate and composition on the properties of spark plasma sintered zirconium diboride based composites

Five different compositions of ZrB2–SiC–ZrC were prepared and then processed by spark plasma sintering (SPS) to a maximum temperature of 2000 °C, with heating rates of 100 °C/min and 200 °C/min. Grain size, density, Rockwell hardness, flexural strength, and thermal conductivity were evaluated for the processed composites. Adding SiC up to 10 wt.% had a positive effect on densification and strength. Increasing the heating rate promoted densification and less overall grain growth for samples with SiC and ZrC above 15 wt.% each, and had a slight negative effect on densification when these values were at 10%.

► We investigated the effect of heating rate on spark plasma sintering of ZrB2–SiC–ZrC composites. ► Adding SiC up to 10 wt.% had a positive effect on densification and strength. ► Increasing heating rate promoted densification and retarded grain growth when SiC and ZrC content was above 15 wt.%, respectively. ► Increasing heating rate had a slight negative effect on densification when SiC and ZrC content was at 10%, respectively.