Composites of NbC/ZrO₂ reinforced with different weight ratios of Cr metal were prepared by dynamic compaction combustion from a blend of Nb₂O₅-Zr-Cr powders. Factors controlling the synthesis process, the microstructure and the mechanical properties of the samples, such as Cr wt% and the compression loads were studied. The samples were characterized by XRD, SEM, porosity and hardness measurements. The porosity value of sample with no additives was high and reached 31.6 vol%. A sudden decrease in the sample porosity to 2.4 vol % was noticed for sample containing 3.0 wt% of Cr. A high density sample with less than 2.0 vol % porosity and a maximum hardness of 1038 HV was produced using 5.0 wt% Cr under 300 MPa compression load. Detailed thermodynamic calculations for the effect of Cr additives on the physico-chemical properties of the system were introduced.