Role of boron addition on the consolidation and properties of steel composites prepared by SPS

Composites reinforced with 8 vol% TiB2 were subjected to the consolidation process by spark plasma sintering (SPS). The results show that the addition of boron (1 vol%) introduced to the steel matrix has a significant effect on the composite microstructure, as well as physical, mechanical and tribological properties. The full density of 97–99% was obtained in the composites sintered at a temperature of 1100∘C. The steel–8% TiB2–1% B composite sintered at 1100∘C for 30 min was characterized by the highest microhardness (465 HV0.3) and Young’s modulus (229 GPa), combined with the best compressive strength (1150 MPa) and abrasive wear resistance (μ = 0.25 and W V(disc) = 207.78 × 10−6 mm3 N−1m−1). The microstructure and chemical composition were examined by scanning electron microscopy and transmission electron microscopy. The examinations have revealed the presence of numerous fine complex borides in the microstructure of the steel–8% TiB2 and steel–8% TiB2–1% B composites.