Effect of TiB2 addition on the mechanical and biological response of spark plasma sintered Ti6Al7Nb matrix composites

In situ fabrication of TiB whiskers (TiB w ) reinforced Ti-matrix composites (TMCs) was carried out with the addition of TiB 2 particles in Ti6Al7Nb matrix using low energy ball milling and subsequent consolidation via Spark Plasma Sintering (SPS). The ball mixing of 0.5, 1.5, and 3% TiB 2 resulted in its distribution ratio (RD) of 1.05, 3.2, and 6.5, respectively. The in situ TiB w formations as a reaction between the Ti6Al7Nb matrix and TiB 2 particles resulted during sintering. This TiB w inclusion in different regions caused the retardation of grains from growing and resulted in grain refinement. The presence of a stiff TiB w phase in combination with grain refinement was ascribed to the increased hardness and higher strength in the fabricated composites. Maximum hardness (~ 496 Hv) and strength (~ 2233 MPa) was achieved in the 3% TiB 2 containing composites among all. The biological response showed better cell adhesion and proliferation without any toxic effect on all fabricated samples when compared to the wrought Ti6Al7Nb. The enhanced cell proliferation on the TiB w composites than the pure alloy demonstrates them as promising materials for biomedical applications. • The fine in situ TiB reinforcement as a result of TiB 2 addition was done for Ti6Al7Nb matrix composite fabrication. • Fine distribution of TiB provided microstructure refinement and strengthening of the composites. • The increase in mechanical properties and improved biological response was recorded with the increase in reinforcement content.