Influence of SiAlON Ceramic Reinforcement on Ti6Al4V Alloy Matrix via Spark Plasma Sintering Technique

Abstract

The titanium-based composite was fabricated by strengthening Ti6Al4V alloy with addition of SiAlON ceramics utilizing spark plasma sintering technique. Ti6Al4V and SiAlON powders were mixed in a T2F Turbula mixer with different proportions (5, 10, 15 and 20 vol%) and the admixed powders were consolidated using spark plasma sintering to produce titanium matrix composites. The characterization of the sintered composites was performed using X-ray diffraction, optical microscopy and scanning electron microscopy. The influence of SiAlON additions on densification, microstructure, microhardness and fracture morphology were investigated on the sintered composites. The experimental results revealed that the densification of the sintered titanium matrix composites was in the range of 95%–98%, which decreased with an increase in SiAlON addition. However, an increase in microhardness values ranging from 363 to 574 HV0.1 was achieved. The microstructure shows that the SiAlON ceramic particle was uniformly distributed within the titanium matrix composites which comprises of a mixture of lamellar colonies with β grain boundaries. The fracture features of all composites exhibit mixed fracture of both intergranular and transgranular fracture mechanism.