Sintering Mechanism, Microstructure Evolution, and Mechanical Properties of Ti-Added Mo₂FeB₂-Based Cermets

Four series of Mo₂FeB₂-based cermets with Ti contents between 0 wt.% and 1.5 wt.% in 0.5 wt.% increments were prepared by in situ reaction and liquid phase sintering technology. Influences of Ti on microstructure and mechanical properties of cermets were studied. It was found that Ti addition increases formation temperatures of liquid phases in liquid-phase stage. Ti atoms replace a fraction of Mo atoms in Mo₂FeB₂ and the solution of Ti atoms causes the Mo₂FeB₂ crystal to be equiaxed. In addition, the cermets with 1.0 wt.% Ti content exhibit the smallest particle size. The solution of Ti atoms in Mo₂FeB₂ promotes the transformation of Mo₂FeB₂ particles from elongated shape to equiaxed shape. With Ti content increasing from 0 wt.% to 1.5 wt.%, the hardness and transverse rupture strength (TRS) first increase and then decrease. The maximum hardness and TRS occur with 1.0 wt.% Ti content. However, the fracture toughness decreases as Ti content increases. The cermets with 1.0 wt.% Ti content show excellent comprehensive mechanical properties, and the hardness, fracture toughness, and TRS are HRA 89.5, 12.9 MPa∙m^1/2, and 1612.6 MPa, respectively.