A novel ZrB2-based composite manufactured with Ti3AlC2 additive

A novel ZrB2-Ti3AlC2 composite was densified using spark plasma sintering at 1900 degrees C under pressure of 30 MPa for 7 min. The effect of Ti3AlC2 MAX phase on the densification behavior, microstructural evolutions, phase arrangement, and mechanical properties of the composite were investigated. The phase analysis and micro-structural studies revealed the decomposition of the MAX phase at the initial steps of the SPS process. The structural characteristics and surface morphology of the in-situ synthesized reinforcements were verified using Xray diffraction and scanning electron microscopy, respectively. The formation mechanism of each reinforcement phase was also investigated using thermodynamical assessments. The prepared ZrB2-Ti3AlC2 composite not only possessed a near fully-dense characteristic having an excellent hardness of 31 GPa, but also unexpectedly presented high fracture toughness. The indentation fracture toughness of the composite was calculated as 7.8 MPa m(1/2), which is unprecedented compared with the same class of hard ZrB2-based composites. Indeed, the superior mechanical properties of the composite achieved in this study was obtained by the homogenous distribution of Al-based reinforcements, formation of hard interfacial ZrC grains, and solid solutions provided by Ti-based phases. The correlations between the phase arrangement, microstructure, and the attained mechanical properties of the composite were comprehensively discussed.

Automated summary

In this study, a novel ZrB2-Ti3AlC2 composite was successfully densified using spark plasma sintering, and the effect of Ti3AlC2 MAX phase on the composite's densification behavior, microstructural evolution, and mechanical properties was thoroughly investigated. The prepared composite exhibited a combination of high hardness and fracture toughness, attributed to the homogenous distribution of reinforcements and the formation of hard interfacial grains. The correlations between phase arrangement, microstructure, and mechanical properties were comprehensively discussed, providing insights into the superior mechanical properties achieved in this study.