Effects of HfB<sub>2</sub> Content and Microwave Sintering on the Mechanical Properties of Ti<sub>2</sub>AlC Composites.

Abstract

This study investigates the influence of the HfB₂ content and sintering method on the mechanical behavior of Ti₂AlC-based composites. Compositions containing 0-10 wt.% HfB₂ are processed via conventional and microwave sintering at 1200 °C for 30 min. X-ray diffraction and scanning electron microscopy analyses have confirmed the formation of the Ti₂AlC and HfB₂ phases, whereas the TiC phase is predominantly observed in samples processed by conventional sintering. The highest hardness (~475 HV) and compressive strength (~450 MPa) are that of the composite containing 5 wt.% HfB₂ associated with a porosity reduction of approximately 10%. These improvements are attributed to the enhanced densification and microstructural refinement achieved via microwave processing. The findings underscore the potential of HfB₂ addition and microwave sintering in tailoring the structure-property relationships of the Ti₂AlC composites, enabling applications at high-temperature filtration, thermal barriers, and self-lubricating components.