A comparative study of microstructure, compressive, and fracture properties of Ti3Al-based intermetallics produced via powder metallurgy, and melting and casting processes

Abstract

AbstractA comparative study of the microstructure, compressive properties, and fractography of Ti3Al and Ti3Al–Nb intermetallics produced via powder metallurgy and standard vacuum melting and casting processes has been carried out. Non-porous compacts were obtained via vacuum hot pressing of powders produced by mechanical alloying. Prior to compression tests, all samples were homogenized by a solution treatment at 1050°C (α + β region), followed by water quenching. The compression tests were performed from room temperature to 500°C in vacuum at a strain rate of 2.4 × 10–3s–1. Detailed microstructural characterization was conducted using scanning electron microscopy, followed by energy dispersive X-ray spectroscopy and X-ray diffraction analysis. Values of compressive mechanical properties of compacts were higher than those of castings. Fracture topography was examined by scanning electron microscopy. A correlation between ductility and the fracture mode exists for all materials.