Microstructure and Mechanical Properties of Low-Density, B2-Ordered AlNbZrTi<sub>x</sub> Multi-Principal Element Alloys

oleh: Qunhua Tang, Honghong Su, Shilong Peng, Wei Chen, Pinqiang Dai

Format: Article
Diterbitkan: MDPI AG 2022-05-01

Deskripsi

Low-density multi-principal element alloys (MPEAs) combining a high specific strength and considerable ductility have remained a research hotspot, due to their promising prospects for energy-saving industrial applications. Light Ti-containing AlNbZrTi<sub>x</sub> (x = 1−3) MPEAs were designed and prepared by induction melting and annealing. As the Ti content increases, the microstructure of these MPEAs evolves from dual phase (B2-ordered and Zr<sub>5</sub>Al<sub>3</sub>-type structure) into a single-phase B2-ordered structure, while the density reduces by ~8.7%, from ~5.85 g·cm<sup>−3</sup> (x = 1) to ~5.34 g·cm<sup>−3</sup> (x = 3). Unexpectedly, the AlNbZrTi<sub>x</sub> (x = 1, 2, 3) alloys possess high specific yield strengths of ~270 kPa·m<sup>3</sup>·kg<sup>−1</sup>, ~221 kPa·m<sup>3</sup>·kg<sup>−1</sup>, >208 kPa·m<sup>3</sup>·kg<sup>−1</sup>, along with excellent fracture strains of ~17.8%, 21.8%, and >50%, respectively. These combined compressive properties are superior to the reported data of most BCC/B2-dominant MPEAs. The deformation mechanism of the B2-ordered structure is explained as a dislocation-based mechanism, accompanied by antiphase domains. Here, the effect of Ti on the microstructure and compressive properties of AlNbZrTi<sub>x</sub> MPEAs was investigated, providing scientific support for the development of advanced low-density materials.