Determination of mechanical and vibrational properties of the Sr (Zn1-xAlx)13 intermetallic compound

Detailed knowledge about physical and chemical properties of the SrZn13 intermetallic compound is of technological importance in the design and manufacture of Sr-modified Zn-base alloys. The main objective of this study was to further knowledge of the mechanical and vibrational properties of the Al-incorporated Sr (Zn1-xAlx)(13) compound. The Sr(Zn1-xAlx)(13) was synthesized by melting down zinc ingots (high purity > 99.98%) and 20 wt% Al-10Sr master alloy at 600 degrees C for 1 h. Microstructural analysis by X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed the presence of a phase with the NaZn13-type structure attributed to the solid solution Sr(Zn1-xAlx)(13). This compound showed a lower value of hardness (H) than that theoretically reported for the pure SrZn13 compound but maintained the quasi-isotropic properties. The ductile behavior of the Sr(Zn1-xAlx)(13) is enhanced by the Al incorporation, as was displayed by DFT calculations. Several Raman vibrational modes arising for the breaking symmetry in the Zn sub-lattice were observed, which were mainly ascribed to the Al incorporation. Also, Raman measurements indicated possible formation of vacancies in the structure, which could be responsible for reducing experimental mechanical properties. Finally, it was determined that Raman spectroscopy is sensitive to the study of alloyed NaZn13-type structure compounds.