Nanoindentation studies on amorphous, nanoquasicrystalline and nanocrystalline Zr <inf>80</inf>Pt <inf>20</inf> and Zr <inf>75</inf>Pd <inf>25</inf> alloys

Nanoindentation studies on rapidly solidified Zr 80Pt 20 and Zr 75Pd 25 binary alloys with nanocrystalline, nanoquasicrystalline, and amorphous microstructures are reported. The results indicate that the hardness and elastic modulus are the highest for a mixture of amorphous and nanoquasicrystalline state among the various microstructures studied. Nanoquasicrystalline phase has high hardness and elastic modulus in comparison to amorphous and nanocrystalline phases. The hardness to modulus ratio is close to 0.1 in both the alloys, irrespective of the phase/phase mixture studied indicating that the bonding in these alloys is of covalent nature. In Zr 80Pt 20, all the phases/phase mixtures have higher hardness and modulus in comparison to similar microstructures in Zr 75Pd 25 due to higher bond energies caused by more negative heat of mixing in the former case. Copyright © 2007 American Scientific Publishers All rights reserved.