| About this Abstract |
| Meeting |
2011 TMS Annual Meeting & Exhibition
|
| Symposium
|
Bulk Metallic Glasses VIII
|
| Presentation Title |
Effect of Tantalum Substitution on the Crystallization Kinetics and Hydrogen Permeability of Ni-Nb-Zr Amorphous Alloys |
| Author(s) |
Sang-Mun Kim, Narendra Kumar Pal, Wen-Ming Chien, Joshua Lamb, Anjali Talekar, Dhanesh Chandra, Michael D. Dolan, Stephen N. Paglieri, Ted B. Flanagan |
| On-Site Speaker (Planned) |
Sang-Mun Kim |
| Abstract Scope |
Amorphous ternary Ni-Nb-Zr and quaternary Ni-Nb-Zr-Ta alloys are promising hydrogen permeable membranes. Amorphous alloy membranes were prepared by melt-spinning technique. The crystallization temperature and kinetics of amorphous membranes were examined by using differential scanning calorimetry (DSC) under various heating rates. It was observed that crystallization of amorphous (Ni<SUB>0.6</SUB>Nb<SUB>0.4</SUB>)<SUB>70</SUB>Zr<SUB>30</SUB> and (Ni<SUB>0.6</SUB>Nb<SUB>0.4</SUB>Ta<SUB>0.1</SUB>)<SUB>70</SUB>Zr<SUB>30</SUB> alloys proceed through two exothermic reactions. Ta substitution resulted in slight decrease in the primary crystallization temperature (T<SUB>x1</SUB>) but increase in secondary crystallization temperature (T<SUB>x2</SUB>). The activation energies, E<SUB>a</SUB>, of amorphous alloys have been calculated using Kissinger and Ozawa equations based on DSC data. The activation energies for crystallization of amorphous (Ni<SUB>0.6</SUB>Nb<SUB>0.4</SUB>)<SUB>70</SUB>Zr<SUB>30</SUB> alloy are determined as 548 kJ/mol and 534 kJ/mol, respectively. The (Ni<SUB>0.6</SUB>Nb<SUB>0.4</SUB>Ta<SUB>0.1</SUB>)<SUB>70</SUB>Zr<SUB>30</SUB> membrane shows slightly higher values of E<SUB>a</SUB> (579 kJ/mol and 563 kJ/mol). Ta substitution on the crystallization kinetics and hydrogen permeability of amorphous alloys will be discussed in detail. |
| Proceedings Inclusion? |
Undecided |