Figure 1. Photograph of Knudsen Effusion Mass Spectrometry / High Temperature Mass Spectrometry facility (QMS: M/s Hiden Analytical, UK – Hiden HAL/3F RC 1001 PIC series) at Indira Gandhi Centre for Atomic Research – India.
The intermetallic phases formed from aluminium–zirconium metals find potential applications in various fields because of their favourable properties such as resistance to high-temperature oxidation/corrosion, high ductility, non-toxic, non-magnetic, and low density. Various previous investigations have confirmed that aluminium-based alloy’s physical and mechanical properties are improved by adding zirconium, followed by heat treatment. Vaporisation thermodynamic studies on the Al-Zr binary system serve as useful input for fuel (U-Zr-Al) and structural materials (Al-Zr) design and in understanding in-reactor behaviour. Al-Zr alloys are considered potential candidates for structural materials for nuclear fission reactors because of their desirable high-temperature mechanical properties
combined with their low absorption cross-section for thermal neutrons. The knowledge of thermodynamic properties and phase equilibria information of Al-Zr system is also necessary for calculating U-Zr-Al ternary system, which is a proposed nuclear fuel. Vaporisation thermodynamic studies were performed over <ZrAl3(cr)+ZrAl2(cr)> and <ZrAl2(cr)+Zr2Al3(cr)> biphasic region of Al-Zr system by employing Knudsen Effusion Mass Spectrometry (KEMS) in the temperature range between 1233 to 1535 and 1208 to 1458 K, respectively. It was observed that these samples undergo incongruent vaporisation with Al(g) alone in the vapour phase. Following are the recommended p-T relations deduced in the present study:
log(pAl/Pa) = (-18663 ± 132)/T + (12.23 ± 0.10) (1233-1535 K) <ZrAl3(cr)+ZrAl2(cr)>
log(pAl/Pa) = (-18982 ± 112)/T + (11.92 ± 0.08) (1208-1458 K) <ZrAl2(cr)+Zr2Al3(cr)>
From the p-T and K-T relations, based on the second and third law methods of thermodynamics, the enthalpy changes of the following reactions were evaluated:
ZrAl3(cr) = ZrAl2(cr) + Al(g) and 2ZrAl2(cr) = Zr2Al3(cr) + Al(g). Subsequently, the enthalpies of the formation of ZrAl2(cr) and Zr2Al3(cr) were deduced.
Figure 2 (right). Combined second law plot of log(pAl/Pa) vs. 1/T (K-1) over <ZrAl3(cr)+ZrAl2(cr)> and <ZrAl2(cr)+Zr2Al3(cr)> two-phase regions.
Project Summary by: Venkata Trinadh, Indira Gandhi Centre for Atomic Research, Chennai, India.
Paper Reference: Venkata Trinadh, V., Bera, S. and Brahmananda Rao, C. V. S. (2024) ‘High temperature mass spectrometric studies over Zr‐Al binary system: Thermodynamic properties over 3(cr) + ZrAl2(cr) > and 2(cr) + Zr2Al3(cr) > biphasic
regions.’ Rapid Communications in Mass Spectrometry. Wiley, 38(23). DOI: 10.1002/rcm.9914.
Hiden Product: HAL/3F RC 1000 PIC series.
