Enthalpy of formation of intermetallic phases from Al–Zr system determined by calorimetric solution method

Abstract

Intermetallic phases represent a group of materials of unique properties. Many of those materials have found practical application, whereas others are still intensively examined. There are ten stable intermetallic phases in Al-Zr system, among which few are prospective materials to work at elevated temperature, nuclear reactors, etc. On top of that, researches are focused on obtaining amorphous phases, nanoparticles and zirconium-based pressure pipes covered with aluminum. As a result, better understanding of thermal effects accompanying those compounds formation becomes crucial. In this paper, solution calorimetry method was used for determination of formation enthalpy D f H of intermetallic phases from Al-Zr system at room temperature (298 K). Experiments were conducted using test station built by author. Material used as bath was aluminum. Additionally, alloys preparation methodology was described and presented. Calorimetric measurements were taken on phases: Al 3 Zr, Al 2 Zr, Al 3 Zr 2 , AlZr, Al 2 Zr 3 , AlZr 2 and AlZr 3 . Heat of dissolution of zirconium in aluminum bath at temperature 1073 K was determined experimentally and was equal to -244.5 ± 5.4 kJ mol -1 . Obtained results of enthalpy of formation were summarized and compared with the literature data.