Publication Date:
2017-02-18
Description:
Synthesis, characterization and density functional theory calculations have been combined to examine the formation of the Zr 3 (Al 1– x Si x )C 2 quaternary MAX phases and the intrinsic defect processes in Zr 3 AlC 2 and Zr 3 SiC 2 . The MAX phase family is extended by demonstrating that Zr 3 (Al 1– x Si x )C 2 , and particularly compositions with x ≈0.1, can be formed leading here to a yield of 59 wt%. It has been found that Zr 3 AlC 2 - and by extension Zr 3 (Al 1– x Si x )C 2 - formation rates benefit from the presence of traces of Si in the reactant mix, presumably through the in situ formation of Zr y Si z phase(s) acting as a nucleation substrate for the MAX phase. To investigate the radiation tolerance of Zr 3 (Al 1– x Si x )C 2 , we have also considered the intrinsic defect properties of the end-members. A -element Frenkel reaction for both Zr 3 AlC 2 (1.71 eV) and Zr 3 SiC 2 (1.41 eV) phases are the lowest energy defect reactions. For comparison we consider the defect processes in Ti 3 AlC 2 and Ti 3 SiC 2 phases. It is concluded that Zr 3 AlC 2 and Ti 3 AlC 2 MAX phases are more radiation tolerant than Zr 3 SiC 2 and Ti 3 SiC 2 , respectively. Their applicability as cladding materials for nuclear fuel is discussed.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Permalink
