Micromechanical Characterization of Ce0.8Gd0.2O2‐δ–FeCo2O4 Dual Phase Oxygen Transport Membranes. Issue 6 (3rd March 2020)

• Record Type: Journal Article
• Authors: Zeng, Fanlin; Malzbender, Jürgen; Baumann, Stefan; Schulze-Küppers, Falk; Krüger, Manja; Nijmeijer, Arian; Guillon, Olivier; Meulenberg, Wilhelm Albert
• Is Part Of: Advanced engineering materials. Volume 22:Issue 6(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-03
• Subjects: ceramic composites -- indentations -- mechanical properties -- microstructures -- oxygen transport membranes; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201901558
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Aiming toward an optimization of dual phase oxygen transport membrane materials for oxygen separation applications, ceramic composites consisting of a Ce1− x Gd x O2− δ (0 < x < 0.2) fluorite phase, Gd0.9 Ce0.1 Fe0.8 Co0.2 O3 perovskite phase, Fe x Co3− x O4 (0 < x < 1) spinel phase, and CoO rock salt phase are developed and micromechanical properties (elastic modulus and hardness) of x Ce0.8 Gd0.2 O2− δ : (1− x )FeCo2 O4 (50 wt% ≤ x ≤ 90 wt%) composites are characterized via indentation testing at room temperature. The results obtained at low indentation loads indicate that the magnitude of the elastic moduli of the different phases is in the order Gd0.9 Ce0.1 Fe0.8 Co0.2 O3 > Ce1− x Gd x O2− δ ≈ Fe x Co3− x O4 > CoO, and furthermore, hardness values are also in the same order. The hardness values of the obtained composites at higher impression loads reveal a stronger dependency on porosity than on composition due to similar hardness values of the main phases. Any compositional effect appears to diminish above a porosity of ≈1%. Abstract : The grain sizes of ceramic composite membranes are optimized for mechanical property assessment via indentation testing. The results reveal that the hardness of the composites is more strongly dependent on porosity than on composition. But the influence of the porosity on the elastic modulus of the composites is only significant at a porosity above ≈1%.