Effects of Aluminum Oxide Addition on Electrical and Mechanical Properties of 3 mol% Yttria-Stabilized Tetragonal Zirconia Electrolyte for IT-SOFCs

Abstract

Composite tetragonal zirconia (3Y-TZP) sinters with Al2O3 contents of 0, 1, 5, 10 and 15 mol% were obtained from a 3-YSZ powder prepared using the gelatin method, and the influence of alumina addition on the mechanical and electrical properties of the obtained sinters was investigated. Al2O3 was added via two different methods, namely during the preparation of the 3-YSZ powder and via impregnation using an alcohol solution of aluminum nitrate. The obtained green bodies were sintered for 2 h in air at 1773 K. The structure and morphology of the two series of sinters were investigated using XRD and SEM-EDS, their electrical properties were determined using impedance spectroscopy, and their hardness and critical stress intensity factor were measured using the Vickers indentation test. We established that both the amount of alumina and the method used to introduce it into the 3Y-TZP matrix significantly affect the physicochemical properties of the obtained polycrystalline material. The 3-YSZ/10 mol% Al2O3 sinter that had Al2O3 introduced during the preparation of the 3-YSZ powder was found to exhibit the most advantageous mechanical and electrical properties while still having sufficiently low porosity.

Net‐shaping of advanced ceramic composites by gelcasting into precision molds made by rapid‐prototyping

“…Fracture toughness of the alumina composite with 3 wt% α‐alumina platelets has substantially improved over that of pure alumina, with a marginal reduction in the flexural strength. K Ic of the YSZ composite has shown remarkable enhancement to be 8.43 MPa√m, over the reported values of 3–5 MPa√m 35,36 for pure YSZ.…”

“…YSZ without inclusions is reported to yield a fracture toughness of 3-5 MPa√m. 35,36 The YSZ composite with coated platelets (5 wt%) has exhibited a substantial rise in fracture toughness to 8.43 MPa√m. Those values are substantially high for the ceramic systems.…”

“…Platelet inclusions (3 wt%) in the alumina composite have enhanced the fracture toughness to 4.74 MPa√ m . YSZ without inclusions is reported to yield a fracture toughness of 3–5 MPa√m 35,36 . The YSZ composite with coated platelets (5 wt%) has exhibited a substantial rise in fracture toughness to 8.43 MPa√ m .…”

Three-Dimensional-Printed Molds from Water-Soluble Sulfate Ceramics for Biocomposite Formation through Low-Pressure Injection Molding

“…Nevertheless, the amount of the zirconia that was added was not limited by 5 wt.% and its influence on the mechanical characteristics of various ceramic composites is an interesting object for the further studies. The increase in hardness could possibly be obtained in a similar way as for the zirconia tetragonal alumina composites (ZTA) [64,65]. Effective toughening could also shift the application of such materials to the processes of medium pressure injection molding (MPIM) [66] and high-pressure injection molding (HPIM) [67].…”