Mechanical Properties Evaluation Method for Non-Stoichiometric Materials under High Temperature and Oxidizing/Reducing Conditions

Abstract

For the commercialization of solid oxide fuel cell (SOFC), in addition to the electrochemical reliability, it is also important to ensure the mechanical reliability of SOFC. Thus, the establishment of a suitable mechanical testing method under various temperatures and oxygen partial pressure conditions is a prerequisite for the development of reliable SOFCs. In this study, the in-situ mechanical testing method was developed in order to investigate mechanical property (i.e.: Elastic modulus and Fracture strength, Creep and Fatigue property) of solid oxide fuel cells components under high oxidizing/reducing environments. And mechanical property of gadolinium doped ceria (Gd 0.1 Ce 0.9 O 2-δ ; GDC) as oxygen non-stoichiometric compounds were evaluated in oxygen partial pressures under reducing conditions by developed In-situ mechanical testing machine. The experimental results of the investigation of elastic modulus and fracture strength on the SOFC components, the fracture stress of GDC were almost constant regardless of oxygen partial pressure, while elastic modulus decreased with decreasing oxygen partial pressure in reducing atmospheres. Mechanical properties of SOFC materials should be characterized by in-situ method because these results are different to quench method.

Identification of Ni-YSZ Anode Creep Property Using PSO for Multiscale Simulation

“…Therefore, when we optimize transit creep on Ni-YSZ cermet, we should apply not only Norton law but also Strainhardening law to experimental creep curve. Norton law and Strain-hardening law are generally described by equation [6] and [7]:…”

“…Mechanical Testing Equipment. In our previous study, we had developed material testing equipment that could evaluate mechanical properties under controlled gas flow and evaluated temperature conditions (6,7). This machine was designed to be applied to tensile and compression tests, three and four point bending tests, and small punch tests.…”

High-Temperature Elastic Properties of Yttrium-Doped Barium Zirconate

“…During the operation of conventional SOFCs, a high mechanical stability must be ensured. Consequently, the stress conditions and mechanical stability of SOFCs and constituent materials have been widely examined [18][19][20][21][22][23][24][25][26][27][28][29]. Although PCFCs operate at a lower temperature than that of SOFCs, large thermal stresses are introduced owing to the several thermal cycles during operations.…”