Comparison of Residual Stress Measurement Methods in Solid Oxide Fuel Cell

Abstract

We performed in-situ measurement of residual stress in an anode-supported cell using sin2 ψ method, cosα method, and Raman scattering spectroscopy. Residual stress at room temperature was evaluated by the sin2 ψ method, cosα method, and simulation. The stress values were generally consistent among the methods, with YSZ having a compressive stress of around 600 MPa. Residual stress analysis at high temperatures was attempted using Raman scattering spectroscopy which, however, was difficult to be applied above 700˚C. Instead, cosα method was successfully utilized for the measurement of residual stress during the temperature rise, reduction, and re-oxidation processes. The stress on the electrolyte observed during reduction and re-oxidation was different from that expected with a simple assumption of layered homogeneous sheets. These results showed that the cosα method is the most suitable method for in-situ measurements to validate simulated stress states.