Mechanical properties and thermal stress investigations of metal supported SOFC by plasma spraying

• Main Authors: Liang-Yu Lu, 盧亮宇
• Other Authors: Yung-Chin Yang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/94a33w

碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 100 === In this study we deposited LSGM electrolytes, LSCF cathode and LDC/NiO anode coatings individually onto porous Ni-substrates by atmospheric plasma spray were prepared for residual stress analysis. A significant residual stress may lead to micro-cracks in the film or cause the film to peel off the substrate. Therefore, in this work, the biaxial residual stress states of SOFC components by using the sin2ψ technique of the XRD method were studied. The results show that the LDC/NiO anode displays the highest compressive residual strain among the three components. Secondly, we study the biaxial residual stress states of SOFC anode coatings on Ni substrates by using the "sin2ψ" technique of the x-ray diffraction (XRD) method. The results show that the compressive residual strain in the LDC/NiO anode decreases with the increase of Ni substrate temperature during the plasma spraying. Heating the substrate during APS coating process leads to the less mismatch of thermal expansion after cooling down of specimen. Moreover, the bonding strength between the anode and substrate decreases with the increasing compressive residual strain in the coating. The specimen with the highest bonding strength (40.1 MPa) and lowest compressive residual strain (0.36%) was obtained by heating the Ni substrate at 600ºC during spraying process. Finally, we investigated the residual strain of each component in SOFC, which under the cyclic redox treatments. The results show that each sample (LSCM buffer, NiO/LDC, LDC buffer, LSGM, LSCF) reveal compressive residual strain after plasma spraying. However, the strain states of these components become complicated and irregular after the redox treatments.