Sintering and crystallization of SrO-CaO-B2O3-SiO2 glass-ceramics with different TiO2 contents

Author(s)

Silva, Lais D. ^{[1, 2]} ; Rodrigues, Alisson M. ^[2] ; Rodrigues, Ana Candida M. ^[2] ; Pascual, Maria J. ^[3] ; Duran, Alicia ^[3] ; Cabral, Aluisio A. ^{[1, 4]}

Affiliation

^[1] Fed Inst Maranhao IFMA, Postgrad Program Mat Engn, BR-65030001 Sao Luis, MA - Brazil

^[2] Fed Univ Sao Carlos UFSCar, Postgrad Program Mat Sci & Engn PPGCEM, Dept Mat Engn DEMa, Ctr Res Technol & Educ Vitreous Mat CeRTEV, BR-13565905 Sao Carlos, SP - Brazil

^[3] CSIC, Inst Ceram & Vidrio, C Kelsen 5, Campus Cantoblanco, Madrid 28049 - Spain

^[4] Fed Inst Maranhao IFMA, Dept Phys DEFIS, BR-65030001 Sao Luis, MA - Brazil

• Document type: Journal article
• Source: Journal of Non-Crystalline Solids; v. 473, p. 33-40, OCT 1 2017.
• Web of Science Citations: 11

Abstract

Glass and glass-ceramics (GCs) of the CaO-SrO-B2O3-TiO2-SiO2 system are promising candidates as sealants for solid oxide fuel cells (SOFCs), mainly because of the possibility of the formation of Sr2SiO4 and Sr(TiO3) as crystalline phases, which minimizes the interfacial reaction between the interconnection elements and the sealant. Four glass compositions of this system, with different TiO2 content, were obtained. The crystalline phases formed after crystallization were identified by X-ray diffraction (XRD). Combining Differential Scanning Calorimetry (DSC) and Optical Microscopy (OM), it was found that the overall activation energy for crystallization did not change with TiO2 content. The predominant crystallization mechanism is controlled by the surface, and the growth of the crystalline layer is governed by diffusion. The sintering behavior was investigated by DSC and Hot Stage Microscopy (HSM). All glass compositions exhibited a single-stage shrinkage behavior, but those with a larger amount of TiO2 showed high sinterability. The measured coefficient of thermal expansion (CTE) varied from 10.2 x 10(-6) K-1 (100-550 degrees C) in the glass to 13.9 x 10(-6) K-1 (100-550 degrees C) in the GCs, which is in good agreement with the typical CTE of SOFC components. These consistent values of the CTE and good sintering behavior allow us to propose that the glass composition with a higher percentage of titanium is a promising candidate for further experimentation and development as a sealant material. (AU)

• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC