Research on sintering performance and corrosion mechanism of whisker enhanced MgAl2O4 saggar

• Published in: Ceramics international Vol. 50; no. 22; pp. 47017 - 47023
• Main Authors: Zhang, Hao, Zhang, Han, Xiao, Zixiu, Li, Youqi, Zhao, Huizhong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.11.2024
• Subjects: Corrosion resistance; MgAl2O4; Potassium titanate whisker; Saggar; Sintering property; Corrosion resistance; Sintering property; MgAl2O4; Potassium titanate whisker; Saggar
• ISSN: 0272-8842
• DOI: 10.1016/j.ceramint.2024.09.052

Spinel saggar was prepared using Magnesium Aluminum spinel (MgAl2O4), KF and TiO2 as primary raw materials. The saggar's toughness was enhanced through in-situ generation of potassium titanate whisker (PTW). The impact of sintering temperature on the saggar's phase composition, whisker growth and physical properties was investigated. The findings indicated that the spinel saggar exhibited high densities and robust mechanical strength following heat treatment at 800 °C for 3 h, with an apparent porosity of 27.9 %. The cold modulus of rupture (CMOR) and cold crushing strength (CCS) were measured at 5.58 MPa and 21.05 MPa, respectively. The saggar retained rate 75.6 % of their strength after three thermal cycles at 800 °C for 20 min followed by air cooling. Corrosion analysis identified LiAlO2 as the primary corrosion product of the spinel saggar. PTW facilitated particle bonding, enhancing the strength and toughness of the spinel saggar. This promoted the dispersion and absorption of thermal stresses during cyclic corrosion to prevent further damage. In contrast, for cordierite-mullite saggar corrosion products included LiAlO2, eucryptite(β-LiAlSiO4) and Li4SiO4. The disparate thermal expansion among these phases resulted in the formation of through cracks, exacerbating saggar corrosion damage. The spinel saggar demonstrated superior performance during the cyclic corrosion process.