Effects of holding time on structure and the properties of spodumene/mullite composite ceramics

Abstract

In this paper, spodumene/mullite ceramics with good thermal shock resistance were prepared from spodumene, quartz, talc, and clay when the sintering temperature was 1270℃. In the sintering process, the effect of holding time on densification, mechanical properties, phase transformation, microstructure, and thermal shock resistance of the composite ceramics were investigated. The phase transition and microstructures of the ceramics were identified via X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The interaction between holding time and bulk density was studied by response surface methodology. The result show that an appropriate holding time can improve the mechanical properties of spodumene/mullite ceramics. When the holding time was kept 90 min, the spodumene/mullite ceramics with the apparent porosity was .47%, the bulk density was 2.28 g/cm3, and bending strength was 63.46 MPa. Furthermore, since no cracks formed after 20 thermal shock cycles for the composite ceramics with a bending strength decreasing rate of 12.66%, it is revealed that spodumene/mullite ceramics exhibit good thermal shock resistance. Therefore, this study can provide beneficial guidance for both industrial production and energy conservation.

Preparation and Performance of Ceramic Tiles with Steel Slag and Waste Clay Bricks

“…These findings indicate that within a certain range, prolonging the holding time can effectively enhance densification of the ceramic material, resulting in reduced pore quantity and increased density. However, excessive holding times lead to over-densification of the ceramic material, causing an increase in apparent porosity as well as surface density while decreasing linear shrinkage [68,69]. XRD patterns presented in Figure 16 illustrate the crystal phase compositions and diffraction peak intensities of the samples fabricated using various soaking times.…”

Effect of holding time on the properties of porous ceramics with high-volume polished slag and its pore structure characteristics

“…The excellent stability of the SiC particles themselves was due to the presence of a protective film of SiO 2 on the SiC surface, which prevents the reaction of SiC with O 2. At high temperatures, the SiO 2 cladding layer is easily destroyed and a silicate liquid phase is formed, resulting in a faster diffusion rate of O 2, which reacts with SiC inside and produces large amounts of CO and CO 2 , which are then retained in these liquid phases and form pores (Schiroky, 1987;Cheng and Chen, 2004;Mergia et al, 2008;Shui et al, 2011;Chen et al, 2012;Wang et al, 2018;Yaqun et al, 2022).…”