In situ synthesis and thermal shock resistance of a cordierite‐mullite composite for solar thermal storage

Abstract

Cordierite-mullite composite ceramic was synthesized in situ by semidry pressing and pressureless sintering from andalusite, kaolin, γ-Al 2 O 3 , talc, potassium feldspar, and albite in air. The effects of composition and sintering temperature on the density, bending strength, thermal shock stability, crystal phases, and microstructure of the specimens were studied. The results show that specimen B2 (the theoretical content of cordierite was 20 wt%) has excellent performance, that is, a bending strength of 104.59 MPa, 30 cycles of thermal shock resistance without cracking, and a loss rate of 13.12%. X-ray diffractometer (XRD) analysis and scanning electron microscope (SEM) micrographs showed that spherical cordierite crystals were grown on the surface of the mullite, therefore, the specimen possessed a superior bending strength and thermal shock resistance, where a great number of granules combined to restrain crack initiation as well as propagation over time during the thermal shock test. The thermal conductivity of specimen B2 was determined to be 3.83 W/(m·K) (36°C), and the sensible heat storage density was 1136 kJ/kg, with the temperature difference (ΔT) ranging from 0 to 800°C. Consequently, the cordierite-mullite composite is a potentially applicable material for solar thermal storage. K E Y W O R D Scordierite-mullite ceramic, in situ synthesis, solar thermal storage, thermal shock resistance

Reliability and Durability Enhancement of Large-area Mullite-cordierite Composite Substrates for Semiconductor Probe Card

“…In the research of Cheng et al [27], it was reported that the exural strength of the specimen with the best thermal property was about 90 MPa and the loss rate of exural strength was 13.12%, after 30 thermal shock cycles. Compared to the composites reported in previous studies [27,28], the fabricated large-area mullite-cordierite composite substrate has excellent mechanical strength. This is because it has a high exural strength of 200 MPa or more and the rate of change in the exural strength is less than 10%, after 100 cycles of all environmental tests.…”

“…It can be assumed that the thermal stress can generate an impurity, which affects the physical properties [26]. In the research of Cheng et al [27], it was reported that the exural strength of the specimen with the best thermal property was about 90 MPa and the loss rate of exural strength was 13.12%, after 30 thermal shock cycles. Compared to the composites reported in previous studies [27,28], the fabricated large-area mullite-cordierite composite substrate has excellent mechanical strength.…”

Sintering and final properties of kaolinite‐magnesite tapes for the manufacture of cordierite‐mullite ceramics

“…The ternary oxide system MgO‐Al 2 O 3 ‐SiO 2 (MAS) is characterized by two main minerals: cordierite (2MgO.2Al 2 O 3 .5SiO 2 ) and mullite (3Al 2 O 3 .2SiO 2 ), which have been the subject of several studies 1‐5 . However, in the MAS system, cordierite‐mullite composites attract much attention due to its: (i) high chemical and thermal stability; (ii) low expansion coefficient, conductivity, and dielectric constant; and (iii) excellent mechanical resistance at high temperature 4,6,7 .…”

Microscopic regulation of plant morphological pores on mechanical properties of porous mullite materials

“…In recent years, porous materials have been widely used in thermal insulation systems, 1‐2 battery electrodes, 3 solar thermal energy storage, 4‐5 wastewater filtration and adsorption treatment, 6 bone regeneration ceramics, 7‐8 and diesel particulate filters, 9 etc. Porous mullite materials (PMMs) have attracted significant research attention owing to their low thermal expansion coefficient and TC, high‐temperature creep resistance, high thermal shock resistance, excellent high temperature mechanical properties, and large specific surface area.…”