Mullite macro-needles for reinforcement of refractory castables

Abstract

Ceramic macro-needles incorporation as reinforcement in commercial refractory castable was studied. Ceramic macro-needles (Ø2x20 mm) were made from kaolinite clay and gibbsite to obtain mullite as the main crystalline phase. Specimens with the ceramic reinforcement were evaluated by compression after being treated at two temperatures (815 and 1400 °C). The results were compared with those obtained using the same commercial concrete but reinforced with steel fibers and without reinforcement. Compression values presented by specimens with ceramic macro-needles were 74% and 50% higher than specimens with steel fibers after exposition to 815 and 1400 °C, respectively. Based on these results, it was established that ceramic macro-needles are a feasible solution to improve the mechanical resistance of castables exposed to high temperatures.

Remarkably improved nonlinearity and thermal stability of CaYNbMnO7 thermosensitive ceramics via the cold‐sintering process

“…The GSAS software was employed for the Rietveld refinement and the quantitative phase determination. 21 Differential scanning calorimetry and thermogravimetric (DSC) were performed by means of a NETZSCH STA449F analyzer and heated from room temperature up to 1400 • C at a rate of 10 • C/min in nitrogen flow.…”