Effect of calcined halloysite addition on mechanical strength and deformation behavior of ceramic tableware

This study investigates the effect of adding 0.1, 0.3, 0.6, 1.0, 2.0 wt.% halloysite clay, which is calcined at 600 °C, to the standard ceramic tableware slurry. The test specimens were fabricated by pressing of granulated compositions and subsequently sintering at 1180 °C for 2 h. Detailed deformation, mechanical and microstructure characterization studies were done on sintered samples. All sintered samples with halloysite exhibited higher bending strength than the standard sample. The sample with 1.0 wt.% calcined halloysite showed the highest bending strength (12.80 MPa) and the lowest pyroplastic deformation (1.15 × 10 −5 cm −1 ) among all the samples. Phase analysis and microstructural investigations revealed a significant increase in needle-like mullite phases within the microstructure at this optimal halloysite concentration. These findings suggest that the augmented interlocking of mullite grains contributes to improved mechanical strength and reduced deformation. This study demonstrates halloysite addition might enhance the technological properties of conventional tableware to achieve a reduced thickness in line with current market trends and environmental considerations.