Effect of Pre-Crack Size and Testing Temperature on Fatigue Strength Properties of Crack Healed Mullite.

Crack-healing behaviour of mullite/SiC/Y2O3 composites and its application to the structural integrity of machined components

“…As to objective (3), the basic crack-healing behaviour of an indented crack was studied systematically in terms of the functions of crack-healing temperature and time, the crack-healing mechanism, and the resultant strength behaviour of the crack-healed components at elevated temperatures. [1][2][3][4][17][18][19] However, the strength recovery behaviour of machined component have not yet been studied. 20 Applying the high crack-healing ability of ceramics to structural components for engineering use could result in great benefits, such as the increased reliability of the structural ceramic components and reduced inspection, machining, and polishing costs for the ceramic components.…”

“…However, a large self-crack-healing ability was successfully induced similar to that of Al 2 O 3 /SiC [5][6][7][8][9][10] and Si 3 N 4 /SiC [11][12][13][14][15][16] by adding 15-20 mass% nano-size SiC particles. [1][2][3][4] Especially, the mullite/SiC composite exhibits very interesting in situ crack-healing ability at 1273-1473 K. [17][18][19] In other words, the mullite/SiC can heal a crack even under 5 Hz cyclic stress and exhibit the same fatigue limit as the base material at the healing temperature. As to objective (3), the basic crack-healing behaviour of an indented crack was studied systematically in terms of the functions of crack-healing temperature and time, the crack-healing mechanism, and the resultant strength behaviour of the crack-healed components at elevated temperatures.…”

“…[1][2][3][4] However, the fracture toughness is low yet; thus, the mullite/SiC is very sensitive to flaws such as cracks and pores.…”

“…As to objective (2), monolithic mullite has no crackhealing ability. However, a large self-crack-healing ability was successfully induced similar to that of Al 2 O 3 /SiC [5][6][7][8][9][10] and Si 3 N 4 /SiC [11][12][13][14][15][16] by adding 15-20 mass% nano-size SiC particles.…”

Crack-healing behavior and resultant strength properties of silicon carbide ceramic

“…Recently, one of the authors developed silicon nitride, 8-10 mullite 11,12 and alumina 13,14 with very high crack-healing ability. If a SiC were able to exhibit high crack-healing ability similar to the above ceramics, it would be very desirable for structural integrity.…”