A methodology to increase a strength and guarantee a reliability of an Al2O3/SiC composite ceramics component by crack-healing and proof testing

Abstract

Structural ceramics are brittle and sensitive to flaws. As a result, the structural integrity of a ceramic component may be seriously affected by inherent flaws. Self-crack-healing is an excellent answer to this problem. At the moment, however, there is no technique to heal embedded flaws. Therefore, a technique to guarantee the reliability of ceramics components is demanded, and thus a technique using crack-healing followed by proof test was developed by K. Ando et al to accomplish this. With this technique, testing on the mechanical behavior of the crack-healed zone is very important for ensuring the structural integrity of ceramic component. In this study, firstly Al2O 3/SiC composite with excellent crack-healing ability was sintered. Secondly, a semicircular groove was hardly machined using a diamond ball-drill. Third, a proof test was carried out on the crack-healed sample. Last, using the crack-healed and proof-tested sample, a fracture test was carried out at 1373 K. The measured local fracture stress (σlf) was compared with the theoretical minimum fracture stress guaranteed (σGT) at 1373 K. As the results, σGT showed good agreement with the σLF at 1373 K. Thus, the crack-healing followed by proof test was an excellent technique to guarantee the reliability of machined Al2O3/SiC composite.