THROUGH-LIFE RELIABILITY MANAGEMENT OF STRUCTURAL CERAMIC COMPONENTS USING CRACK-HEALING AND PROOF TEST

摘要

To overcome decrease in component's mechanical properties and reliability, crack-healing could be a very useful technology. In the present study, firstly, strength recovery of Al{sub}2O{sub}3/SiC specimen with a semicircular groove by crack-healing was investigated for improving the structural integrity of machined alumina and reducing machining costs. Secondly, using the crack-healing, a new methodology to guarantee the reliability of ceramic components before service [crack-healing + proof test] was proposed. Thirdly, if a crack initiated during service, reliability would be severely impaired. Therefore, if a material can heal a crack during service, and if the healed zone has enough strength at the temperature of healing, it would be very desirable for structural integrity. From the above points of view, a new methodology to guarantee the structural integrity of ceramic components using in situ crack-healing was proposed and the usefulness is discussed using the test results in terms of crack-healing behavior and proof test theory proposed by authors.