부산대학교 도서관

Purpose: An accelerated life test (ALT) plan was devised after investigating the potential failure mechanisms of a ceramic disk material for a water valve. Moreover, ALT was implemented to establish a life distribution and acceleration model. Methods: The thermal shock behavior of the ceramic disk was predicted using finite element method. To reproduce the disk, a jig was fabricated and then the ALT was performed. After the test, failure analysis was conducted through optical microscopy and surface roughness measurement. Results: The life distribution of the ceramic disk for the water valve was confirmed to have a Weibull distribution with a shape parameter of 1.5. Moreover, because the operating condition was thermal shock acceleration, the acceleration model was suitable when the Coffin-Manson model with a material constant of 6.6 was applied. Conclusion: The analysis of the average values and standard deviations of the surface roughness of failed products using ALT showed that the more severe the environment, the greater the wear of the ceramic disk. This indicated that ALT was well planned and implemented.