L. D. Hanke, Materials Engineering and Evaluation, Inc., Plymouth, MN
Environmental stress cracking (ESC) is one of the most insidious failure mechanisms for structural polymer components. ESC failures can occur with very little warning and with catastrophic consequences. A combination of tensile stress and a damaging chemical environment is necessary for ESC, and the mechanism is a time-dependent phenomenon that usually manifests as a delayed failure. The tensile stress required for failure can be a fraction of the materials tensile strength and failure of some polymers can occur in seemingly innocuous environments. ESC is a major problem for long-term service reliability, so better understanding and diagnosis of failures has important economic implications. This presentation will discuss techniques for analysis of polymer failures with emphasis on methods for characterization of ESC failures. Several case studies will be included.
Summary: Environmental stress cracking (ESC) is one of the most insidious failure mechanisms for structural polymer components. ESC failures can occur with very little warning and with catastrophic consequences. A combination of tensile stress and a damaging chemical environment is necessary for ESC, and the mechanism is a time-dependent phenomenon that usually manifests as a delayed failure. The tensile stress required for failure can be a fraction of the materials tensile strength and failure of some polymers can occur in seemingly innocuous environments. ESC is a major problem for long-term service reliability, so better understanding and diagnosis of failures has important economic implications. This presentation will discuss techniques for analysis of polymer failures with emphasis on methods for characterization of ESC failures. Several case studies will be included.
