Failure analysis, at its most basic, is a systematic scientific process that is used to deduce why a product, component, or process failed. Failures can occur during manufacture, shipping and installation, and service. As a result of the data collected and its analysis, possible causes of failure are determined. Corrective actions can then be undertaken to prevent future failures.
To understand the causes of failures and prevent future occurrences, a multi-disciplinary approach is generally needed. Various disciplines including material science, mechanical engineering, and instrumental chemical analysis may be required to thoroughly evaluate the product function, design, fabrication methodology, processing, installation, and maintenance. All of these factors singly or in synergistic combination can lead to failure.
Some common steps to performing failure analysis include:
- Data Collection: Information is collected about the circumstances of product failure and historical information. Engineering design, manufacturing methods, material specifications, maintenance records and other pertinent information are collected during the failure analysis planning process.
- Non-Destructive Testing: Product is analyzed visually, and with NDT evaluation methods to identify flaws, cracks, and other anomalies that may have contributed to the failure.
- Destructive Testing: Laboratory analysis is used to identify the material structure, mechanical properties, and physical properties of the failed component. Environmental contributors such as corrosive materials or contaminants would also be investigated.
- Analysis of Data: Utilizing the historical and analytical information along with failure analysis experience the analyst can identify the mechanisms of failure and any contributing factors.
- Investigation Completion: Conclusions and recommendations from the investigation are presented along with any potential corrective actions to prevent future failure reoccurrence.
FAILURE ANALYSIS TESTING Methods
- Visual Examination evaluates the condition of the failed product in its initial state as well as during disassembly or dissection. Includes examination by optical and digital microscopies, dimensional measurement, and photo documentation of all relevant features.
- Investigative chemical analysis determines whether the materials of manufacture (alloy, coatings, etc.) meet specification. This helps the analyst determine if any deviations are pertinent to the failure or if the materials are suitable for the intended service.
- Residual analysis, a subset of chemical analysis, looks for contaminants from either manufacturing processes or the environment that may have led to such failure mechanisms as corrosion, stress corrosion cracking, etc.
- Fractography employs optical and scanning electron microscopes to identify fracture mechanisms. Characteristic features can reveal where a crack started, how it propagated, and whether it was fracture, wear, corrosion or creep or some combination of these.
- Mechanical testing determines the properties of the failed component including tensile properties, ductility, hardness, fatigue properties, and so forth.
- Material evaluation examines material structure, grain size, coating thickness and integrity, density, and other characteristics that affect performance, along with identifying anomalies.
Failure analysis is a very complicated systematic process requiring extensive knowledge and experience in order to reach the proper conclusions. It is an indispensable tool for manufacturing troubleshooting in all industries as well as a supplement in forensic legal examination.
For a thorough understanding of IMR Test Labs Failure Analysis Capabilities, click here.