How to Analyze Automotive Thermoplastic Parts for Failure

Thermoplastic parts can fail. This is no secret. However, when it has happened it is crucial to find out the reason for the failure of a part. Then, removing the cause of defect takes priority.

For the analysis of the cause of failure of injection-molded thermoplastic parts, a superior level of expertise in material science, production methods and analytical instrumentation is required. There is a wide array of failure scenarios that can occur. Possibilities range from misuse and unintentional service conditions to design faults, molding issues, ContrainteLa Contrainte est définie par un niveau de force appliquée sur un échantillon d’une section bien définie. (Contrainte = force/surface). Les échantillons qui possèdent une section rectangulaire ou circulaire peuvent être comprimés ou étirés. Les matériaux élastiques comme les élastomères peuvent être étirés jusqu’à 5 à 10 fois leur longueur initiale.stress, overload and degradation.

Thermal analysis instruments are powerful tools for failure analysis. Here is a short list of thermal analysis techniques and which questions they can answer in your failure analysis:

Differential Scanning Calorimetry

Was the material contaminated with a different material?
Did the supplier provide the correct material composition for my thermoplastic part?
What is the crystallinity of the material? Is there any potential for Post Crystallization (Cold Crystallization)The post crystallization of semi-crystalline plastics occurs primarily at elevated temperatures and increased molecular mobility above the glass transition.post-crystallization?

Thermogravimetric Analysis

Was the material filled with the right amount of fillers, plasticizer and modifiers?
Was the material thermally stable to withstand service temperatures?
Did the material absorb water?

Thermomechanical Analysis

Did the material change its dimensions at service temperatures?
Was there residual ContrainteLa Contrainte est définie par un niveau de force appliquée sur un échantillon d’une section bien définie. (Contrainte = force/surface). Les échantillons qui possèdent une section rectangulaire ou circulaire peuvent être comprimés ou étirés. Les matériaux élastiques comme les élastomères peuvent être étirés jusqu’à 5 à 10 fois leur longueur initiale.stress in the molded part?

Dynamic-Mechanical Analysis

Did the material have the same mechanical properties at service temperatures?
Did the material degrade at a faster rate than anticipated?
Did the material lose its mechanical properties due to liquid interactions?

These few questions give you a short overview of the wide field of questions in failure analysis that can be answered with thermal analysis instrumentation.

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