Crack inspection

Detecting cracks early - ensuring integrity

Cracks are among the most critical defects in technical components. They can result from material fatigue, forming processes, heat treatment, grinding processes, or mechanical overload. If left undetected, they can propagate under stress and lead to loss of function or failure.

Crack testing is therefore a central component of quality assurance in safety- and function-critical applications. Depending on the material, component geometry, and suspected crack location, different testing methods are used to ensure reliable detection.

What types of cracks are detected?

The following defects, among others, can be detected during crack testing:

• Surface cracks resulting from mechanical or thermal stress
• Near-surface crack initiation in edge zones
• Fatigue cracks in components subjected to dynamic loading
• Grinding and hardening cracks following machining or heat treatment processes

The selection of the appropriate testing method depends on the material, component thickness, accessibility, and the respective quality requirements.

Testing methods used

Crack testing is not a single method, but rather a testing objective. Depending on the application and material, various non-destructive testing methods are used:

• Magnetic particle testing (MT) - for detecting surface-opening and near-surface cracks in ferromagnetic materials
• Penetrant testing (PT) - for surface-breaking cracks in metallic and non-metallic, non-porous materials
• Eddy current testing (ET) - for rapid detection of near-surface cracks in electrically conductive materials
• Ultrasonic testing (UT) - for detecting internal cracks within the material

For rotationally symmetric mass-produced components, crack testing can also be integrated into fully automated testing systems. Our automated testing machines, for example, feature an integrated acoustic testing unit for automated crack detection.

Typical applications of crack testing

Crack testing is used in particular:

• After mechanical machining or grinding processes
• After heat treatments
• In incoming goods inspection
• During series production
• As part of complaint analyses
• In the maintenance of safety-critical components

Depending on requirements, testing can be performed on a random basis or as a 100% inspection.

Industries and application areas of crack testing

Crack testing is relevant in all industrial sectors where component integrity is critical to safety or function, including:

• Automotive and supplier industry
• Aerospace
• Machinery and plant engineering
• Rail vehicle technology
• Energy and power plant sector
• Metal processing and forging technology

The specific design of the inspection depends on the component, accessibility, lighting conditions, and the respective quality requirements.

Conducting crack inspection at Technomix

Crack inspection is performed based on clearly defined inspection instructions and coordinated defect catalogs. Depending on the material, geometry, and inspection objective, the appropriate inspection method is selected and integrated into the existing quality process.

In addition to manual inspection methods, Technomix also offers automated solutions to handle high volumes with reproducible inspection reliability.

The results are documented in a traceable manner and supplemented with image or profile data in case of anomalies.

Organizational integration takes place within the framework of our quality management system in accordance with DIN EN ISO 9001.