Early Intervention Inspection of Hot-Forged Components

The manufacture of Titanium Ti64 billets by gas ingot conversion induces shrinkage, liberating gas which may cause porosity, and potentially voids. Methods of early intervention (i.e. in-process) are necessary to feedback structural integrity status thus preserving cost efficiencies by limiting exposure of virgin material to potentially flawed manufacturing processes. 

There is the potential for a number of defects to arise during hot-forging. These include: laps, cold shuts, surface/sub-surface cracking, inclusions, and corrosion. Detecting abnormalities prior to the solidification stage can avoid material stresses arising due to unintended inclusions not similarly elongating with the surrounding material. Flaws within the macro-zone can result in voids and cracks which, undetected, culminate in catastrophic failure (e.g. shearing). Current non-destructive testing (NDT) methodologies include visual inspection, magnetic particle inspection (MPI), radiography and penetrant testing (PT). However, they all have limitations when considering complete coverage.

Ultrasonic Testing (UT) is sufficiently sensitive for surface and sub-surface discontinuities. Phased array ultrasonic testing (PAUT) of forgings has proven beneficial for volumetric inspection due to their fixed beam positioning. However, these processes require coupling with the component under inspection using a water- or oil-based gel. For rough surfaces or varied temperature processes, the efficacy (or appropriateness) of the couplant diminishes. This project will focus on the development of an inspection methodology able to yield quantitative information concerning the detection, localisation and characterisation of defects during the forging process. Key considerations will focus on scan time, data quality, and data analysis methods. The outputs of this project will feed in to Future Forge focusing on tighter process control, reduction in non-conformance, and enhanced strategies for titanium alloys.

Consideration of data analytics will be a priority to ensure NDT alignment with NDE 4.0. This industry-focussed approach will help to strengthen supply chain services and provide an academic and sector aligned pathway towards Industry 4.0.

Research outcomes must converge and align with industry standards and support the National Manufacturing Institute Scotland (NMIS) partnership with industry stakeholders, to maintain a collaborative and collegiate relationship.