Broaching of Ti-6-4 - Detection of workpiece surface anomalies on dovetail slots through process monitoring

Surface anomalies induced by abusive broaching represent a concern for the safety of critical components of aero-engines. Using acoustic emission and force signals, the paper reports on process monitoring techniques to detect surface anomalies when abusively broaching dovetail slots in Ti-6-4. Parallel surface inspection helped in defining the correlation between the occurrence of uneven events in the output signals and the appearance/location of anomalies on the broached surfaces. The findings support the definition of process monitoring strategies to detect workpiece surface anomalies including surface deformation/overheating, directed scoring and smearing of parent material.