TWI Industrial Member Report Summary 1045/2013
By A J Dack and M E Nunn
Electron beam (EB) welding and materials processing is often used for precision work where the acceptable tolerances are narrow and machine parameter reproducibility is imperative. For critical applications process conditions are developed to reduce flaw/defect levels, although an in-depth appreciation of the machine qualities required to achieve consistent reproducible results is often lacking in a production environment. Effective monitoring of beam qualities is required to ensure quality assurance, enable the transfer of processing between EB machines and to ensure accurate assessment of new production equipment.
This report details the use of TWI's Mk3 beam probing and analysis system, BeamAssureTM, to determine laboratory and industrial beam qualities and to determine the relationship of those qualities to weld integrity. Laboratory tests were made at TWI; industrial deployment was within a highly controlled aerospace production facility which is a major user of EB welding.
Cost savings are the primary industrial drive. Saving costs in aerospace, nuclear and general engineering through ensuring high quality, right first time, outputs from EB welding, processing and additive manufacturing equipment.
- The ability of the probe system to detect subtle changes in electron beam quality immediately prior to welding has been shown.
- Relation of measured beam quality records to physical weld section profiles, and hence integrity, has been established.
- System consistency of performance and benefits when deployed in a production environment have been shown.
- Added benefits of identifying, and being able to act on, otherwise unidentified machine issues (in deflection and mechanical axes) are evident.