Electrospark Deposition for the Repair of Army Main Battle Tank Components

This report discusses the successful application of electrospark deposition ESD to reclaim expensive U.S. Army main battle tank components which had no other means of being repaired. The components included the M1A1 main battle tank cradle fabricated from AISI 4130 steel, then chrome plated and the M1A1 helical sun gear shaft chrome-plated AISI 9310. These parts had exhibited large corrosion pits and wear in service. Systems were dead-lined based on the discovery of these anomalies during inspection and the fact that insufficient replacement parts were available. There was no approved repair procedure for these components, and conventional weld repair technologies had been eliminated at Anniston Army Depot ANAD, AL, to repair large pits. Approximately 8 of the vehicles overhauled at ANAD were defective, and deeply corroded parts were removed from the systems and put in storage. Emphasis of this report is placed upon the ESD process development and qualification.