Title: Repair of components using additive manufacturing technologies

Abstract

Direct Laser Deposition (DLD) is a versatile, cost-effective and time saving tool to repair worn out or damaged parts compatible with a vast panel of metals and complex geometries. In situ repairing of a component part of a large scale structure may save the complexity of disassembling the host structure using a robot arm to convey the laser beam and the metal powder carrying gas feed. Process parameters include laser beam and powder jet characteristics as well as raster scan strategies and part preparation protocol. The search for the adequate parameter set is at the heart of R&D. For nuclear applications, cobalt-based hardfacing coatings are repaired in spite of their sensitivity to crack formation induced by extensive thermal cycling. For naval applications, we successfully repaired a SS316L sample by restoring its initial corrosion resistance. Samples were made using induction heating assisted DLD and characterized by non-destructive testing, microstructural examinations, mechanical tests and corrosion evaluation performance. The quality criteria (dense deposition, minimum porosity and absence of crack) are met.