Mechanical Properties of Waspaloy Repaired by Laser Metal Deposition and Cold Metal Transfer

The microstructureMicrostructure and mechanical propertiesMechanical properties of additively manufactured WaspaloyWaspaloy were characterized in the industrial context of refurbishmentRefurbishment. Two processes were studied to discuss their advantages and drawbacks considering the targeted application: Laser Metal DepositionLaser metal deposition with powder and Cold Metal TransferCold metal transfer. The resultant microstructuresMicrostructure were compared in the build-up and at the interface between the wroughtWrought base WaspaloyWaspaloy and the additively manufactured part, in the as-built condition and after post-weld heat treatmentsHeat treatment. Tensile and creep propertiesCreep properties were studied along three directions – horizontal, vertical and at the interface – to assess the anisotropyAnisotropy of the build-up and the strength of the interface/Heat Affected ZoneHeat affected zone induced by the metal deposition. Results show that both processes have limited anisotropyAnisotropy in the conditions studied, even though Cold Metal TransferCold metal transfer presents an important crystallographic and microstructural texture. Depending on the process used and heat treatmentsHeat treatment applied, the interface/Heat Affected ZoneHeat affected zone may not be the weakest point of the repaired part despite a neat interface. High temperatureHigh temperature creepCreep results also suggest that post-weld heat treatmentsHeat treatment may not be necessary if this is the primary designDesign criteria. Tensile propertiesTensile properties of Cold Metal TransferCold metal transfer WaspaloyWaspaloy are highly dependent on the deposit thickness from where the specimens are extracted, due to an in-situ heat treatmentHeat treatment that takes place during production of large deposits. The different results are discussed considering the limitations of industrial repairRepair operations such as metal costs, deposition rate, repaired volume and targeted application.