Post-Weld Heat Treatment of Additively Manufactured Inconel 718 Welded to Forged Ni-Based Superalloy AD730 by Linear Friction Welding

A new post-weld heat treatment (PWHT) cycle was designed for novel dissimilar linear friction welding (LFW) of selective laser melted (SLM) Inconel 718 (IN718) to AD730 forged nickel-based superalloy. The microstructure and hardness the joints after PWHT are investigated compared with those as-linear welded samples. precipitation γ′ + γ″ is determined as main mechanism increase mechanical properties SLM IN718 alloy. These particles coarsened during at 1253 K double aging. results show that thermomechanical history can affect alloy such morphology δ phase solution (ST) from platelike in weld zone (WZ) needlelike base material (BM). It found AD730, nanometric size reprecipitated close line rapid cooling welding. presence ultrafine coarsening remaining alloy, PWHT, enhance strength hardness. developed resulted uniform across joint.