Leveraging Electron Beam AM for Repair in GTD-111 DS Superalloy using ABD®900-AM

Industrial power-generating gas turbines rely on high-temperature nickel-base superalloys for early-stage rotating buckets in the hot section. These components endure extreme temperatures and stresses, leading to material degradation over time, necessitating reconditioning, repair, or replacement. Sourcing these complex materials has become increasingly difficult due to supply chain constraints and the high demand for nickel-base alloys in aerospace applications. Consequently, the sustainability of gas turbine buckets is becoming a critical concern.

Additive manufacturing (AM) has recently been utilized to print gas turbine components, yielding significant benefits such as improved turbine efficiency, durability, reduced lead times, and cost savings. However, there have been few studies on repairing components using AM. This study explores the use of a novel nickel-base superalloy (ABD-900AM) to simulate repairs in GTD-111, a commonly used alloy for rotating buckets in large industrial power-generating gas turbines.

Electron beam (EB) printed results showed no signs of cracking at the interface between the two materials. A standard recrystallization heat treatment cycle was conducted to enhance the overall grain size in ABD-900 and homogenize the gamma-prime size and distribution in both materials. Detailed characterization in both the as-printed and heat-treated conditions was performed to understand any microstructural differences. High-temperature creep testing results indicated that the overall behavior was comparable to standard EB-printed ABD-900 material in the same heat-treated condition. These findings suggest that ABD-900 EB printing may be a viable repair option for complex nickel-base superalloys.