Why are Inconel, Hastelloy, and Titanium alloys used in WAAM?
Material Selection for WAAM
In Wire Arc Additive Manufacturing (WAAM), material choice is driven by mechanical performance, weldability, and high-temperature stability. Alloys such as Inconel 718, Hastelloy X, and titanium grades like Ti-6Al-4V combine good arc stability with resistance to distortion and oxidation. This makes them suitable for layer-by-layer deposition without compromising structural integrity.
Nickel-based alloys such as Inconel and Hastelloy maintain high tensile strength at temperatures exceeding 800 °C. Their weldability and controlled solidification behavior allow WAAM to achieve fully dense builds with minimal cracking. These alloys are widely applied in turbine cases, combustor liners and high-pressure ducts, often followed by post-process treatments to enhance fatigue resistance.
Titanium Alloys for Lightweight Structures
Titanium alloys provide the best strength-to-weight ratio for WAAM applications where weight reduction is critical—especially in aerospace and aviation applications. Alloys such as Ti-6Al-4V exhibit excellent layer adhesion and low residual stress, enabling the production of large, near-net-shape structures without excessive distortion. They can be efficiently finished through CNC machining to achieve tolerance requirements.
For demanding environments that involve creep and oxidation control, both nickel-based and titanium alloys can be further optimized using thermal barrier coatings to extend service life.
Application and Performance
The combination of WAAM with these materials enables cost-effective production of large components that would be challenging or uneconomical to forge or cast. Industries such as power generation and oil and gas benefit from corrosion-resistant Hastelloy structures, while aerospace sectors rely on titanium and Inconel for lightweight yet high-temperature assemblies. These alloys offer a stable process window for WAAM, supporting strong metallurgical bonding and minimal porosity.
