Influence of Heat Treatment on Microstructure and Mechanical Properties at Elevated Temperatures of Nonweldable Ni-Based Alloy Printed by Fused Filament Fabrication

The microstructure and mechanical properties of printed specimens of nonweldable MAR-M247 alloy in the sintered state and after different heat treatments are investigated. Specimens are produced using the fused filament fabrication process, which enables the fabrication of crack-free components. The microstructure is characterized by scanning electron microscopy, electron backscatter diffraction, and X-ray diffraction. Tensile tests are conducted at room temperature, 500, 600, and 700?°C. All heat-treated specimens exhibit the formation of ?? (gamma prime) precipitates larger than 500?nm, along with various carbides and equiaxed grain structures. The as-heat-treated specimens at the high subsolvus temperature of 1220?°C show the highest tensile strength with the highest elongation and stable tensile strength up to 700?°C.