Microstructure and mechanical properties of the (Fe,Ni)Al-based alloy produced by SLM and HIP of spherical composite powder

Abstract The microstructure and properties of spherical composite powders produced from the β-(Fe, Ni)Al-based alloy by plasma rotating electrode process (PREP) using a steel-shelled electrode were studied. Parameters of the selective laser melting (SLM) mode (laser power density, laser intensity, scan speed and regime) were optimized to ensure the minimal porosity of σ b ) and ductility ( e ) from σ b = 1490 ± 34 MPa at e =  1.2% to σ b = 1650  ±  41 MPa at e =  8.0%. The maximum mechanical properties were observed in the samples produced by HIP: conditional ultimate compressive strength: 2120 ± 60 MPa (which corresponds to the true ultimate compressive stress σ b = 1765 ± 50 MPa) and plastic yield e  = 16.25% ( e  = 0.1774 ) at an offs e t yield point (true yield stress) σ 0.2 = 872 ± 21 MPa. Thermomechanical properties of the (Fe,Ni)Al- based alloy at 873–1373 K was studied. The temperature-force dependence of the steady-state creep rate has been analyzed. The true yield stress equal to 566 MPa was measured at 873 K, logarithmic strain rate 0.001 s −1 , and degree of induced plastic strain 0.2%. It was shown that high-temperature mechanical properties of (Fe,Ni)Al- based alloy has intermediate values in between intermetallic alloy Ni 41 Al 41 Cr 12 Co 6 and Fe-Ni-Gr-Al alloy (EP747).