Reinventing H230 Through Additive Manufacturing with Breakthrough Performance Gain

By controlling additive manufacturingAdditive manufacturing process, particularly Laser Powder Bed FusionLaser Powder Bed Fusion (PBF-L) process, significantly different microstructureMicrostructure and constituents’ formation and distribution can be achieved robustly for superior materials properties gain without altering the bulk materials chemistry. Furthermore, a supersaturated solid solution structure can be obtained without solution treatment and subsequent quench operation to attain optimized properties by forming a high-volume fraction and uniformly distributed fine strengthening phase. In this work, it is demonstrated through additive manufacturing, nano sized and temperature stable carbides (tungsten carbide) for Carbide Dispersive Strengthening (CDS)Carbide Dispersive Strengthening (CDS) were formed to improve not only general materials properties but more critically to provide strengthening mechanismsStrengthening mechanisms above traditionally γ′ solvus temperature range for extreme environment applications such as hypersonic leading edge and combustion devices. Uniaxial tensile data were obtained for Laser Powder Bed FusionLaser Powder Bed Fusion (PBF-L) of Haynes 230Haynes 230 at temperatures from 982 to 1177 °C. The data is analyzed in terms of the strain rateStrain rate sensitivity m and the stress dependence n. These two parameters are used to provide insight into the possible deformation mechanismsDeformation mechanisms controlling plastic flow in this alloy over the temperature–strain rateStrain rate range of interest. The values obtained suggest that under the present experimental conditions Haynes 230Haynes 230 deforms by a combination of dislocation slip and diffusionDiffusion mediated recovery within the grain interior. Stress–strain curves exhibit oscillations suggesting the material is undergoing dynamic recrystallizationDynamic recrystallization during the tensile test. Optical imaging of the gage sections confirms the presence of dynamic recrystallizationDynamic recrystallization.