| Abstract Scope |
By controlling additive manufacturing process, particularly Laser Powder Bed Fusion process, significantly different microstructure 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 study, fine and stable carbides for Carbide Dispersive Strengthening (CDS) to improve not only general materials properties but more critically to provide strengthening mechanisms above γ' solvus temperature for extreme environment applications such as hypersonic leading edge and combustion devices. Uniaxial tensile data were obtained for Laser Powder Bed Fusion of Haynes 230 at temperatures from 982 to 1177°C. The data is analyzed in terms of the strain rate sensitivity m and the stress dependence n. These two parameters are used to provide insight into the possible deformation mechanisms controlling plastic flow in this alloy over the temperature – strain rate range of interest. The values obtained suggest that under the present experimental conditions Haynes 230 deforms by a combination of dislocation slip and diffusion mediated recovery within the grain interior. Stress – strain curves exhibit oscillations suggesting the material is undergoing dynamic recrystallization during the tensile test. Optical imaging of the gage sections confirms the presence of dynamic recrystallization. |