Solidification microstructure and tensile deformation mechanisms of selective electron beam melted Ni3Al-based alloy at room and elevated temperatures

Selective electron beam melting (SEBM) was used to process crack-free Ni3Al-based IC21 alloy (low density superalloy) containing ~85% γ′-volume fraction. There are distinct differences between dendrites and inter-dendritic regions with the presence of coarse γ+γ′ eutectic secondary solidification microconstituents (Cr Mo-rich) in latter. The pronounced suggest that a significant elemental partitioning liquid solid occurred during SEBM. terminal is trapped at boundaries grains, as evidenced by films on cracked surfaces. In contrast extensive studies indicating segregation Zr B, we show unambiguously Si low point thereby enhancing susceptibility cracking produced tensile specimens extracted from samples exhibit superior properties room temperature (RT) 1000 °C. RT deformation mechanism characterised cutting γ′-phase two paired dislocations antiphase between. At °C deformation, well-developed γ/γ′ interfacial dislocation networks good agreement their promising high-temperature performance (σy = 518 ± 10 MPa, σUTS 560 16 20.5% for ductility).