The correlation between yttria content and thermal-mechanical properties of GRX-810

In this paper, laser powder bed fusion (L-PBF) prepared GRX-810 samples with different yttria contents (from 0.3 to 1 wt%) were systematically examined. The mechanical properties and thermal properties were measured under as-built and Hot Isostatic Pressing (HIP) heat treated conditions. The results indicate that yttria content significantly affects the thermal properties of as-built L-PBF GRX-810. Higher yttria reduces thermal diffusivity and conductivity by up to 6% in of as-built samples. HIP restores thermal properties to low-yttria levels, indicating that L-PBF-induced microdefects and porosity, rather than composition, primarily cause the thermal degradation. Based on the mechanical testing results, yttria content up to 0.45% provides the most favorable strength-ductility balance in the present dataset. Higher yttria content (from 0.5 to 1%) leads to the reduction of the elongation from 27% to around 4% in the as-built samples. Following HIP, the yield strength decreases from ~ 785 MPa in the as-built state to ~ 685 MPa. The elongation increases from 4% in the as-built state to ~ 42%. HIP samples with yttria content less than 0.45% exhibit a high ductility at approximately 40% maximum elongation, while HIP samples with yttria content higher than 0.5% exhibit a moderate ductility of approximately 18% maximum elongation at failure. These thermal and mechanical performance studies provide valuable guidance for GRX-810 applications and provide a reference for further AM-ODS alloy optimization.