This study analyses literature data to identify optimised print parameters and assesses the consolidation, microstructure, and mechanical properties of Hastelloy-X printed by laser powder bed fusion. Effects of post annealing and hot-isostatic pressing (HIP) on the microstructure and mechanical properties are also revealed. The susceptibility to the solidification cracking was evaluated on the basis the solidification gradient and freezing range obtained via the calculation of thermodynamic phase diagrams (CALPHAD). In addition, the microstructure such as precipitation and chemical segregation were predicted using CALPHAD. The distribution of solidification cracks throughout the builds was quantified for the as-built, annealed and HIP conditions. The assessment reveals the variation of crack density towards the bottom, top and free surface of solid builds. This distribution of cracks is found to be associate with the thermal gradient and effective thermal conductivity, which were estimated by analytical thermal calculations. While the annealing and HIP both can alter the as-printed microstructure thanks to recovery and recrystallisation, the internal micro-cracks and internal pores were only successfully removed by the HIP. In addition to the removal, recrystallisation and precipitation in the HIP (stronger than in annealing), resulting in optimal mechanical properties including a substantial increase in elongation from 13% to 20%, significant improvement of ultimate tensile stress from 965 MPa to 1045 MPa with moderately high yield stress thanks to precipitation.

这项研究分析了文献数据，以确定最佳的印刷参数，并评估了通过激光粉末床熔合印刷的哈氏合金-X的固结度，微观结构和机械性能。还揭示了后退火和热等静压（HIP）对组织和力学性能的影响。基于通过热力学相图（CALPHAD）的计算获得的凝固梯度和凝固范围来评估对凝固裂纹的敏感性。此外，使用CALPHAD可以预测微观结构，例如沉淀和化学偏析。针对建成，退火和HIP条件量化了整个构件中凝固裂纹的分布。评估揭示了裂纹密度向底部的变化，固体构建物的顶部和自由表面。发现裂纹的这种分布与热梯度和有效热导率有关，这是通过分析热计算来估算的。尽管退火和HIP都可以通过恢复和重结晶来改变印刷后的微观结构，但内部的微裂纹和内部的孔仅被HIP成功去除。除了在HIP中去除，重结晶和析出（比退火中强）外，还获得了最佳的机械性能，包括将伸长率从13％大幅提高到20％，并将极限拉伸应力从965 MPa显着提高到1045 MPa。由于降水，中等适度的屈服应力。发现裂纹的这种分布与热梯度和有效热导率有关，这是通过分析热计算来估算的。尽管退火和HIP都可以通过恢复和重结晶来改变印刷后的微观结构，但内部的微裂纹和内部的孔隙只有通过HIP才能成功去除。除了在HIP中去除，重结晶和析出（比退火中强）外，还获得了最佳的机械性能，包括将伸长率从13％大幅提高到20％，并将极限拉伸应力从965 MPa显着提高到1045 MPa。由于降水，中等适度的屈服应力。发现裂纹的这种分布与热梯度和有效热导率有关，这是通过分析热计算来估算的。尽管退火和HIP都可以通过恢复和重结晶来改变印刷后的微观结构，但内部的微裂纹和内部的孔仅被HIP成功去除。除了在HIP中去除，重结晶和析出（比退火中强）外，还获得了最佳的机械性能，包括将伸长率从13％大幅提高到20％，并将极限拉伸应力从965 MPa显着提高到1045 MPa。由于降水，中等适度的屈服应力。尽管退火和HIP都可以通过恢复和重结晶来改变印刷后的微观结构，但内部的微裂纹和内部的孔隙只有通过HIP才能成功去除。除了在HIP中去除，重结晶和析出（比退火中强）外，还获得了最佳的机械性能，包括将伸长率从13％大幅提高到20％，并将极限拉伸应力从965 MPa显着提高到1045 MPa。由于降水，中等适度的屈服应力。尽管退火和HIP都可以通过恢复和重结晶来改变印刷后的微观结构，但内部的微裂纹和内部的孔隙只有通过HIP才能成功去除。除了在HIP中去除，重结晶和析出（比退火中强）外，还获得了最佳的机械性能，包括将伸长率从13％大幅提高到20％，并将极限拉伸应力从965 MPa显着提高到1045 MPa。由于降水，中等适度的屈服应力。