The Ni-based Hastelloy X (HX) superalloy is widely used in aero-engine components because of its exceptional high-temperature strength and oxidation resistance. Given the complex structure of such parts, additive manufacturing (AM) technologies such as laser powder bed fusion (LPBF) are employed to manufacture these components. HX alloy suffers from crack susceptibility during the LPBF process, however. In this paper, this issue was addressed by adding 2 wt% submicrometer TiB₂ powder through a high-speed mixing process. Both the low-angle grain boundaries (LAGBs) and high-angle grain boundaries (HAGBs) were noted to have increased in the as-fabricated HX-2 wt.% TiB₂ composite, with an average grain size reduction from 14 μm to 8.69 μm. In addition, compared with pure HX, the hardness of the HX-2 wt.% TiB₂ composite was increased by 43.4% and 50.8% at room-temperature and high-temperature (850 °C) conditions, respectively. This indicates that the added TiB₂ reinforcement was more influential to the mechanical property enhancement under high-temperature compared to the room temperature conditions. The composite sample also showed a 28% increase in yield strength while the ductility was not found to be sacrificed compared to the as-fabricated pure HX, indicating that an addition of specific ceramic particles with suitable content may offer a new method for manufacturing crack-free high-strength and high-toughness HX alloy through the AM process. These findings also provide a reference for improving the properties of other advanced materials made by the LPBF process.

镍基哈斯特洛伊X（HX）超级合金由于其卓越的高温强度和抗氧化性而被广泛用于航空发动机部件。考虑到此类零件的复杂结构，可采用增材制造（AM）技术（例如激光粉末床熔合（LPBF））来制造这些组件。然而，HX合金在LPBF过程中易产生裂纹。在本文中，通过高速混合过程添加2 wt％的亚微米TiB ₂粉末来解决此问题。注意到在制成的HX-2 wt。％TiB _2中，低角度晶界（LAGBs）和高角度晶界（HAGBs）均增加了。复合材料，平均晶粒尺寸从14μm减小到8.69μm。另外，与纯HX相比，在室温和高温（850℃）条件下，HX-2重量％TiB ₂复合材料的硬度分别增加了43.4％和50.8％。这表明添加的TiB ₂与室温条件相比，增强对高温下的机械性能增强有更大的影响。与制成的纯HX相比，复合材料样品还显示出屈服强度提高了28％，而延展性未受到损害，这表明添加适当含量的特定陶瓷颗粒可能为制造裂纹提供了新的方法。通过增材制造工艺可生产出高强度高韧性的HX合金。这些发现也为改进LPBF工艺制得的其他先进材料的性能提供了参考。