3D打印镍基高温合金研究进展

Research Progress of Nickel-based Superalloys for 3D Printing

金属3D打印技术依照三维模型进行复杂几何形状构件的制造,可以制造传统制造手段无法实现的复杂结构,已经成为复杂高温合金构件成形的重要技术手段。然而,当采用3D打印工艺制备镍基高温合金构件时,存在原料/能量源/熔池之间的相互作用,并在大温度梯度、极快冷等条件下会进行非平衡凝固,这些特殊的过程决定了3D打印镍基高温合金有着不均匀的微观组织与各向异性的力学性能。现阶段,对增材镍基高温合金微观结构-性能-使役行为的理解比较欠缺,严重限制了其在工业领域的广泛应用。本文讨论了3D打印镍基高温合金的特点;归纳了不同制粉方式、粒径比、粉末成分、缺陷、流动性等粉末原材料特性对3D打印镍基高温合金冶金质量的影响;梳理了3D打印激光能量、扫描速度、扫描间距等工艺参数对镍基高温合金晶粒、析出相及偏析等微观组织的影响;讨论了影响3D打印镍基高温合金拉伸、蠕变及疲劳性能的因素。最后,总结了3D打印镍基高温合金发展过程中面临的问题及可能的对策,提出了一些值得探索的方向。

Metal 3D printing technology,which can manufacture components with complex geometric shapes based on three-dimensional models and realize structures that cannot be achieved by traditional manufacturing methods,has become an important technology for the forming of complex high-temperature alloy components.However,during the process of nickel-based superalloy components by 3D printing,there is an interaction of raw materials/energy sources/melt pool,and the process involves non-equilibrium solidification under large temperature gradients and extremely fast cooling conditions.These special processes determine the heterogeneous microstructure and anisotropic mechanical properties of 3D printed nickel-based superalloys.At this stage,the lack of understanding of the microstructure,properties,and mechanical properties of additive manufactured nickel-based superalloys has severely limited its wide application in the industrial field.In this work,the characteristics of 3D printed nickel-based superalloys were discussed.The effect of powder raw material characteristics such as powder preparation method,particle size ratio,composition,defects,and fluidity on the metallurgical quality of 3D printed nickel-based superalloys was summarized.The effect of process parameters such as laser energy,scanning speed,and scanning spacing on the microstructure characteristics of nickel-based superalloys such as grains,precipitates,and segregation was sorted out.The factors affecting the tensile,creep and fatigue properties of 3D printed nickel-based superalloys were discussed.Finally,the problems and possible countermeasures faced in 3D printed nickel-based superalloys investigation were summarized,and some directions worth exploring were proposed.