In this work, the microstructure, precipitations, crystal orientation and texture of an Inconel 718 superalloy manufactured by selective laser melting (SLM) are investigated by performing post heat treatment. Horizontal and vertical reference faces are examined in the as-built condition, solution conditions for 0.5 and 1 h, and aging condition, respectively. In the as-built condition, Inconel 718 superalloy exhibited cellular and columnar dendrites, a large amount of the fine Laves phase, and several γ′ phases. During post treatment, the grain size on the horizontal face is changed, which is ranged from 502.23 to 523.55 μm² per grain. Meanwhile, grains coarsened distinctly on the vertical face. The average area of the grain is 739.48 μm² in the as-built condition and increases to 898.19 μm² in the aging condition. Additionally, the amount of MC carbides, γ′, and γ″ strengthening phases increased as well during the post heat treatment process, while that of the Laves phase decreased after solution treatment. The preferred orientation on the horizontal face was 〈111〉//X, 〈001〉//Y in the as-built condition, and 〈101〉//Z in the solution and aging conditions. The preferred orientation on the vertical face was 〈001〉//X, 〈101〉//Y in the as-built condition, 〈101〉//Y in the solution condition, and 〈001〉//X in the aging condition. The orientation distribution function (ODF) analysis showed that the main textures in the as-built and solution conditions were {110}〈110〉 and {110}〈112〉, respectively, which transformed to {001}〈100〉 and {001}〈110〉 during aging. The values of multiples of uniform density (mud) in both horizontal and vertical reference faces the aforementioned preferred orientation and texture increased during post heat treatment. Application of post heat treatment can lead to an ideal microstructure Inconel 718 superalloy manufactured by SLM.

在这项工作中，通过进行后热处理研究了由选择性激光熔化 (SLM) 制造的 Inconel 718 高温合金的微观结构、析出、晶体取向和织构。水平和垂直参考面分别在竣工条件、0.5 和 1 小时的溶解条件以及老化条件下进行检查。在竣工状态下，Inconel 718 高温合金呈现出蜂窝状和柱状枝晶，大量细小的 Laves 相和几个γ相。在后处理过程中，水平面上的晶粒尺寸发生了变化，其范围为每粒 502.23 至 523.55 μ m ²。同时，垂直面上的晶粒明显变粗。晶粒的平均面积为 739.48 μm ²在建成条件下增加到898.19 μ m ²在老化条件下。此外，MC碳化物的量、γ ′和γ″ 在后热处理过程中强化相也增加，而在固溶处理后 Laves 相的强化相减少。水平面上的优选取向在竣工条件下为<111>//X，<001>//Y，在溶液和老化条件下为<101>//Z。垂直面上的优选取向为<001>//X，在建成条件下为<101>//Y，在溶液条件下为<101>//Y，在时效条件下为<001>//X . 取向分布函数（ODF）分析表明，在竣工和解决方案条件下的主要纹理分别为{110}〈110〉和{110}〈112〉，分别转化为{001}〈100〉和{001 }〈110〉在老化过程中。水平和垂直参考面中均匀密度（泥浆）的倍数值在后热处理期间增加了上述优选取向和纹理。后热处理的应用可以产生理想的微观结构 Inconel 718 高温合金由 SLM 制造。