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选区激光熔化制造的IN718的组织和力学性能是由IN718预合金粉末决定的。高致密度(99.8%)的4个不同制造方向的圆柱形试样被制造出来,它们的制造方向分别与扫描方向成0°,45°,45°×45°,90°。由于胞状树枝晶的定向生长,沉积试样的典型组织特征是过饱和的柱状树枝晶以及內部的Nb和Mo元素偏析。这种多样性组织不适合于对沉积试样直接进行时效处理,同时还会使得合金对于快速加热到均匀化温度的固液相线温度过于敏感。与锻造的材料相比,当沉积试样处于均匀化和时效状态时,合金能够获得一系列较好的力学性能。在沉积状态下材料的各向异性性能较弱,表现为与热处理状态相比,材料在制造方向上具有较低的杨氏模量、屈服强度和抗拉强度。这是由于晶粒保持了在凝固时形成的几何形状和晶体织构。
The texture and mechanical properties of the IN718 laser produced by the constituency are determined by the IN718 prealloyed powder. Four high-density (99.8%) cylindrical specimens were produced in four different manufacturing directions, which were oriented at 0 °, 45 °, 45 ° × 45 °, and 90 ° to the scanning direction, respectively. Due to the directional growth of cellular dendrites, the typical tissue characteristics of the deposited samples are supersaturated columnar dendrites and internal segregation of Nb and Mo elements. This diversity of organizations is not suitable for direct deposition of the sample aging treatment, but also make the alloy quickly heated to homogenization temperature solid-liquid line temperature is too sensitive. Compared with the forged material, the alloy can obtain a series of better mechanical properties when the deposited samples are in the homogenization and aging conditions. The anisotropy properties of the material in the as-deposited state are weaker, as evidenced by the lower Young’s modulus, yield strength, and tensile strength of the material in the manufacturing direction compared to the heat treated state. This is due to the fact that the grains retain the geometry and crystal texture that forms upon solidification.