In most additive layer processes, the build direction is usually the Z axis. However, orienting a part to this axis may affect build time, part strength, and even total build cost.
让我们看一下典型的粉末床添加过程。根据具体图案，热源熔化或索取一层粉末。已经融化的层对将在其顶部的层起着重要作用。先前熔化的层必须足够强，以支持即将到来的层将搁置在其顶部。此外，它必须有助于从新层进行热量。
With powder bed metal additive manufacturing, heat from the laser creates brief “weld pools” when the laser moves over the metal powder. The result is that the heat often affects the layers that have been sintered earlier. The heat slightly re-melts the earlier layers, helping to connect the layers together and resulting in a strong weld.
With overhangs, part of the area below the weld pool will be unmelted metal powder and thus, less thermally conductive, so heat from the melt pool will cool more slowly, increasing the level of sintering of the surrounding powder. This means that more material could attach to the bottom surface of the overhanging region, giving a rougher surface finish as a result of the slower cooling of powder below the overhang.
Orientation options
添加剂的专家将建议突出到建造板的突出突起应具有支持。它们还将建议设计和定向一部分，以便最大限度地减少对支持的需求，因为这可以降低构建和后期处理成本。
对大型悬垂的一些建议可能包括：
–A design with tapered material to reduce supports, possibly increasing the part mass. The downside of this option is that it may require post-process machining or wire erosion.
- 悬垂悬垂至少45度，因此自我支持
反方向,所以that you can use short supports under the bottom face. This option may also reduce build time, but may increase post-process finishing.
- 零件，使其在构建板上铺设。这将减少构建高度。但是，如果您正在进行批次，它将限制可用于嵌套零件的房间。有些部件也可能更容易转过来。
Many vendors offer build preparation software that can help designers evaluate various build orientations.
Orientation of features
How you orient a part will affect the surface finish, which may an important consideration for parts with various features. Accurately produced features on parts happen most often when the features are oriented so that they are on the top surface of a part. Some refer to this as the “up-skin.” Accordingly, aspects of a part that are on the bottom tend to be known as “down-skins” are usually have less definition.
关于方向，设计师也可能想牢记给药刮水器在构建过程中施加新粉末的潜在效果。刮水器有助于在粉末床中产生压力波，因为材料被压下。部分的一些特征可以捕获刮水器，从而产生了失败的构建。旋转部件可以减少这些效果。
In summary:
— create self-supporting designs
–consider residual stress and surface finish with part orientation
- 方向也会影响构建时间和成本
- 复杂的几何形状可以复杂化部分，因为设计人员认为表面质量，细节，构建时间/成本和支持结构之间的权衡。
雷尼绍设计指导摘录的材料
Filed Under:Make Parts Fast
