由图可以看出，两种激光器成形的熔覆层宽高比随着离焦量的增大而增大，即熔覆层更加平整。但使用多模激光器成形的熔覆层的宽高比要远大于单模激光器成形的熔覆层的宽高比。由前文的宏观形貌也可以看到这一特点，即单模激光器成形的熔覆层远要比多模激光器成形的熔覆层立体。因此，多模激光器更适合对零件进行局部修复或表面性能加强的二维增材成形，而单模激光器更适合用于小尺寸零件的三维立体增材制造。

As can be seen from the figure, the aspect ratio of the clad layer formed by both lasers increases with the increase of defocusing, i.e., the clad layer is more flat. However, the aspect ratio of the clad layer formed with the multimode laser is much larger than that of the clad layer formed with the single-mode laser. This feature can also be seen in the macroscopic view in the previous section, i.e., the layer formed by a single-mode laser is much more three-dimensional than the layer formed by a multimode laser. Therefore, multimode lasers are more suitable for two-dimensional additive manufacturing of parts for local repair or surface property enhancement, while single-mode lasers are more suitable for three-dimensional additive manufacturing of small-sized parts.