图 分别为正离焦范围内和负离焦范围内的熔覆层宏观形貌，增大聚焦光斑的离焦量值，熔覆层的熔宽增大，熔高逐渐减小。在相同离焦量下，负离焦光斑成形的熔覆层比正离焦光斑成形的熔覆层更加立体，熔覆层的熔宽更小。同时，负离焦光斑成形的熔覆层比正离焦光斑成形的熔覆层更加光滑，粗糙度更小。

The figure shows the macroscopic morphology of the clad layer in the positive and negative defocusing range, respectively, and the melt width of the clad layer increases and the melt height gradually decreases by increasing the defocusing value of the focused spot. At the same defocusing amount, the negative defocused spot forming layer is more three-dimensional than the positive defocused spot forming layer, and the melting width of the layer is smaller. At the same time, the clad layer formed by negative defocusing spot is smoother and has less roughness than the clad layer formed by positive defocusing spot.