图为熔覆层各尺寸与离焦量之间的数据趋势曲线，由图a)可以看到熔覆层的熔宽仅在（F±0.5mm）离焦范围内可以达到1mm以下的尺寸。但超过这一离焦范围，熔覆层的熔宽就增大到1~1.5mm左右。由图b)可以看出熔覆层在各离焦量位置下左右两侧的角度对称，这间接反映了环形光斑能量分布均匀。

The figure shows the data trend curve between each size of the clad layer and the out-of-focus amount. From figure a), it can be seen that the melt width of the clad layer can reach a size of less than 1 mm only in the (F±0.5 mm) out-of-focus range. However, beyond this out-of-focus range, the melt width of the clad layer increases to about 1~1.5mm. From Fig. b), it can be seen that the angle of the molten layer is symmetrical between the left and right sides at each out-of-focus position, which indirectly reflects the uniform energy distribution of the annular spot.