From top to bottom in the vertical direction and from the center to both sides, the roughness and thickness decrease (the change in roughness and the change in size increase)
The phenomenon of decreasing roughness and thickness (increasing roughness change and size change) appears from top to bottom and from the center to both sides in the vertical direction
In the vertical direction, the roughness and thickness decrease from top to bottom and from the center to both sides (the variation of roughness and size increase).