What are the factors that affect the surface roughness of CNC machining

The geometric characteristics of CNC machining surfaces include surface roughness, surface waviness, and surface texture. Surface roughness is the fundamental unit that constitutes the geometric features of the machined surface.

When using metal cutting tools to process the surface of workpieces, the surface roughness is mainly influenced by three factors: geometric factors, physical factors, and mechanical processing technology factors.
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1. Geometric factors:
From a geometric perspective, the shape and geometric angle of the cutting tool, especially the radius of the tool tip arc, the main deviation angle, the secondary deviation angle, and the feed rate in the cutting parameters, have a significant impact on surface roughness.

2. Physical factors:
From the physical essence of the cutting process, the rounded corners of the cutting edge and the subsequent extrusion and friction cause plastic deformation of the metal material, seriously deteriorating the surface roughness. When processing plastic materials to form banded chips, it is easy to form high hardness chip deposits on the front cutting surface.

It can replace the front face and cutting edge for cutting, causing changes in the geometric angle and back feed of the tool. The contour of the debris accumulation is very irregular, resulting in knife marks on the surface of the workpiece that constantly change in depth and width. Some accumulated chips are embedded on the surface of the workpiece, which further increases the surface roughness. The vibration during cutting processing increases the surface roughness parameter value of the workpiece.

3. Process factors:
From the perspective of technology, its impact on the surface roughness of the workpiece mainly includes factors related to cutting tools, workpiece materials, and processing conditions.