Precision parts machining: CNC machining surface roughness and its three influencing factors
CNC machining surface geometric characteristics include several aspects of surface roughness, surface waviness, and surface machining texture. Surface roughness is the basic unit constituting the geometric characteristics of the machined surface. When processing the surface of the workpiece with metal cutting tools, the surface roughness is mainly affected by the role and influence of geometric factors, physical factors and CNC machining process factors in three aspects.
(1) Geometric factors
From the geometric point of view, the shape and geometric angle of the tool, especially the radius of the tool tip arc, the main deviation angle, the sub-deviation angle and the amount of feed in the cutting dosage, etc. have a greater impact on the surface roughness.
(2) Physical factors
Considering the physical substance of the cutting process, the cutting edge rounding of the tool and the extrusion and friction behind make the metal material plastic deformation, which seriously deteriorates the surface roughness. In the CNC lathe processing plastic materials and the formation of ribbon chips, the chip accumulation tumor with high hardness is easily formed on the front tool face. It can replace the front tool face and cutting edge for cutting, so that the geometric angle of the tool and the back eat tool amount are changed. The profile of the chipformer is very irregular, thus causing the surface of the workpiece to have tool marks of varying depth and width. Some of them are embedded in the workpiece surface, which increases the surface roughness. The vibration during the cutting process increases the value of the surface roughness parameter of the workpiece.
(3) Process factors
From the perspective of the process to consider its impact on the surface roughness of hardware parts processing, mainly with the cutting tool-related factors, factors related to the material of the workpiece and factors related to CNC machining conditions