The process of forming machined surfaces
Machined surfaces are achieved through the cutting action of a mechanical CNC machining process. During the machining process, the tool removes excess material from the workpiece to form the desired cutting grain surface. The process of forming machined surfaces involves machining methods such as turning, milling, grinding, and drilling.
Cutting motion and workpiece surface formation
In machining, the cutting motion is the key to directing the surface of the workpiece. The cutting path usually consists of a main motion and a feed motion.
The main motion is the primary movement of the tool against the workpiece, such as rotary motion in a lathe or linear motion in a milling machine. The feed motion is the additional motion of the tool against the workpiece and determines the depth of cut and the cutting path.
The role of the tool
The shape and movement of the tool directly affects the formation of the workpiece surface. The cutting edge of the tool comes into contact with the workpiece material and removes it by cutting. The geometrical parameters of the tool (e.g. front angle, back angle, main deflection, etc.) and the material properties (e.g. hardness, toughness) together determine the characteristics of the cutting process and the roughness of the workpiece surface.
Workpiece material response
The material undergoes plastic deformation and fracture during cutting. The distribution of cutting forces and heat affects the flow and removal of material and the formation of surfaces. Work hardening, residual stresses and microstructural changes are all a result of the material response during the cutting process and these changes affect the final properties of the workpiece.
Control of surface quality
Geometrical characteristics of the workpiece surface such as surface roughness, corrugation and grain direction, as well as the physical and chemical properties of the surface layer, affect the functionality and durability of the part. The quality of the workpiece surface can be effectively controlled and improved by adjusting the cutting parameters, selecting suitable tools and adopting advanced CNC machining technology.
Customised tool pattern
By editing the machining programme through CRM software, the tool is allowed to move according to the designed pattern to achieve the final desired pattern effect.
Conclusion
The formation of machined surfaces is a complex physical and mechanical process involving the interaction of tools, workpiece materials and machining parameters. By accurately controlling these factors, workpieces with the desired size, shape and surface quality can be produced.
