High gloss and high precision machining method

Machining surface roughness is one of the important marks to measure the quality of machined surface. It has a great influence on the wear resistance, corrosion resistance, fatigue strength and matching properties of parts. However, there are many factors affecting the surface roughness in machining. In order to achieve good surface roughness, we will learn what these factors are.

1、 The reason of rough machining surface

1. Residual area: residual area refers to the area that remains on the machined surface after cutting by the main and auxiliary cutting edges of the tool.
2. In the process of high speed machining, it is often called as stainless steel with low speed. The appearance of scale will increase the surface roughness of the machined surface significantly.
3. Scab: in the process of cutting, when a chip is formed, the protruding part can replace the cutting edge to cut into the workpiece by computer gong machining | Dongguan computer gong machining | Shenzhen computer gong machining | mechanical parts processing | Guangzhou computer gong processing. The grooves of different depths are drawn on the machined surface; when the chip accretion falls off, part of the accumulated debris adheres to the machined surface and forms Small burr will increase the surface roughness.
4. Vibration: in cutting process, due to the periodic vibration of the process system, the machined surface appears streaks or ripple marks, and the surface roughness value increases significantly.

Machining: all factors that affect the residual area, scale, scale and vibration affect the surface roughness.

1. Cutting parameters: feed rate has the greatest influence on the residual area. When the feed rate decreases, the residual area decreases.

When cutting plastic metal, when cutting speed is very low or high, the surface roughness value is small. The reason is that it is not easy to produce chip lump at low speed, and the plastic deformation decreases when cutting speed is high, which can eliminate the formation of scale. When cutting brittle materials, the influence of cutting speed is small, because the deformation of material is small, the surface roughness value also decreases.

1. Geometric parameters of tool: the radius of tool tip arc, main deflection angle and secondary deflection angle have great influence on residual area and vibration. Generally, when the radius of the tool tip arc increases and the main and secondary deflection angles decrease, the surface roughness value is small. However, if the machine tool stiffness is low, the tool tip arc radius is too large or the main deflection angle is too small, the vibration will occur due to the increase of cutting force, which will increase the surface roughness value.
2. Tool material: the size of the edge arc radius and the time to keep sharp are different with different tool materials. High speed steel cutting tools can be grinded very sharp, but the holding time is short, so the surface roughness value is small when cutting at low speed. After grinding, the radius of the edge arc is larger, and the surface roughness is smaller at high speed.
3. Workpiece material: when processing plastic materials, the lower the plasticity and the higher the hardness of the workpiece material, there will be scaling, scaling and hardening, and the surface roughness will be smaller. Therefore, the surface roughness of high carbon steel, medium carbon steel and quenched and tempered steel is smaller than that of low carbon steel. When processing cast iron, the surface roughness value of cutting cast iron is larger than that of steel because the chip is of crumbling type.