Exterior surface roughness is to measure one of important signs that already machined exterior quality, its wearability to the spare parts, corrosion resistance, fatigue intensity and cooperate property to have very big effect. But, in treatment influencing factor of exterior surface roughness has a lot of, to achieve good exterior surface roughness, we understand these elements what to have. One, the reason with treatment rough surface 1, rudimental area: Rudimental area is cutting tool advocate, after cutting of deputy cutting blade, remain already was machining the apparently a few areas that had be notted cut. 2, scale thorn: When using data of low speed of high-speed steel cutting tool or metal of plasticity of middling speed cutting, wait like mild steel, medium carbon steel, stainless steel, aluminium alloy, already often machining apparently the burr that produces piscine scale record, call scale thorn. Occurrence scale thorn can increase to already machined exterior surface roughness of the surface significantly. 3, the tumour that accumulate bits: In cutting process, when generation accumulates bits tumour, its can replace cutting blade outstandingly to cut work partly, already machining apparently the channel grain with lay off differ depth; When the tumour that accumulate bits falls off, conglutinate of fragment of tumour of partial accumulating bits already was being machined apparently, form petty burr, cause exterior surface roughness to increase. 4, oscillatory: When cutting is machined, because machining complex produces periodic vibration, make already machined exterior occurrence striation or moire trace, make the value increases exterior surface roughness apparently. 2, the element with the element every thorn of the rudimental area, tumour that accumulate bits, scale, oscillatory influence that affects exterior surface roughness affects treatment surface surface roughness. 1, cutting dosage: Feed is the biggest to the influence of rudimental area. Feed is reduced, rudimental area is reduced. When cutting plasticity metal, when cutting when very low or rate is very high, exterior surface roughness is worth lesser. Because bits tumour is accumulated to arise not easily when low speed,this is; When cutting rate is higher, plasticity is out of shape reduce, can eliminate the generation that scale pricks. When cutting brittleness material, the influence of cutting speed is minor, be out of shape because of material small, the value also reduces reason surface surface roughness. 2, parameter of cutting tool geometry: The radius of circular arc of point of a knife of cutting tool, tool cutting edge angle and deputy slant horn has bigger effect to rudimental area and vibration. Increase when radius of circular arc of point of a knife commonly, tool cutting edge angle and deputy slant when horn is reduced, exterior surface roughness is worth small, but if machine tool stiffness is low, radius of circular arc of point of a knife passes big or tool cutting edge angle is too small, because cutting force increases and the meeting produces vibration, make the value increases exterior surface roughness. 3, cutting tool material: Cutting tool material is different, the size of radius of point circular arc and the time that keep sharp are different. High-speed steel cutting tool can blade is ground very tartly, but retentive time is shorter, when low speed cutting so exterior surface roughness is worth lesser. Radius of circular arc of the point after blade of hard alloy cutting tool is ground is bigger, below high rate cutting surface surface roughness is worth lesser. 4, workpiece material: When processing plasticity data, the plasticity of workpiece material is lower, hardness is taller, appear thorn of the tumour that accumulate bits, scale, cold good appearance decreases, exterior surface roughness is worth smaller. Because this high-carbon steel, medium carbon steel, shift is simple,surface roughness of the surface after steel is machined is worth smaller than mild steel, when treatment is cast-iron, because cut bits to show collapse to break model, reason falls in equal treatment condition, the exterior surface roughness with cast-iron cutting is worth bigger than steel. CNC MillingCNC Machining