Some important parts must work under the conditions of high speed, high temperature, high pressure and heavy load. Any defects in the surface layer not only directly affect the working performance of the parts, but also accelerate the wear, corrosion and failure of the parts. Therefore, we must pay attention to the surface quality.
What is the surface treatment of aluminum alloy processed by computer gong
(1) Geometric properties of surfaces
① Surface roughness surface roughness refers to the micro geometric error of machined surface. In Figure 5-8 (a), R. Represents the arithmetic mean deviation of the roughness profile. The surface roughness is usually formed by the movement path of cutting tool in machining, and the ratio of wavelength to wave height is generally less than 50.
② Surface waviness and surface transition are periodic geometric errors between macro geometric errors (△ *) and micro geometric errors (roughness). In Fig. 58 (b), a represents the height of waviness. The surface waviness is usually caused by the low frequency vibration of the process system in the process of machining, and the ratio of the surface waviness to the wave height is generally 50 ~ l ∞ 0.
The deviation degree of actual geometric parameters from ideal geometric parameters is called machining error. The level of machining accuracy is measured by the size of machining error. If the error is large, the accuracy will be low, otherwise it will be high.
Machining accuracy includes dimension accuracy, shape accuracy and position accuracy.
① The degree of correspondence between the actual size of the machined part surface itself or between the surfaces and the ideal part size. The ideal part size refers to the median value of the dimension marked on the part.
② The degree to which the actual shape of the machined part surface is consistent with the ideal part surface shape. The ideal part surface shape is the absolutely accurate surface geometry.
④ The position accuracy is the degree to which the actual position of each surface of the machined part is consistent with the position of each surface of the ideal part. The position between the surfaces of an ideal part refers to the absolutely accurate position between the surfaces.
The common milling machine completes the pin milling operation by calculating the feed and controlling each feeding process by parts
CNC milling machine has five elements: CNC system, detection device, driving device, transmission chain of machine tool and servo motor. It is an automatic and high-precision milling pin operation controlled by computer through human programming in advance
Numerical control milling machine batch production efficiency is high, processing consistency is good, quality is stable. But when the price is high and the number of processing is small, the programming time is more, which is not cost-effective. The advantage of CNC milling machine is to produce products in large quantities. CNC milling machine processing is relatively fast and labor-saving. What are the advantages and disadvantages of CNC machine tools compared with ordinary milling machines? The processing principles are almost the same, but the milling machines are semi-automatic, while the CNC milling machines are digital controlled, and the automatic processing is controlled by program or NC.
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