With the advancement of science and technology, the improvement of living standards, the diversification of product demand has become the norm. As far as aluminum alloy products are concerned, the original conventional processing technology can no longer meet the diversified and high standards of industrial and daily necessities. For this reason, in the field of processing of aluminum alloy parts, the precision of processing has been continuously improved with the development of manufacturing technology.
The strength of aluminum alloy and steel plate is equivalent, but the density of aluminum alloy is less than that of stainless steel, only 1/3 of stainless steel. This lightweight, strong and tough aerospace grade metal is widely used in the manufacture of industrial and daily necessities. The aluminum alloy workpiece is made by precision cutting and grinding with a CNC machine tool. The surface has been sandblasted. It is worth mentioning that the middle frame of both is made of aluminum-magnesium alloy.
Current precision and ultra-precision machining precisions range from micron to sub-micron to nanometers, and are widely used in automotive, home appliances, IT electronic information high-tech fields, and military and civilian industries. At the same time, the development of precision and ultra-precision machining technology has also promoted the rapid development of machinery, mold, hydraulics, electronics, semiconductors, optics, sensors and measurement technology and metal processing industry.
According to the processing precision, machining can be divided into general machining, precision machining and ultra-precision machining. But this limit is constantly changing with the advancement of processing technology. Today’s precision machining may be the general processing of tomorrow. The problems to be solved by precision machining are: machining accuracy, including geometrical tolerance, dimensional accuracy and surface condition; second, processing efficiency, some machining can achieve better machining accuracy, but it is difficult to achieve high machining efficiency. Precision machining includes micromachining, ultra-fine processing, finishing processing and other processing technologies. Traditional precision machining methods include abrasive belt grinding, precision cutting, honing, precision grinding and polishing.
Precision cutting, also known as diamond tool cutting (SPDT), is performed with high-precision machine tools and single crystal diamond tools. It is mainly used for precision machining of soft metals such as copper and aluminum, which are not suitable for grinding, such as magnetic drums for computers. Metal mirrors for magnetic disks and high-power lasers are 1 to 2 grades higher than general cutting precision.
Honing, the honing head consisting of oil sands is reciprocating along the surface of the workpiece under a certain pressure. The surface roughness after processing can reach Ra0.4~0.1μm, preferably to Ra0.025μm, mainly used for processing cast iron and Steel is not suitable for processing non-ferrous metals with low hardness and good toughness.
The precision grinding of the abrasive belt is to grind the workpiece with the abrasive cloth with the abrasive. It belongs to the scope of the grinding of the coated abrasive. It has the characteristics of high productivity, good surface quality and wide application range.
Polishing is a kind of micro-machining of the surface of the workpiece by mechanical, chemical and electrochemical methods. It is mainly used to reduce the surface roughness of the workpiece. Commonly used methods are: manual or mechanical polishing, ultrasonic polishing, chemical polishing, electrochemical polishing and Electrochemical mechanical composite processing.
Precision grinding and polishing through the abrasive and machining fluid between the workpiece and the tool, the workpiece and the lap are mechanically rubbed together to achieve the required size and precision of the workpiece. Precision grinding and polishing can achieve the precision and surface roughness that can not be achieved by other processing methods for metal and non-metal workpieces. The roughness of the surface to be polished Ra≤0.025μm is small, the surface quality is high, and the precision grinding equipment Simple, mainly used for the processing of flat, cylindrical surface, gear tooth surface and sealing parts with sealing requirements. It can also be used for the finishing of gauges, gauge blocks, injectors, valve bodies and valve cores.
Ultra-precision machining is the processing of extremely high shape accuracy and surface finish on ultra-precision machine tools by using the strictly constrained relative motion generated between the part and the tool. The current ultra-precision machining refers to a processing technique in which the dimensional accuracy of the machined part is higher than 0.1 μm, the surface roughness Ra is less than 0.025 μm, and the resolution and r
