A variety of composite materials machining characteristics
First, glass fiber reinforced plastic
FRP glass fiber reinforced thermosetting resin matrix composite materials, commonly known as, is a hard-to-cut materials. FRP are phenolic resin-based, epoxy resin-based unsaturated polyester resin matrix, such as. Glass fiber filler is the main component of SiO2, hard wear-resistant, high strength, heat-resistant than the plastic wood filler for poor may be cut. Different resin matrix can be no cutting of the same. Than the phenolic resin-based epoxy resin-based hard-to-cut. Test proved that the cutting tool material of glass fiber reinforced plastic to wear the most serious high-speed steel, P-type and M-type carbide wear is also great to wear the smallest K-type. K-type amount of cobalt used in the K10 at least the most wear-resistant, and the use of diamond or cubic boron nitride cutting tool glass steel, can enhance the production efficiency. Choice of tool geometric parameters on the high content of glass fiber glass fiber reinforced plastic sheet, molded materials and winding materials, so that r0 = 20 ~ 25 ; of filament-wound materials, so that r0 = 20 ~ 30 . Glass fiber reinforced plastic as a result of greater resilience, the latter to choose the large value of angle, so that a0 = 8 ~ 14 ; Vice smaller angle, which reduces surface roughness, fine car for the 6 ~ 8กใ. Delamination easy processing, raising the volume of glass filament-wound pipe and steel, should be 6 ~ 15 blade angle. Cutting v = 40 ~ 100m/min, f = 0.1 ~ 0.5mm / r, aP = 0.5 ~ 3.5mm, fine when aP = 0.05 ~ 0.2mm.
Second, thermoplastic resin-based composite materials
Thermoplastic resin-based composite material of the basic processing of machining features are:
1) processing time of coolant in order to avoid overheating, overheating will melt the workpiece;
2) the use of high-speed cutting;
3) The cutting tool must be of sufficient capacity trough Chip;
4) Use a small knife on the back to eat and feed small;
5) tools should be ground into a certain angle to minimize the cutting force and thrust cutting tool;
6) the application of thermoplastic composites twist drill;
7) It should be tungsten carbide or diamond tools, or special high-speed steel cutting tools with plastic;
8) the workpiece should be properly supported (it is the back pad), so as to avoid the pressure caused by cutting stratified;
9) precision machining, it is necessary to consider the plasticity of memory and processing plant at room temperature;
10) Segment and knives should be sharp, blunt tool to increase the cutting force on the workpiece.
Third, metal matrix composites
Metal matrix composites (MMC) is characterized by the greatest good shape, one has the basic shape to meet the application requirements. However, with the application of the field of composite materials to expand, especially in MMC in the field of industrial and aerospace applications, the processing of such materials and the growing importance of finishing. Such as the United States to create a large-scale SiC / Al plates, need to cut the use of water and using a standard steel connector fixed in metal matrix composite beam, tactical missiles used in the volume percentage of 25% SiC particle reinforced 2124 aluminum matrix composites extrusion rough diamond tools must be used only after processing the application, so that resulted in the corresponding water cutting, drilling, turning, such as secondary processing.
Traditional cutting, turning, milling, grinding process in general can be used, such as MMC, but the more serious tool wear, often with the volume fraction of reinforcement and exacerbated by the increasing size. Large particles or fibers and loss of ability to resist and therefore subject to stress a stronger tool. Therefore, the number of single-fiber-reinforced MMC, often there must have a mosaic of diamond or diamond tip of the tool. For short fiber or particulate composite materials, and sometimes the use of tungsten carbide or high-speed steel tools. Reinforcement of the strength of the tool wear as well. In general the higher the strength of reinforcement, the more difficult cutting. The study found that silicon carbide whisker reinforced aluminum matrix composites of aluminum matrix composites other than the difficult-to-machine. For the majority of MMC, the use of sharp tools, the right cutting speed, a large number of cooling / lubricant and a larger amount of feed, can be very good results. In general, diamond tools and cemented carbide ceramic tool than good may be more suitable for high-speed turning. Conversely, if the use of carbide cutting tools, if the low-speed turning, the long tool life. Line cutting saws can also be used to MMC, it is generally slower and can only cut a straight line.
As a result of composite materials with traditional materials have different characteristics, so cutting of composite materials and metal materials with essentially different, it is not from the processing of traditional materials to gain experience and knowledge directly applied to composite materials processing, new ways must be Research on the performance of their processing.