The introduction of a new technology to pass through imitation, absorption, digestion, innovation this process, the theoretical study found that line the electrode zinc content in high, cutting the effect will be better, but from the non-ferrous metal processing learn terms, when more than 40% of zinc, wire electrode alpha single-phase crystallization organization into an alpha and beta of dual phase crystallization organization, then materials become too brittle and do not suit put it processed into very small diameters filaments. So ordinary brass wire electrode in common pursuit of high efficiency by cutting today restrictions in terms of the process, so that fostered other special properties of the wire electrode.
To develop and produce a new wire electrode, the first to know to become wire electrode materials have the basic characteristics, according to the research of the technology now at home and abroad, summarizes that manufacture wire electrode materials must have the following characteristics:
A, mechanical properties: in edm process process, wire electrode is to inherit a certain tension and because of the impact of the discharge cause. If the material is too low or the strength of the fracture toughness is too low, in cutting, wire electrode will jitter, eventually leading to the cutting of the surface is smooth, more even can cause a a cutting line mark. Another strength to ensure recovery of electrode wire straight degree function also have a function, the same materials have certain electrode wire the extensibility of cutting in the tilt of the workpiece have to also be beneficial.
Second, gasification characteristics: in the machining process, the heat generated by the discharge is increased, and the heat if could not through the medium of emissions in time out, again the high melting point electrode wire materials will be melted down (wire electrode application field, speak the burning wire break), so the composition of the electrode wire materials must be there will go out of the heat function.
Third, physical properties, physical properties of the electrode wire is to improve the efficiency of the key to cutting, these characteristics are through the wire electrode material foundation of composition ratio and the composition of the core materials metal nature of the decision. Because electrode wire cut in the jitter will produce instant short circuit effect, then cutting process will slow down, if this wire electrode surface metal won't because the discharge ablation off part, wire electrode and cutting between metal won't produce gap, then produced by the cutting waste flocks will not because the role of strong water and row go out when the wire electrode will burn to break, also can't cut.
Four, geometric characteristics: here said the geometry is usually refers to size accuracy and dimensional stability. The electrode wire directly determine the diameter of the workpiece surface dimension precision cutting, so the requirement of electrode wire size accuracy and stability is very important, because every time the accumulation of the processing error can be through the machine itself to adjust, and if size accuracy is not stable, the last of the cutting precision is not stable.
Five, the electrical characteristics: electrical discharge machining is to rely on the moment to cut metal corrosion discharge, the moment the shorter the spark gap, the metal surface finish cutting out the higher, so it must have required electrode wire to withstand high pulse current moment and great cutting current ability.
Now the market popular electrode SiDou is the above five kinds of characteristics of the organic combination, of course also add some other special obvious performance: such as high strength, large extensibility, etc. According to different conditions of use and the processing condition, wire electrode is divided into the following several:
A, the common brass wire electrode: this wire electrode is 2 yuan copper zinc alloy, because get the brass zinc content in the limit, it is cutting speed restriction and, with brass zinc content in increasing, the cutting speed may have a small ascension, but its ascension speed is limited.
Second, galvanized wire electrode: core material for ordinary brass, outside a layer of zinc plating, because in cutting process of zinc gasification, the wire electrode discharge will be more stable, cutting surface can compare common yellow copper wire smooth. But this wire electrode in use process common problem is off powder problems, domestic and foreign manufacturers also face.
Three, speed type coating electrode wire: core material for ordinary brass, copper coating for zinc alloy, than ordinary galvanized wire electrode thickness of the coating to thicker. This coating wire electrode faster than ordinary galvanized wire electrode cutting quicker, suitable for high efficiency of the processing.
Four, diffusion annealing type wire electrode: diffusion annealing type electrode wire core material for non-oxygenic copper, and through the diffusion annealing in outer the packet layer of copper zinc alloy, copper and zinc of ratio of 1:1, because the core material for non-oxygenic copper, surface is formed by diffusion annealing porous structure, so the wire electrode flushing effect is better than conventional wire electrode. But no oxygen copper itself tensile strength is low, in this bronze core material manufacturing into the wire electrode intensity is low, only 500 MPA, at present this wire electrode only suitable for special special machine processing.
Five, the steel calls electrode wire: core material for steel wire, plated pure copper plating surface again brass, also have direct plating brass, the electrode wire is particularly suitable for in difficult conditions on the processing, such as super thick, high Angle, multilayer, blunt water bad, graphite, monocrystalline silicon to material processing.
Six, fine type wire electrode: general electrode wire to 0.07 mm in diameter can least, asking for a small Angle α of the fine processing, and alpha Angle of diameter 0.02 0.10 mm requirements to, they choose to create this kind of tungsten molybdenum or the super fine wire electrode.
Seven, piano wire electrode: this wire electrode for core material for manufacturing piano with high carbon steel, so also called piano wire. Composition: core material for high carbon steel, brass surface coating, also have galvanize. High carbon steel wire is under way time processing and heat treatment, will reach the same strength tungsten molybdenum wire or intensity.
At present, China precision mould and mechanical precision manufacturing processing or a new type of industry, many new the use of technology is still in trying to stage. The third, four, five, six, seven in be used actually China also very rarely used, and our users often use wire electrode only yellow copper wire and galvanized wire electrode two kinds, in view of the above two kinds of electrode wire often arise in the process of the analysis of the following disconnects do, in order to guide the user used correctly.
A. The idea the error:
The actual use of the electrode wire in the process, the user or cutting teacher always thought break because electrode wire and low strength is pulled, they also think strength low electrode wire is easy to break off, when the true break line not because the strength of the electrode wire low to cause, but because the toughness of caused by inadequate.
2. Break strings essence:
Discharge, wire electrode surface corrosion role because discharge in surface formation lots and lots of hiding, at the same time, have also been electrode wire edm or the impact of the scraps discharge, cutting process by the formation of the small hole in the smallest stress on several of the fracture toughness shortages because fracturing, namely disconnected.
3. Wire electrode discharge machining process blunt water effect:
Water in electrical discharge machining process function is important in the process of the formation of the discharge small pit and many factors, one of the most important factors are the blunt water, blunt water has a direct effect on the electrode wire and the part of the gap between gasification characteristics, of course, is easy to flush the corrosion of the waste generated crumbs row to go, and at the same time can take away in discharge the heat generated in the process.
Four. Cheap wire electrode problem:
At present in China use wire electrode, 95% above is to use common brass to make, and in the brass is typically 60%-65% of the copper, as in the last two years the copper price is more and more high, have the individual electrode wire bus bar manufacturing enterprise recycled waste mixed copper electrode wire bus to production, and the noise of the waste copper containing iron, nickel often, tin, and lead, reduce the performance of the electrode wire detrimental impurities ingredients, the existence of the impurity element is a cause of electrode wire to break for hand, in this case, users are to reduce the cutting speed to reduce break line, more even some users think is machine performance changes or cutting of the master skill is not enough. Use the electrode wire containing impurities elements not only reduces the processing efficiency, increase the cost and will also cause cutting machining quality or damage the customer of machine tools.
To sum up, in the choice to use wire electrode, the first to model from the aspects, see this is suitable for use in what types of wire electrode; Next, want to consider processing conditions, such as the material to be processed is hard or soft, surface quality requirements, processing components to the precision requirement to choose how and machine tool supporting the quality condition how to, etc. Of course, consider the quality of the water quality; Once again to consider your machine tool equipment is often is full load operation; The last to consider all sorts of different electrode wire difference between the performance.
