Surface Quality
(1) a large peak current nanosecond pulse power technology
Erosion EDM metal melting and vaporization points except two. Pulse width long duration of action, likely to cause the melting process, so that the surface morphology deteriorated deteriorated layer thickening, increased stress, easy to crack. The small width to a certain value, a very short duration of action, forming the gasification process can be reduced metamorphic layer thickness, improved surface quality, internal stress is reduced to avoid cracks.
Advanced low-speed WEDM wire used in pulse power pulse width is only tens of ns, the peak current at 1 000 A or more, forming a gasification erosion, not only high efficiency, but also greatly enhance the quality of the surface.
(2) Anti-electrolysis (BS) pulse power
Low-speed wire walk WEDM using quality working fluid. Water has some electrical conductivity, even after the plasma treatment to reduce the conductivity, but there is a certain number of ions. When connected to the positive electrode of the workpiece, in the electric field, OH- ion will continue to gather on the workpiece, resulting in iron, aluminum, copper, zinc, titanium, tungsten oxidation and corrosion, and carbide materials binder - cobalt into plasma state dissolved in water, it forms a "softened layer" surface of the workpiece. Have been used to improve the resistivity measures (by the tens of kilohms? Cm up to several hundred kilohms? Cm), minimizing ion concentration, although to improve the surface quality plays a role, but still can not effectively solve the " Problems softened layer ".
Anti-electrolysis power supply is an effective technical means to solve workpiece "softened layer". Anti-electrolysis power supply with alternating pulses, the average voltage is zero, so that oscillating between OH- ion electrode wire and workpiece in the working fluid, not tend workpiece and wire, to prevent oxidation of the workpiece material.
With anti-electrolysis power supply wire electric discharge machining, the surface modification layer control in 1μm or less, to avoid precipitation of dissolved cobalt carbide materials, to ensure carbide die life.
Cutting precision
(1) multiple cutting technology
Multiple cutting technology is to improve the low-speed walk in silk WEDM precision and surface quality of the fundamental methods. It is the integration of science and design and manufacturing technology, numerical control technology, intelligent technology, pulse power technology, precision drive and control technology. Is generally formed by a cut, second cut improve accuracy, more than three times the cutting improve the surface quality. The original order to achieve high quality surface, cutting the number of times of need up to 7-9 times, only 3 to 4 times.
(2) continue to optimize the sound processing technology corner
Because of the lag in cutting corners electrode wire will cause the collapse of the corners. To improve the precision of cutting corners, the researchers took a more dynamic corner treatment strategies. Such as: changes go wire path; change processing speed (sheet); automatically adjust the water pressure; control the processing of energy and so on.
By using an integrated control strategy corner, the corner portion when roughing shape error reduced by 70% and can cut up to 5 靘 a precision fit.
(3) the use of technology to improve the flatness
Precision finishing loop is to improve the flatness of technology, is considered to be thick pieces of processing is significant.
(4) The machine structure is more sophisticated
In order to guarantee high-precision machining, the use of a number of technical measures to improve the accuracy host: ① temperature control. Using temperature cooling device, so that the machine internal temperature and water temperature the same, reducing the thermal deformation of the machine. ② linear motor. Response and high precision positioning can achieve 0.1μm equivalents of control, feed no vibration, no noise, improve discharge frequency, stable discharge, twice cutting Ry5 μm. ③ ceramic, polymer artificial granite parts, its thermal inertia 25 times larger than the cast iron, reduce the effects of temperature changes on the cutting precision. ④ fixed table, column moving structure, improve table bearing, free from flooding may affect processing and workpiece weight change. ⑤ immersion machining, reduce the thermal deformation of the workpiece. ⑥ servo motors, closed-loop wire tension control. ⑦ precision of the knife: The power supply voltage modulation on the knife. Knife accuracy up to ± 0.005 mm, no damage to the workpiece, regardless of wet and dry.