SU1484517A1 - Method of spark-erosion alloying - Google Patents

Abstract

The invention relates to machining. The purpose of the invention is to increase the doping performance by acting on the interelectrode gap by a magnetic field. Doping is performed by pulsed discharges when a magnetic field is applied to the interelectrode gap with a period equal to the positive half-wave of the discharge pulse, while the attenuation is chosen so that during the discharge no less than three half-waves of the magnetic field are formed, and the mechanism of the third half-wave of the magnetic field falls on the amplitude mechanism of the reverse half-wave. 2 Il.

Description

The invention relates to electrophysical and electrochemical processing methods and relates to methods of electrospark doping.

The purpose of the invention is to increase the doping performance by influencing the magnetic field on the mass transfer processes in the interelectrode gap.

Figure 1 shows the device for implementing the method in figure 2 - current diagrams.

Electrode-tool 1 is located next to the workpiece 2. The pulse source 3 is connected to the electrode 1 and the workpiece 2. The electrode rod 1 is wound with coils 4 connected to the source 5.

The current pulse of doping 1e (Fig. 2) of source 3 has a reverse half-wave amplitude 1. The current pulse 1M of source 5 is passed through coils 4 in such a way that during the time

one half-wave of Tae arises two half-waves of the electromagnetic field T.

At the same time, the moment of supplying current 1M is shifted relative to the moment of supplying current 1E for the time Tg.

Tz is set from those considerations so that the peak of the third half-wave of the current 1c coincides with the peak of the amplitude of the reverse half-wave

The method is carried out as follows.

When a doping current of 1E occurs, the source 5 is turned on and, in turns 4, covering the electrode tool 1, a pulsed current of 1H is excited. During the period of action of the pulse 1E, the passage t two half-waves 1sh, and the maximum of the third half-wave 1 "occurs at the time of the peak of the reverse current 10

Since the magnetic field changes direction during the spark discharge, material erosion occurs

(L

four

oo

4b

cl

the electrode and the dispersion of the structural components increase, while in the particles of the transported metal and in the electrode countercurrents are induced, which in turn create their own magnetic fields. The interaction of the imposed and induced fields leads to an increase in the rate of movement of particles to the part. The high-temperature heated molten particles, combined with dissociated atomic nitrogen and atmospheric oxygen, differ in composition and properties from the original anode material and are introduced into the surface of the part. In this case, due to the magnetic field, the depth of penetration of particles and the diffusion rate increase, and due to the fact that the magnetic field changes direction during the discharge, a forced multiple displacement of the resulting phases in the coating occurs. Thus, the quality of the coating is significantly improved, and the structure of the hardened layer becomes more uniform. Positive magnitude of the magnetic field at the end of the spark

eliminates the destruction of the applied coating and the deterioration of the quality of the hardened surface, as well as prevents the back transfer of the cathode material to the anode and the destruction of the resulting coating.

Claims (1)

Claims of the Invention Electro-spark doping method using a rod electrode tool, in which a magnetic field is applied to the interelectrode gap during a pulse discharge, characterized in that, in order to improve performance, an alternating magnetic field is induced with the attenuation in order to generate at least three half-waves, and a period that generates two half-waves during the positive half-wave of the discharge and the coincidence in time of the amplitude values of the inverse the half-wave of the discharge current and the third half-wave field, while the direction of the field lines in the third half-wave is chosen opposite to the direction of the reverse half-wave current. y // t7 / t figure 1 figure 1