RU1812015C - Method for contact-erosion profiling of diamond grinding wheels - Google Patents

Abstract

Usage: profiling diamond wheels on metal bonds, SUMMARY OF THE INVENTION: sequential grinding is carried out with a diamond wheel of tool electrodes made of copper and a material with higher hardness and wear resistance than the bonding material of a circle, for example, T15K6 alloy. The circle and electrodes are connected to a source of technological current (direct polarity). At the last stage of processing, after the formation of the required profile of the circle, grinding of the second electrode is carried out by changing the polarity of the circle and electrode to the opposite. This leads to hardening of the surface bond layer and provides increased durability of its profile.

Description

The invention relates to electrical discharge machining and, in particular, to contact-erosion formation of the surfaces of diamond circles on metal bonds.

The purpose of the invention is to increase the durability of the profile of the circle when grinding products due to the hardening of the surface bond layer.

The method is implemented as follows.

First, two cathode electrodes, respectively, of copper and a material with a higher hardness than the bonding material of the wheel, are ground in succession with a diamond wheel - anode. A copper electrode allows high productivity of forming a desired profile on a circle. Grinding the second electrode helps to remove loose and excessively protruding diamond grains from the bond and forming a circle profile with diamond grains with a higher bond strength

Then, at the last stage of processing (upon completion of the formation of the required profile of the circle), grinding of the second electrode is carried out by changing the polarity of the circle and electrode to the opposite. This leads to doping of the surface bonding layer with the electrode material due to chip closures accompanied by electrical discharges.

The criterion for evaluating the end of grinding at the last stage may be the beginning of a monotonic increase in the strength of the working current. An increase in the current strength indicates an increase in the thickness of the layer of electrode material deposited on the bond surface, and continued processing can lead to overgrowing of diamond grains and a decrease in the cutting ability of the wheel.

Example. The effectiveness of the method was investigated on a modernized universal grinding tool Model 3-M642E, equipped with a constant current source of 1.5 kW with adjustable

with

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the output voltage in the range 0-36 V. Diamond blades of type 1A1 200x20x3x32 AC6 80/63 M1 were machined 100%, it was required to obtain a multi-thread threaded profile with a depth of 1.5 mm. As a coolant, a 0.5% aqueous solution of soda ash was used, which was fed into the irrigation treatment zone at a flow rate of 1.5 l / min.

At first, at a straight polarity, a shaped electrode with an equidistant profile was formed, a disk electrode made of M1 copper, under the following technological conditions: rotation frequency of the diamond wheel pKr 2240 rpm, circular feed electrode pel 1/80 rpm, grinding depth .5 mm, the initial voltage of the source (no load) UH 25 V, the operating voltage Up 15-25 V, the strength of the operating current I 20-ZA. Then, having obtained a preliminary profile on the wheel, we polished the second shaped disk electrode from the T15K6 alloy at t 0.06 mm (the polarity, Pcr, Pel, and UH were the same).

Then, at the end of the formation of the required profile on the wheel, the polarity of the circle and the electrode of the T15K6 alloy was reversed and polished at pcr 2240 rpm, Pel 1/40 rpm, t - 0.005 mm. UH, I 10A. As a result, alloying of the surface bond layer with the electrode material and increase in the resistance of the diamond wheel profile during grinding of ferrite products by 1.2-1.4 times were achieved.

Claims (1)

SUMMARY OF THE INVENTION A method for contacting and erosively forming surfaces of diamond circles on metal bonds, comprising grinding with a diamond wheel electrode-tools made of copper and a material with higher hardness and wear resistance than the material of the bond of the circle, by connecting the circle and electrodes to a technological current source, characterized the fact that, in order to increase the resistance of the profile of the circle when grinding products due to the hardening of the surface bond layer, grinding the electrode from a harder material on the last The first stage of processing is carried out when the polarity of the circle and electrode is reversed.