RU1834759C - Method of electric erosion alloying of steel workpieces by lower melting materials - Google Patents

Abstract

Usage: the creation of surfaces with specified operational properties in the manufacture of dies and parts of 2 machines. SUMMARY OF THE INVENTION: EDM alloying of formed complex-profile surfaces is carried out with a non-profiled electrode-tool (EI), for example in the form of a plate, a bar of a bar. The dimensions of the AI should exceed the dimensions of the processed profile. Material HEY: tin, lead, zinc, aluminum, duralumin. For these materials, the average operating current is determined depending on the melting temperature of the material, and the duration of the current pulses is set to more than 500 μs. The process is carried out with the direct polarity of turning ON and the part. Alloying is ensured due to maximum wear of EI and the transfer of its material in liquid form to the surface being treated with zero removal of metal from it. When worn, AE acquires the geometry of the machined profile. And w-

Description

The invention relates to electrophysical and electrochemical processing methods and may find application in the machine-building industry in the manufacture of dies and machine parts.

The aim of the invention is to expand technological capabilities when alloying complex profile surfaces of forming tools and machine parts by transferring material of the electrode-tool, which has a simple shape.

The goal is achieved. that electroerosive alloying (EEL) is carried out by electrode electrodes made of metals and alloys having a melting point Tm of several hundred degrees, with direct polarity with a pulse duration of more than 500 μs and an average current Icp, determined by the formula

Icp (0.3 ... 0.5) Mp0 8

The fundamental essence of the method is as follows. When EEL using electrodes-tools and modes that determine the maximum wear of the electrode-tool with zero removal of metal from the workpiece. In this regard, for EEL according to the proposed

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the method is supplied with a workpiece with finally machined work surfaces. As a tool electrode, for example, a plate covering the entire working surface of the work piece to be processed is used. The electrode-tool acquires the geometry of the workpiece surface as it wears out, as a result of which the EEL process covers all parts of this surface. Due to the intensive wear of the tool electrode, its material is transferred to the workpiece surface, which leads to significant changes in the operational properties of the workpiece.

Thus, the proposed method of electroerosive alloying provides the following advantages:

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ensuring its transfer to the surface to be treated in the liquid state under various conditions of the EEL process. The experimentally established relationship between the average current Cp and the melting temperature Tm of metals such as tin, lead, zinc, aluminum, duralumin is expressed as the following formula

1av (0.3 „.0.5) Tm ° -6

In this case, the greatest transfer of material of the electrode-tool is observed when the direct polarity and duration of the IM pulse is more than 500 μs. Using a pulse duration of less than 500 microseconds reduces the thickness of the heat affected zone. When using the average current Icp less than the minimum value calculated from the above expression, shape distortion is observed

1. EEL does not require a complex 2.0 machined cavity or hole with

file electrode tool. As an electrode-tool, a plate, a rod, a bar can be used, which reduces the cost of alloying.

2. In connection with the simple form of the electrode-tool it is possible, it is advisable to saturate the surface to be treated with all available elements that contribute to the increase of the part durability and are included in the composition of the electrode-tool.

The high efficiency of the change in operational properties is observed while ensuring the transfer of the material of the electrode-tool in a liquid state, in which the porosity of the surface layer is significantly reduced.

During the EEL process, tool electrodes of tin, lead, zinc, aluminum, duralumin are intensively worn out under appropriate processing conditions. The listed materials have different properties, which affects the operational characteristics of the workpieces. For example, the surface of a steel part acquires increased heat resistance with an EEL electrode-tool made of aluminum, duralumin, and the friction coefficient is reduced when using lead, etc.

The listed materials of the tool electrodes have different melting points Tm /, which requires

Compiled by N.Foteev Tehred M. Morgenthal

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Editor

using an electrode-tool of simple geometry. In the range of average currents calculated according to the above formula, the electrode tool wears out intensively, with minimal metal removal from the workpiece during the EEL process, which leads to the successful implementation of the method. At an average current exceeding the maximum value determined by the above formula, the treated surface becomes rough, unsuitable for the operation of many types of parts.

Claims (1)

SUMMARY OF THE INVENTION A method for electroerosive alloying of steel parts with more fusible materials, which is carried out with a direct polarization of the tool electrode and the part and pulse duration of more than 500 μs, characterized in that, in order to expand technological capabilities when alloying complex profiles, they use non-profiled tool electrode, the dimensions of which exceed the dimensions of the processed profile, the material of the electrode tool is selected from the series: tin, lead, zinc, aluminum, duralumin, and the current value is determined from the expression Icp (0.3, .. 0.5) Tm0 8, where Icp is the average current, A; Mp is the melting temperature of the material of the electrode-tool. Proofreader O. Kravtsovz 0 5 ensuring its transfer to the surface to be treated in the liquid state under various conditions of the EEL process. The experimentally established relationship between the average current Cp and the melting temperature Tm of metals such as tin, lead, zinc, aluminum, duralumin is expressed as the following formula 1av (0.3 „.0.5) Tm ° -6 In this case, the greatest transfer of material of the electrode-tool is observed when the direct polarity and duration of the IM pulse is more than 500 μs. Using a pulse duration of less than 500 microseconds reduces the thickness of the heat affected zone. When using the average current Icp less than the minimum value calculated from the above expression, shape distortion is observed 0 cavity or hole to be treated at Foteev ntal 5 0 5 0 5 0 using an electrode-tool of simple geometry. In the range of average currents calculated according to the above formula, the electrode tool wears out intensively, with minimal metal removal from the workpiece during the EEL process, which leads to the successful implementation of the method. At an average current exceeding the maximum value determined by the above formula, the treated surface becomes rough, unsuitable for the operation of many types of parts. SUMMARY OF THE INVENTION A method for electroerosive alloying of steel parts with more fusible materials, which is carried out with a direct polarization of the tool electrode and the part and pulse duration of more than 500 μs, characterized in that, in order to expand technological capabilities when alloying complex profiles, they use non-profiled tool electrode, the dimensions of which exceed the dimensions of the processed profile, the material of the electrode tool is selected from the series: tin, lead, zinc, aluminum, duralumin, and the current value is determined from the expression Icp (0.3, .. 0.5) Tm0 8, where Icp is the average current, A; Mp is the melting temperature of the material of the electrode-tool. Proofreader O. Kravtsovz