SU1046058A1 - Method of combined machining - Google Patents

Description

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The invention relates to a combination treatment combining mechanical electrical treatment with coating and can be used in the processing of aluminum and magnesium alloys. The closest to the present invention is the method of honing and coating by successively carrying out preliminary honing operations with a tool containing a unclenching needle and abrasive sticks, electrolytic coating with simultaneous abrasive effect and, finally, honing. However, the known method, differing in high productivity (30 µC / min), does not provide high surface quality due to the fact that aluminum belongs to a group of very negative α-metals, and chromium in a passive state, on the contrary, becomes much more positive. The aim of the invention is to improve the quality of the surface when machining aluminum and magnesium alloys with chromium plating. This goal is achieved by the fact that, according to the method including honing operations, coating (chrome plating) and finally honing, before the operation of applying chromium to the surface, a copper sublayer is applied frictionally, for which the process is conducted with a tool with copper bars located above the abrasive and coaxially with them. FIG. 1 shows a device for carrying out the proposed method; in fig. 2 is a section A-A in FIG. 1; Fig. 3, section B-B in Fig. 1; In the electrically conductive body 1 of the honing head, needles 2, 3 are placed, which cooperate with abrasive bars C and bars 5 of copper alloy. The device is equipped with an electrolyte supply system 6 and an electric power supply source 7. Radial holes 8 are made between the copper bars. Abrasive bars relative to the surface of the product 9 are spring-loaded in the radial direction spring 10. The work is carried out as follows. At the first stage of processing, the power supply 7 is disconnected. The supply system of the electrolyte 6 is also disabled. Spindle rotation is switched on at a speed of 200 rpm while lowering the honing head into the cavity of the product 9. Contact bars with the product 9 enter the decorative bars 4,. Manufacture honing of the internal surface of the product. Using a tapered needle 2, the pressure L is reported to give a pressure of 0.7 MPa. The speed of the reciprocating movement of the bars is 0.33 m / s. Honing duration p. At the end of the process, the abrasive bars 4 are removed from the treatment area. Bars 5 from a copper-based alloy are fed to the treatment area. The sliding speed of the bars O, 15 m / s, the specific pressure transmitted by the additional needle of unclamp 3, is 60 MFla. Y50 rev / min rotation speed Through the holes 8 between the bars 5, it is fed to the treatment zone of the alcohol-glycerol mixture. The process of frictional deposition of a layer of copper-containing alloy on the inner surface of product E is carried out. The thickness of the applied layer is 5 microns. At the end of the friction process, deposition of a sublayer of copper-based alloy bars 5. Output from the treatment zone. An electric power source 7 and an electrolyte supply system 6 are turned on. In the treatment zone, abrasive bars are introduced. In this case, electrically conductive is the cathode, body 1 - anode. The pressure of the bars k with the help of the unclamping needle 2 is set to 0.06 MPa, Spring 10, allowing the bars to activate the chromium plating process, preventing the possibility of cutting the applied layer. The current density is 150 A / dm. A chromium plating electrolyte of universal composition is used. Deposition time 1, min. The thickness of the chromium layer 50 microns. At the end of the electroplating process, the power supply is turned off. The pressure of the bars A on the surface of the product 9 increases to 0.5 MPa, providing a surface roughness of 0.160 geometric shape and the required size. The proposed method makes it possible to increase the corrosion resistance of a chromium-plated product from aluminum and magnesium alloys by 30-35 with a labor intensity of 3-5 minutes.

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Claims (1)

METHOD OF COMBINED PROCESSING, including operations of preliminary honing with abrasive bars, applying an electrolytic coating with simultaneous abrasive action and final honing, characterized in that, in order to improve surface quality during processing and chrome plating of products from aluminum and magnesium alloys, before the chromium plating operation on frictionally treated surface is applied a copper underlayer, which over Abra _x · zivnymi bars coaxially with them a copper bars. 1 1046058