SU1659380A1 - Method of manufacturing abrasive products - Google Patents

Abstract

This invention relates to the manufacture of an ammonia-based abrasive tool, primarily for finishing materials. In order to improve processing performance and improve the cutting properties of tools, gamma alumina with a grain size of 200-250 microns is taken as the main fraction, and silicon oxide with a grain size of 60-80 microns in an amount of 1.5-2.5 is taken as an additional fraction. wt.% and the formation of products is carried out in two stages, with static and dynamic loading, the dynamic loading power is 0.5-0.65 mW / g of the weight of the pressed mixture. Thermal treatment of the abrasive product is performed at 1400-1450 ° C for 2 -3 hours

Description

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This invention relates to the manufacture of an alumina-based abrasive tool, primarily for finishing difficult-to-machine materials.

The purpose of the invention is to increase the productivity of processing and improve the cutting properties of tools.

The proposed method for making abrasive products is as follows.

Mix powder gamma-alumina with a grain size of 200-250 microns and powder of silicon oxide fraction 60-80 microns in the amount of 1.5-2.5 wt.%. Then, the charge is poured into the mold and static loading is performed, and then, without removing the static load, dynamic loading is performed by an electro-hydraulic shock wave with a specific power of 0.5-0.65 mW / g of the charge weight. Then the extruded product is removed from the mold, thermoablative at 1400-1450 ° C for 2-3 hours

Testing of the abrasive product obtained by the method described was carried out by treating steel 40X in the normalization state (HB 229) by the method of honing under the following conditions: circumferential speed m / min, axial velocity 18 m / min, specific pressing pressure 0.005 MPa.

PRI me R 1. For the manufacture of an abrasive article, a mixture of a gamma alumina fraction of 20 µm and a powder of silicon oxide of a fraction of 60 µm in an amount of 1.5% by weight is prepared. The charge is poured into the mold and a static pressing is performed to obtain a pressing density of 0.6-0.7 of the density of the finished product. Then, not removing the static load, a single dynamic loading of the electrohydraulic

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shock wave with a specific power of 0.5 mW / g of the weight of the charge. Then the product is removed from the mold, placed in an oven and heat treated at 1,400 ° C for 2 hours.

The obtained abrasive product has a compressive strength of 57 MPa; when honing in the indicated modes, the processing performance as compared with the known one is 104%, wear is 1.1 times lower.

EXAMPLE 2 For the manufacture of an abrasive article, a mixture of a gamma alumina fraction of 250 µm of a powder of silicon oxide of a fraction of 80 µm in an amount of 2.5% by weight is prepared. The charge is poured into the mold and a static pressing is performed to obtain a pressing density of 0.6-0.7 of the density of the finished product. Then, the static load is not removed, a dynamic loading is made by an electric shock shock wave with a specific power of 0.5 mW / g of the charge weight. Heat treatment is carried out at 1400 ° C for 2 hours.

The resulting abrasive product has a compressive strength of 57 MPa, when honing in these modes, the processing performance compared to the known is 105%, wear is 1.1 times lower.

EXAMPLE 3 A mixture prepared as described in Example 2 is poured into a mold and static pressed, then, without removing the static load, the shock wave with a specific power of 0.65 mW / g of the charge weight is heat treated at a temperature of 1450 ° C for 3 hours

The resulting abrasive product has a compressive strength of 58 MPa. When honed, the productivity in comparison with the known one is 107%, the wear is 1.15 times lower.

PRI me R 4. For the manufacture of an abrasive article, a mixture of gamma alumina of a fraction of 200 µm and a powder of silicon oxide of a fraction of 80 µm in an amount of 2% by weight are prepared. Pour the charge into the mold and produce a static pressing to obtain a density of pressing 0.6-0.7 of the density of the finished product.

whether. Then, not removing the static load, a single dynamic loading is made by an electro-hydraulic shock wave with a specific power of 0.55 mW / g of the weight of the charge. Then the product is removed from the mold, placed in an oven and heat treated at 1450 ° C for 2 hours.

The resulting abrasive product has a compressive strength of 56 MPa. When honing at the indicated modes, the processing performance as compared with the known one was 109%, the wear was reduced 1.1 times.

The average grain size in the product in relation to the initial one is 0.74-0.86, the isometric coefficient of the grains is 0.58-0.63. the porosity is 11.0–12.0% (for a known 11%).

When honing, the machining performance is 1200-1300 mm3 / min {at a known 1200 mm / min), tool wear is 22-28 mm / min (at a known 30 mm3 / min).

With superfinishing, the machining performance is 76-79 mm / min (67 mm / min for a known one), tool wear 11-13 mm / min (for a known 14 mm / min).

Claims (2)

1. A method of making abrasive products mainly for finishing by preparing a mixture based on alumina powder, shaping under static and dynamic loading with a shock wave followed by processing, characterized in that, in order to increase the processing performance and improve the cutting properties of tools, its gamma modification is used as alumina and silicon oxide powder is additionally introduced in an amount of 1.5-2.5 wt.%, the dynamic loading is produced by a shock wave th power 0.5-0,65 mW / z mass charge the pressing and heat treatment - at 1400-1450 ° C. 2. Method pop. 1, characterized in that alumina with a grain size of 200-250 microns and silica with a grain size of 60-80 microns is used.