SU779057A1 - Mass for making abrasive tool body - Google Patents

Description

one

The invention relates to diamond abrasive production, in particular, to the composition of the mass for the manufacture of abrasive wheels on a ceramic bond from K & boron nitride, and can be used in enterprises producing tools from elbor, cubonite, etc., etc.

The working layer of grinding wheels consists of cubic boron nitride, a filler, mainly of white electrocorundum 22A-25A, and binder, and a body of one or several known abrasive materials and w-vista.

The composition of the abrasive mass is known with a thermal expansion coefficient close to the thermal expansion coefficient of the working layer of grinding wheels, consisting of a mixture of green silicon carbide (Si C) and white electrocorundum (,)

In order to increase the strength of the bond between the working layer and the tool body, silicon carbide is introduced into the mass in a volume equal to the volume of the highly hard material of the working layer,. cubic boron nitride. Mass components are taken in the following ratio, weight,%:

33.0-43.0

Silicon carbide

30.0-39.0

Electrocorundum

10.0-16.0

Frit

5.0-10.0.

Kaolin

5.0-7.0

Humidifier

Silicon carbide green is known to have a higher thermal expansion coefficient than cubic boron nitride.

10 With an equal volume of creme carbide in the body mass and cubic boron nitride in the working layer, the thermal expansion coefficient of the body of the abrasive tool will be higher,

5 than the working layer. This leads to the peeling of the working layer from the body, the appearance of cracks at their boundary and does not provide the required strength of connection of the working layer with the body of the abrasive tool. These drawbacks are especially manifested in the manufacture of abrasive tools with a shaped profile, for example L2FP type grinding wheels with a double toroidal layer of elbor, in which the boundary of the working layer with the body has a curvilinear surface, or Flat abrasive circles with a semicircular convex type K5P.

30 Eliminate these shortcomings can be

Claims (2)

Claim Thus, in the abrasive wheel, due to a decrease in the coefficient of thermal expansion of the case, the mass for the manufacture of the case of an abrasive tool with a working layer of cubic boron nitride, containing silicon carbide, electrocorundum, a ceramic bond and a humidifier, characterized in that they crack cracks at the boundary between the case and the worker, is not a problem. layer, there is no peeling of the working layer from the body, increases the strength of the abrasive wheel as a whole. This allows you to use circles of cubic boron nitride for high-speed grinding of parts. Silicon carbide powders of green and white electrocorundum are moistened with liquid bakelite, mixed with a ceramic binder and molded in molds, after which firing is performed. Two mass batches of 10 circles of the L2RP type with a double toroidal elbor layer were made. The composition of the proposed and known masses are given in the table. * that, in order to increase the bond strength of the working layer with the casing and create an interference fit in the working layer to compensate for inertial loads in the shaped profile circles, the volume of silicon carbide introduced into the mass is 1.2-1.3 times the volume of cubic boron nitride in the working layer with the following content Silicon carbide Electrocorundum Ceramic bond Component humidifier, wt.% 45-50 22-32 19-26 2.0-4.0