SU1579752A1 - Abrasive compound for making polishing tool - Google Patents

Abstract

The invention relates to the production of an abrasive organic-bonded tool for polishing optical materials. The purpose of the invention is to improve the accuracy of shaping optical surfaces by increasing the tool durability. The weight of the diamond abrasive tool contains abrasive and binder (pitch and pulverbakelite) in the following ratio of components wt.%: Abrasive 90 - 95, pitch 4.5 - 8.5 pulverbakelite 0.5 - 1.5, and the mass ratio of pitch and pulverbakelit choose, based on the words 16 ≥ (MN: M NB) ≥ 3,3, where MN is the mass of the pitch

M NB - the mass of pulverbakelita. 1 tab.

Description

one

(21) 4469712 / 40-08

(22) 06/22/88

(46) 23.07.90. Bylo No. 27 (72) Y. DoFilatov, B0V “Rogov, NoDoRublev, I.VoDrakin, V.MoAltshuller, V.PoKorovkin and NoLoKudrtseva

(53) 621.922.079 (088.8)

(56) USSR author's certificate No. 430996, - cl. В 24 D 3/04, 19710

(54) ABRASIVE MASS FOR MANUFACTURING POLISHING TOOLS

(57) The invention relates to the production of an abrasive tool on an organic binder for polishing

optical materials. The purpose of the invention is to improve the accuracy of shaping optical surfaces by increasing the wear resistance of the tool. The diamond abrasive tool contains an abrasive and a binder (pitch and pulverbakelite) in the following ratio of wt.%: Abrasive 90-95, pitch 4.5-8 , 5 pulverbakelite 0.5-1.5, moreover, the mass ratio of pitch and pulverbakelite is chosen, based on the condition 16b (Mf,:. RMnS-) 3.3, where Mn is the mass .peka; Mng is the mass of lulverbakelite. 1 tab.

This invention relates to the manufacture of an organic bonded abrasive tool for polishing optical materials.

The purpose of the invention is to improve the accuracy of forming optical surfaces by increasing the tool durability,

This goal is achieved by the fact that pulverbakelite is introduced into the abrasive mass containing abrasive and binder (pitch) in the following ratio of components, wt.%:

Abrasive peck

Pulverbakelit

90-95 4.5-8.5

0.5-1.5

moreover, the mass ratio of the pitch and pulverbakelite is chosen from the condition

,, 3, Mn5 where M p is the mass of the pitch;

Mng- - pulverbakelite mass,

Introduction to the composition of the abrasive mass of pulverbakelite in the proposed ratio allows you to reliably bind the individual grains of the abrasive and thereby ensure the achievement of the goal

When polishing optical materials (glass and core) with an instrument consisting of abrasive, pitch and other resinous compositions, under the action of constant pressure, the surface of the tool seems to spread, taking the form of the surface being treated, and its interaction with the rough polished surface at high relative velocities Their reciprocal movement is carried out as a shock, due to which it is possible to manufacture parts with high precision and purity of the polished surface. It is the same as the glass has a dependence of physical and mechanical properties of the magnitude and application rate on the (A

SP

j

with i

SL

and

The introduction of abrasive mass into the composition of the binder as an additive to pulverbakelite in the proposed ratio provides improved physical and mechanical properties and performance indicators of the tool (wear resistance, rate of change of the working surface shape) due to the formation of a new binder as a result of the combination of pitch particles and bakelite pulver

It has been found that the productivity of polishing of optical parts increases with an increase in the abrasive content of the abrasive mass of the tool; when it is reduced, the tool loses its polishing ability — it is salted (the binder does not wear out and smears the abrasive grains).

When the abrasive content increases (decreasing the binder content), the tool begins to catastrophically wear out. To ensure the highest productivity, the polishing tool must contain at least 90% abrasive. For this, the binder should be applied evenly to all abrasive grains, which is possible only after pre-dissolving it. The dissolved binder evenly covers all the abrasive grains and remains on them in the form of a thin film after evaporation of the solvent.

The new binder, when interacting with the polished surface of the optical part, wears out much more intensively than separate pitch and pulverquelite, which has a favorable effect on

at the work of the tool (the binder does not gloss over the abrasive grains, wears out simultaneously with them, ensuring a constant contact of the abrasive grains with the surface being treated)

Example. Preparing an instrument for polishing optical parts. As an abrasive, optical poli- trite is used, as a binder — wood-resin pitch, manufactured according to TU13-400-177-164-83, and pulverbakelite.

The mass for the polishing tool is prepared as follows.

Prepare weights of abrasive (polyrite) and binder (pitch and pulverbakelite). Dissolve the binder in a solvent (ethyl alcohol grade A according to GOST 17299-78). In solution of St

0

Q

five

0

five

0

five

the abrasive is added, the resulting mass is mixed in a polyethylene container with a mixer, dried at room temperature for 60-80 minutes until the solvent is completely evaporated. The drying time and temperature do not affect the quality of the tool

Converting the binder to a liquid state and uniform coating of all abrasive grains with a solution followed by evaporation of the solvent ensures uniform distribution of the binder on the abrasive grains.

From the resulting mass, we prepared hinges on one product (tablet is abrasive polishing with a diameter of 10 mm, height 3 mm). Samples are loaded into a multi-station mold, the tablets are briquetted (until it stops), pressed and thermo-processed tablets in a drying cabinet at 120 ± 20 ° C for 30 ± 5 min. From the obtained tablets, an instrument is made in the form of a flat polishing compound with a diameter of 60 mm on the end surface of which 12 tablets are fixed.

The tool was tested when polishing the flat surfaces of optical parts made of K8 glass with a diameter of 60 mm on a machine tool mod. 2SHP-200M in the following modes: spindle rotation speed of 200 rpm; 15 mm stroke length; 5 mm stroke asymmetry

The results of studies and tests are summarized in the table. From the table it follows that with the proposed abrasive mass composition (composition 2-4), the polishing performance, tool wear rate and shaping accuracy meet the requirements of the polishing tool. Tool wear rate is less and machining accuracy is higher. than the known (composition 10), which corresponds to the goal. When the composition of the mass does not correspond to the proposed one, the wear rate of the tool is large (composition 5) and and the instrument can not be considered due to the polishing defects applied to them (scratches and Lacın) on the work surface (part 1) "

Despite the fact that a positive effect is also achieved at the boundary values of the ranges, the compositions in which the quantities of the components

The binder (pitch and pulverbequelite) are simultaneously selected at the boundaries of the range, and do not allow to reach the goal. This is due to the fact that the performance of the instrument is largely determined by the ratio

one

3.3 Ј

G 16 MP &

where M p - the mass of the pitch;

M p% - the mass of pulverbakelita

With, 3 (composition 6) tool P &

The coping is not suitable for polishing (due to the low quality of the treated surface). When It --- 1b (composition 9) and MnS

the amount of pulverbakelit is clearly not enough to increase tool durability (with specified quantities of pitch and pulverbakelite) and to achieve the goal

3.3 - g 16 (compositions 7 and 8) according to &

The goal is achieved.

Tests have shown that with the proposed composition of the abrasive mass of 151579752

0

five

0

The paper has an optimal set of properties that meet the requirements for polishing optical parts. At the same time, the tool according to the proposed solution surpasses the prototype in all respects: performance, wear resistance and surface shape accuracy.

Claims (1)

Claims An abrasive mass for the manufacture of a polishing tool containing an abrasive and a pitch, characterized in that, in order to increase the tool durability, the mass additionally contains pulverbeelite in the following ratio of components, maso%: Abrasives 90-95 Pek4,5-8,5 Pulverbakelite0, 5-1.5 and the ratio of the mass of the pitch M p and 5 mass of pulverbakelite Mng-selected from the condition 3, Ј16. M P