RU2282530C1 - Copper base metallic binder for making tool on base of super-hard materials - Google Patents

Abstract

FIELD: abrasive working systems, possibly manufacture of tools on base of super-hard materials such as diamond, boron nitride used for working metallic and ceramic articles.

SUBSTANCE: metallic binder contains copper, tin, nickel, boron, titanium, titanium hydride, aluminum at next relation of ingredients, mass %: lead, 3 - 10; nickel, 2 - 5; boron, 0.5 - 3; titanium, 2 - 12; titanium hydride, 1 -2; aluminum, 2 - 4; copper and tin at relation 10 : 1; the balance.

EFFECT: possibility for producing abrasive wheel with high grinding coefficient, increased strength in condition of absence of intensified cooling for different working types.

2 cl, 1 tbl

Description

The invention relates to the manufacture of tools based on superhard materials, such as diamond, boron nitride, namely a metal bond for the manufacture of grinding wheels, bars, segments, intended for the machining of metal and ceramic parts.

Known metal binder for the manufacture of diamond tools (AS USSR No. 1021586 B 24 D 3/06), which includes the following components, wt.%:

Chromium carbide 10 ... 18 Copper 7 ... 9 Tin 1 ... 1,5 Cobalt rest

The disadvantage of the tool made on the specified binder is the comparative high cost of the individual components, for example cobalt, high sintering temperatures mainly using vacuum, as well as the relatively quick salting and loss of cutting ability, especially in the absence of intensive cooling.

Known metal bond for the manufacture of abrasive tools (RF Patent No. 2113912 B 24 D 3/06), containing, wt.%:

Lead 3 ... 10 Nickel 5 ... 15 Boron 0.5 ... 3 Copper + Tin in a 4: 1 ratio rest

The disadvantage of this metal bond is insufficient hardness and relatively low resistance to the machining of ceramic materials with a high content of solids (quartz, agate, etc.).

The specified composition of the metal binder is the closest to the proposed composition of the metal binder and is selected as a prototype.

The objective of the invention is to expand the scope of application of a tool based on superhard materials - STM (diamond, boron nitride) - in the processing of materials with a wide range of hardness without reducing the grinding coefficient in the absence of intensive cooling.

The problem is achieved in that the copper-based binder containing copper, tin, lead, nickel, boron, additionally contains titanium, titanium hydride, aluminum in the following ratio of components, wt.%:

Lead 3 ... 10 Nickel 2 ... 5 Boron 0.5 ... 3 Titanium 2 ... 12 Titanium hydride 1 ... 2 Aluminum 2 ... 4 Copper + Tin in a 10: 1 ratio rest

The particle size of the components of the ligament should be no more than 2 microns.

Titanium hydride is introduced to improve the strength of the fastening of particles of superhard materials in a metal binder. Aluminum is introduced to lower the temperature of the onset of the exothermic reaction during sintering.

The introduction of titanium into the metal binder during sintering leads to the formation of titanium borides with high hardness and wear resistance, and titanium hydride, decomposing, forms active titanium, interacting with the surface of particles of superhard materials, enhancing their fixation in the binder through a carbide film, and also releases hydrogen , which is a good reducing agent for oxide films, which improves the stability of the system and its high mechanical strength.

A tool made on this bond has high grinding coefficient, high resistance in the absence of intensive cooling for various types of processing of granites, ceramic and metal materials, including abrasive tools on a ceramic bond. The high mechanical characteristics of the ligament also determine the use of powders of components with a particle size not exceeding 2 microns.

The manufacture of the tool on the proposed metal binder based on superhard materials is carried out by known methods of powder metallurgy.

A mixture of superhard material (diamond, boron nitride, etc.) and a metal binder in a certain ratio is poured into the mold, the mixture is cold pressed at a specific pressure of ~ 700 MPa. Then the mold is heated to a temperature of 650-700 ° C and after fixing the beginning of the temperature increase (the beginning of the exothermic reaction), hot pressing is carried out at a specific pressure of ~ 300 MPa.

Examples of bond formulations used to make grinding wheels based on boron nitride, specifically polycrystalline Elbor grade LD 630/500 for abrasive production and their properties are shown in the table. Grinding wheels on the proposed bunch and bunch prototype were tested on the operation of grinding granite with a high content of quartz. In the manufacture of the tool used components with a particle size of not more than 2 microns.

It can be seen from the experimental data that the indicated limits of the content of boron and titanium in the binder determine a wide variation in the hardness of the metal binder within 70-120 HB, which is acceptable for processing most ceramic and metal materials.

The circles on the proposed metal binder have a compressive strength value of ~ 30% higher than those on the prototype binder, which allows them to be used for processing solid materials at elevated processing conditions.

The increased mechanical characteristics of the circles on the proposed metal bond led to an increase in the grinding coefficient by ~ 20% (see table).

Going beyond the specified limits of the content of a number of components negatively affects the qualitative characteristics of the tool, namely:

- the compressive strength is reduced by 20% in the case of an increase in the content of lead, nickel, and a decrease in the content of titanium hydride;

- decreases the grinding coefficient by 15% in the case of a decrease in the content of nickel, boron, titanium.

The use of components with a particle size of more than 2 microns leads to a decrease in the grinding coefficient by 15%.

The proposed bundle is used for the manufacture of abrasive tools designed for processing ceramic, metal materials, as well as granites of various hardness.

Table Components Ligament Compositions Prototype Bundle one 2 3 four 5 Lead 10 8 6 5 3 3.0 Nickel 2 2 3 3 5 10.0 Boron 0.5 1,0 2 2 3 1,0 Titanium - Titanium hydride one one 2 2 2 - Aluminum 2 2 3 four 3 - Copper 76.8 78,2 76,4 76,4 76,4 68.8 Tin 7.7 7.8 7.6 7.6 7.6 17,2 Physical and mechanical properties of ligaments Hardness, HB 70 79 101 109 120 93 The limit of compressive strength, kg / mm ² 150 160 180 181 190 141 Impact strength, J / cm ² 65 69 70 70 71 61 Grinding coefficient 4300 4900 4600 4700 4850 4100 Note. 1. The hardness of the compressive strength, impact strength was determined according to GOST 25 / 503-80, GOST 9454-78, respectively.
2. Grinding coefficient - the ratio of the volume of the removed material to the volume of the worn part of the circle.

Claims (2)

1. Copper-based metal binder for the manufacture of tools based on superhard materials, such as diamond, boron nitride, containing copper, tin, lead, nickel, boron, characterized in that it additionally contains titanium, titanium hydride and aluminum in the following ratio of components, wt.%: Lead 3 ... 10 Nickel 2 ... 5 Boron 0.5 ... 3 Titanium 2 ... 12 Titanium hydride 1 ... 2 Aluminum 2 ... 4 Copper and Tin in 10: 1 ratio Rest 2. The metal binder according to claim 1, characterized in that the powders of the components of the binder are used, not exceeding 2 microns.