JPS5940221B2 - Sintered iron-based friction material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to powder metallurgy, particularly sintered friction materials, more specifically sintered iron-based friction materials.
Ased friction material).

The field of application of the invention is automobiles, tractors, aircraft, road construction machines, and other equipment working with liquid lubrication in intermediate operating modes and under friction (peripheral speed of friction below 9 m/s, pressure 25 kg/cyyf) , below) is a friction device used for

Sintered iron-based friction materials that work under dry friction conditions and friction with liquid lubrication are widely used.

Sintered (porous) friction materials consist of metallic and non-metallic components.

The metallic components give the material strength, and the non-metallic components increase the coefficient of friction and reduce the tendency to jam.

The properties of sintered friction materials lie in the thin surface layer created during the friction process, whose plasticity and viscosity are determined by the components that make up the material.

Compared with the base of friction material, the surface layer of friction material is more plastic at room temperature, especially at high temperature, and has a clear trend of mechanical properties in the depth direction of the material, and can effectively prevent excessive deformation. .

The plastic surface layer reduces local pressure and surface temperature and contributes to vunning in.

By grinding, the friction material has the property of increasing its actual surface as a result of wear or plastic deformation.

The surface layer of the sintered friction material is characterized by a heterogeneous texture, ie it consists of a mixture of main components and fine hard inclusions.

The hard particles present in the surface layer contribute to the wear resistance of the sintered friction material.

This is because the hard particles are conveniently located on their surface and bear most of the load under the applied force.

If the adhesion between the hard particles and the base material is weak, this will result in increased wear when the hard particles become detached at high sliding speeds and enter the friction zone.

Sintered iron-based friction material (cf, Ignator L) with the following components in weight percent: 15 parts copper, 9 parts graphite, 3 parts silicon oxide, 3 parts barium sulfate, 6 parts asbestos, and 3 parts iron.
,l.

”Proizvodstvo frictionsion
ykhmaterialov zheleznoi o
MetalluPubl 1sher
s, Moscow, 1968) is known.

The following chemical components in weight percent: Copper 9-25 Manganese 6.5-10.0 Boron nitride 6-12 Boron carbide 3-15 Silicon carbide 1-6 Molybdenum disulfide 1-5 Iron 2-5 Others with the balance Sintered iron-based friction materials (see, for example, USSR Inventor's Certificate No. 358,401) are known.

The following chemical components in weight percent: Copper 1-3 Tin 0.5-2 Barium sulfate 3-5 Graphite 4-1 Molybdenum disulfide 2-6 Nonoiro Ceram 1-3 Lead o, i-4 Iron with balance Sintered iron-based friction material (Soviet Union inventor certificate No. 3796)
No. 65) is also known.

Hard particles of silicon oxide, asbestos, boron carbide, silicon carbide, iron carbide and iron oxide present in sintered iron-based friction materials known as additives to increase the coefficient of friction form on the surface of the material subjected to friction. It causes high temperatures (below 900°C) and changes the surface layer structure of the friction material.

The structural change will reduce the strength properties.

Thus, the above-described iron-based friction materials are known to exhibit insufficient strength properties and are unable to provide adequate durability of the devices in which they are used.

Other sintered iron-based friction materials with the following components in weight percent: Copper 4-15 Nickel sulfate 2-8 Graphite 4-10 Nonoiroceram 2-10 Lead 2-8 Iron balance (Soviet inventor's certificate No. 50)
3927) is also known.

Pyroceram contained in the above sintered iron-based friction material is a base (
Since it does not have a chemical bond with iron), it weakens the overall material and reduces its wear resistance.

Furthermore, the high content of abrasive particles in the friction material makes it impossible to obtain complete contact between the material and the contacting object, which adversely affects the fit.

The main object of the present invention is to provide a sintered iron-based friction material that has increased wear resistance and improved frictional matching under liquid lubrication conditions of intermediate operating modes by appropriately selecting its components. be.

For this main purpose, a sintered iron-based friction material comprising copper, tin, graphite, pyroceram and lead, according to the invention, contains zinc sulphide in the following proportions by weight:

Copper 15-30 Tin 1.0-2.0 Zinc sulfide 2.0-4.0 Graphite 6.0-10.0 Nonoiro Ceram 2.0-5.0 Lead 10.0-20.0 Iron Balance The zinc sulfide is contained in the friction material in an amount of 2 to 4% by weight as described above.
It can improve wear resistance and running in under liquid lubrication conditions in intermediate processes.

However, a zinc sulfide content of less than 2% does not guarantee protection against scratches and bites with objects with which it comes into contact during work, and above 4% weakens the surface layer of the material.

As the zinc sulfide content increases somewhat, sulfur inclusions are found in the material, and their amount increases as the zinc sulfide content increases.

Free sulfur inclusions significantly reduce compressive and tensile forces, impact forces and hardness, thereby reducing wear resistance.

The above pyroceram is also called glass ceramic and Ca0
2B203. Al2O3,5i02. It is made of TiO2.

) The content of this pyroceram (glass ceramic) is optimally 2 to 5% by weight as shown in the claims of the present application, and if the pyroceram is less than 2%, the above-mentioned improvement in the coefficient of friction and wear resistance cannot be obtained. If the force exceeds 5%, it weakens the base of the friction material.

The sintered iron-based friction material of the composition provided has high wear resistance and good abrasion.

It is produced during the sintering process when the sulfide-forming additive zinc sulfide is completely decomposed to create zinc and sulfur.

At wiring temperatures, sulfur reacts with iron to create iron sulfide, but no iron oxides are formed, which deteriorate the wear resistance of sintered iron-based friction materials.

Unlike known sintered iron-based friction materials which have barium sulfate as a sulfide-forming component, all the sulfur separated during sintering contributes to iron sulfide formation.

Zinc with its low melting point temperature, together with the lead which softens slightly on the friction surface and fills in the micro-roughness under a pressure of 25 kg/Crj, increases the strong contact area between the material and the object in contact.

In other words, the alignment is improved by increasing the area of strong contact.

Ingredients in the following proportions by weight: copper 3 tin 2 Zinc sulfide 3 Graphite 8 Nonoiro Serum 3 Lead 20 iron 61 sintered iron-based friction materials are recommended.

With the proportions of the above components, the zinc sulfide content is optimal, allowing all the sulfur to contribute to iron sulfide formation.

Sulfur inclusions are found in sintered iron-based friction materials when the zinc sulfide content increases even slightly, and the amount of these sulfur inclusions increases as the zinc sulfide content increases.

Sulfur inclusions tend to significantly reduce compressive and tensile strength, impact strength and hardness, thus reducing wear resistance.

A sintered iron-based friction material exhibiting the highest wear resistance and wear resistance is obtained with the provided proportions of ingredients.

These and other objects and novel features of the invention will be best understood upon consideration of the appended claims and the following detailed description of the preferred embodiments.

Powdered graphite and powdered zinc sulfide are dried at a temperature of 150°C.

Next, all the powders of copper, tin, zinc sulfide, graphite, pyroceramic, lead and iron are sieved, and as a mixture, the weight %
Weigh the following: Copper: 1,5-3 Tin: 1-2 Zinc sulfide: 2-4 Graphite: 6-10 Nonoiroceram: 2-5 Lead: 10-20 Iron: balance.

All ingredients are mixed in a mixer in the presence of a neutral liquid, such as oil.

The prepared mixture was heated to 4t/cr in a press mold. The molded article obtained, which is essentially a friction wrap, is sintered at a temperature of 1030° C. for 3 hours under a pressure of 20 kg/ffl and simultaneously fused to the steel matrix.

The obtained sintered iron-based friction material is subjected to wear resistance and friction tests on a friction test stand using the principle of applying a brake to a rotating inertial mass.

The obtained sintered iron-based friction material was braked 100 times, and then
It has 6 μm wear and 90% wear.

Compared with known materials, the wear resistance of the material under consideration is between 2 and
3 times higher, and 1.5 times higher for grinding.

The invention will be further illustrated by the following examples.

Example 1 Powdered graphite and powdered zinc sulfide were dried at a temperature of 150°C.

Next, all the powders were sieved through No. 0100 and No. 0160 sieves, weighed, and the following components were expressed in weight percent: Copper 15 Tin 1.0 Zinc sulfide 4.0 Graphite 6.0 Nonoiro Ceram 2.0 20.0 lead and 65.5 iron and then mixed for 6 hours in the presence of oil (0.5% of the weight of the mixture) in a mixer.

The prepared mixture is pressed into a press mold at 3t/cI? Pressed at a pressure of L, then sintered in a shaft furnace, at the same time 20kg/
The steel base was melted at a temperature of 1030° C. for 3 hours under a pressure of i.

Friction tests were conducted on the obtained sintered iron-based friction material on a test stand using the principle of applying a brake to a rotating inertial mass.

The following test data was obtained. Wear after 100 brakes
5μm Grinding 90% Example 2 The following proportions in weight percent: Copper 3 Tin 2 Zinc sulfide 3 Graphite 8 Nomiloceram 3 Lead 20 Iron 61 A friction material manufactured in the same manner as described in Example 1 from powder had the following properties. It had

Wear after 100 brakes: 4 μm Grinding: 90% Example 3 The following proportions by weight were prepared in the same manner as described in Example 1 from the following powders: Copper 3 Tin 2 Zinc sulfide 2 Graphite 10 Nonoiro Ceram 5 Lead 10 Iron 68 The friction material manufactured by the method had the following properties.

Wear after 100 brakes: 6 μm Grinding: 90% Example 4 The following proportions by weight were: Copper 1.5 Tin 1.0 Zinc sulfide ) 2.0 Graphite 6.0 Nomiloceram 2.0 Lead 1.0 Iron 775 A sintered iron-based friction material produced from powder in the same manner as described in Example 1 had the following properties.

Wear after 100 brakes: 5 μm Grinding: 90% Example 5 The following proportions in weight percent: Copper 3 Tin 2 Zinc sulfide 4 Graphite 10 Nonoiro Ceram 5 Lead 20 Iron 56 The same method as described in Example 1 was prepared from the powder. The sintered iron-based friction material produced in this way had the following properties.

Wear after 100 brakes: 5 μm Rubbing: 90% Certain narrow terminology has been used for clarity in describing the various embodiments of the disclosed invention.

However, the invention is in no way limited to such selected terminology, and each term is understood to include all equivalents that work in a similar manner and are used to solve similar problems. Should.

Although the present invention has been described in terms of preferred embodiments, modifications may be made to the sintered iron-based friction material without departing from the scope and spirit of the claimed invention, and such modifications will be readily apparent to those skilled in the art. I think it will be done.

All such substitutions and modifications are considered to remain within the scope and spirit of the invention.

Claims (1)

[Claims] Ingredients in the following proportions in 1% by weight: Copper 1.5-3.0 Tin 1.0-2.0 Zinc sulfide 2.0-4.0 Graphite 6.0-100 Nonoiro Ceram A wire-bonded iron-based friction material comprising 2.0 to 5.0 lead and 10.0 to 20.0 balance iron. 2% by weight of the following components: 3.0% by weight, 2.0% by weight, 3.0% by weight of zinc, 8.0% by weight, 3.0% by weight, 3.0% by weight of Nonoiroceram, 20.0% by weight, 61.0% by weight of iron. The sintered iron-based friction material according to item 1.