RU2003719C1 - Caked antifriction material on the basis of copper - Google Patents

Abstract

The invention relates to powder metallurgy, in particular to sintered antifriction materials based on copper. The inventive material has the following composition, wt.%: Aluminum 5-8; iron 2-4; the rest is copper. The material may additionally contain 6-8 wt.% nickel. The material has increased antifriction properties, low cost and is easy to manufacture 1 tab.

Description

The invention relates to powder metallurgy, and in particular, to sintered antifriction materials based on copper for the manufacture of antifriction parts operating under lubricating conditions at moderate to heavy loads.

Known sintered antifriction materials based on copper 1, containing aluminum 10-12 wt.%, Iron 6-8 wt.%, Copper and the rest, as well as methods for their manufacture 1, 2 - preparation of the mixture, pressing, sintering in containers with a fusible seal, in protective, reducing environments, backfill, etc.

The disadvantages of the known materials and methods for their MSI heating are their high cost and insufficiently high antifriction properties under moderate and heavy loads, under conditions of boundary lubrication. The reason for this is the rather complicated hardware design of sintering processes, the manufacture of structurally complicated containers with fusible closures, sealed muffles, the use of explosive, expensive gas media, the duration of heating and holding in a furnace during sintering, etc.

Closest to the claimed material and the method of its manufacture and antifriction properties is the material.

The purpose of the invention is to increase the antifriction properties and reduce the cost of manufacturing sintered anti-fiction materials based on copper by simplifying the method of their manufacture, which also requires a change in the quantitative relationships of the known compositions.

The problem is solved by heating, sintering and cooling the already known powder materials based on copper in air - without sealing muffles, containers, backfill and the use of reducing, protective gases, as well as reducing the amount of aluminum to 4-8%, iron to 2-4 and additional nickel administration of 6-10%.

The invention is as follows. The presence in the composition of the charge based on copper, as we have found, additives of tigan. zirconium, as well as aluminum and others, allows the sintering of compacts in air, since the copper base and the indicated alloying elements are very heat-resistant and the oxidation of the sintered contacts is so insignificant that the formed submicrofilms of oxides do not interfere with diffusion exchange processes at the contact. Secondly, Availability

additives - deoxidizers, for example aluminum, cleans the contacts of oxides due to exchange chemical reactions, deoxidizes copper oxides, forming dispersed inclusions of aluminum oxides, strengthening bronze, increasing wear resistance. In parallel with this, exothermic solid-phase reactions of the formation of copper - aluminum intermetallic compounds take place.

(CugAtfl) followed by structural phase transformations (according to the state diagram). Reactions begin at temperatures of heating the compact to 540-560 ° C in air and end within

5 minutes, when the bright background of the flared compact is compared with the background of the furnace chamber, after which the workpiece is removed, cooled in oil (combining impregnation and hardening - which improves tribological properties).

The excess heat is also sufficient for the consolidation (sintering) of the compact to occur, containing a certain amount of other alloying metals - iron,

5 nickel. The latter enhances the exothermic effect due to the reaction of the formation of triple intermetallic compounds AI Cu4Ni (established by x-ray analysis).

0 However, if aluminum and nickel are more than 8 wt.%, An excess of the liquid phase appears and the pressing loses its shape, size, strength, wear resistance, therefore, the compositions of the proposed material are refined, without which the proposed method loses its meaning. It is also unacceptable if the amount of iron in the charge exceeds 4 wt.%, The sample is disintegrated after sintering.

0

Example 1. Powders of copper, aluminum, iron (ratios of wt.%, See table 1) are mixed in a ball mill for 4 hours. Cylinders with a size of 10–6 t / cm are pressed from a finished batch with pressing forces of 5–6 t / cm . then placed in a preheated to 650-700 ° C electric furnace chamber (with automatic adjustment - shutdown in excess

0 exothermic heat) with an airy atmosphere. After 0.5-1 minutes of heating, ignition and sintering of the compact occurs. After 1-2 minutes, the consolidation processes end, the heated samples

5 are immersed in an oil bath for quenching and oil impregnation, which gives the material higher properties than the prototype. Sintered samples were tested for friction and wear at a speed of 1 m / s, loads of 3 and 6 MPa

Example 11 (comparative) - in the conditions of the prototype (see table 1).

As can be seen from the examples and tables, the main operational properties and the cost of manufacturing the proposed materials are more preferable than that of the prototype.

The claimed method and material due to its simplicity can be used on

any metal processing enterprise having forging and thermal sections.

(56) Fedorchenko I.M. and Pugina L.I. Composite sintered anti-friction materials. Kiev: Naukova Dumka, 1980, p. 338.

USSR copyright certificate No. 1640190, cl. C 22 C 9/01. 1988.

Performance characteristics of sintered anti-friction materials

Claims (2)

1. Sintered anti-friction material based on copper, containing aluminum and iron, characterized in that it contains components in: the following ratio, wt.%: Table continuation Aluminum 5-8 Iron2-4 Copper 2. The material according to claim 1, characterized in that that it additionally contains 6-8 wt.% Nickel.