SU975683A1 - Antifriction wear resistant material - Google Patents

Description

The invention relates to the production of structural wear- and heat-resistant materials with the aim of using them in the national economy as a support, thrust bearings, mechanical seals in centrifugal pumps transporting liquid and bulk media, such as oil distillation products, cement clinker, etc. .

The refractory material is also intended to be used in the dry friction mode, i.e. without lubrication under high loads and sliding speeds.

A known material, inclusive, wt.%: Silicon carbide 20-65, carbon 75-10, silicon 5-23 and up to 6% of iron and aluminum impurities, which is obtained by impregnating graphite with a melt of silicon with the inclusion of iron and aluminum, in vacuum at 17002050С 1.

However, this material is practically inoperative in friction units, even providing short-term work without lubrication.

The closest to the proposed technical essence and the achieved result is a composite material composition, wt.%:

20-38

Carbon

19-50 Silicon Carbide

1.0-2.0 Silicon

10-60 Copper

obtained by impregnation in a vacuum or inert medium of a carbon base with a melt of silicon with copper in the amount of 20-80 wt.% at 1250-1650 C 2.

ten

The disadvantages of the known composite material are relatively low wear and heat resistance under constant loads and with slip masses without lubrication,

15 which, of course, to a certain extent limits the use of the final material in these conditions.

In addition, it was found that the presence of wear and tear products

20 copper in the transported liquid, leads to a sharp deterioration in its quality.

Thus, the known material does not satisfy the main requirement,

25 I imposed on antifriction material - increased wear resistance under dry friction conditions with increasing speed and load.

The purpose of the invention is to increase the material's wear resistance. The goal is to achieve that antifriction wear-resistant material, including silicon carbide carbon, silicon and a metal component, contains nickel as a metal component in the following ratio of components, weight,%: Silicon carbide Carbon Silicon 0.5-3.8 Nickel 8.2- 60.5 Material. Possesses self-lubricating properties when operating without lubrication under conditions of high temperatures due to the introduction of nickel into its composition, which can be used in all temperature modes of friction, and especially at high temperatures to form on the working surface. ne-carbon This anti-wear layer slab composition has a carbon-nickel another important feature - not form in the process of friction even at high loads, wear debris that ultimately, as indicated, the driveshaft in reduced quality protractor detectable product. The strength of the working surface is additionally ensured by a silicon carbide carbide that takes on various types of axial and corrosion loads. The content of free carbon in the material in the amount of 15-35 wt.% Provides the best tribometric characteristics of the material and the deviation towards its decrease from the proposed one degrades the effect of lubrication. The carbon content is above 35 vol. leads to a decrease in mechanical strength and partial delamination of the final material. The silicon carbide cage provides heat resistance and strength to the final material; therefore, a decrease in silicon carbide in the mass of less than 24 wt.% Entails a decrease in these characteristics, while an increase in excess of 53 wt.% Significantly increases its mechanical strength while increasing brittleness. Unreacted silicon in the refractory mass does not have any noticeable effect on the properties of the final material. The introduction of nickel practically eliminates its harmful effect - the formation of microcracks on the finished products upon cooling after their heat treatment. The introduction of nickel to the material to the minimum limits provides it with the required antifriction properties at a higher local temperature on the friction surface as compared to copper. The content of nickel is more than 60.5% of the weight, although it increases the heat resistance and strength of the final material, but at the same time impairs its friction characteristics - there is a phenomenon of contact seizure, which leads to a partial tearing of the material and intensive wear. The deterioration of the friction process in this case is also affected by the decrease in the proportion of free carbon. Thus, the use of antifriction material of the proposed composition as friction elements allows increasing its wear resistance, heat resistance, and mechanical strength. Antifriction material is manufactured according to the following technology: a ring part made of carbon material Fz 80-120 mm, p 40-80 mm, And 40-40 mm, is loaded into an electric vacuum furnace, vacuum of mm Hg is created, heated to 1200- 1850 ° C at a speed of 3050 C / min and kept in a given alloy for 30-40 minutes, followed by cooling with the furnace to 80O-10.00 ° C. Cooling to room temperature is carried out in air. According to the described technology, three compositions of the material are prepared (Table 1). Compositions that go beyond those proposed have low strength, wear resistance and heat resistance. Table 1

In tab. 2 shows the properties of the proposed material and known, tested in the same conditions.

Comparative antifriction tests were carried out on the frictionless installation of a lubricant, using a counterclaim of the same name, treated with a surface finish of 0.32 with a slip speed of 2.0 m / s, with a load of 15 kgf / cm and 4000s.

T. lbl and c and 2

Proposed

1 2 3

1.5

25

35

As can be seen from the table. 2, the proposed material is 15–20% higher than the mechanical strength of the well-known, almost 2 times better in durability with a greater load (15 kgf / cm) and a temperature of 400 s.

The noted advantages of the proposed material make it possible to increase the warranty service life of the pumping equipment by 2 times.

Claims (2)

1. The UK patent number 1394106, cl. With 1 A, pub. 1972. 2. USSR author's certificate According to the application 2842997, cl. From 04 To 35/52, 1980.