RU2434077C2 - ALLOY ON BASE OF QUAZI-CRYSTAL OF SYSTEM Al-Cu-Fe FOR APPLICATION OF WEAR RESISTANT NANO STRUCTURE COATING - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: here is claimed alloy on base of quazi-crystal system Al-Cu-Fe for application of wear resistant nano structured coating. Alloy contains copper in form of independent phase and tungsten carbide at the following ratio of components, wt %: copper 2-5, tungsten carbide 20-40, quazi-crystal of system Al-Cu-Fe - the rest. Also, quazi-crystal of system Al-Cu-Fe has the following composition, wt %: aluminium 65, copper 21.5-23.5, iron 11-13.5. Technical result of the invention is increased wear resistance due to increased micro-hardness of material together with increased adhesion and cohesion strength of applied coating.

EFFECT: alloy possesses high micro hardness and can be used for application of wear resistant coating.

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Description

The invention relates to precision metallurgy of wear-resistant alloys to obtain functional coatings operating in extreme operating conditions.

Known alloys with high wear resistance based on iron (RF patents No. 2359056; No. 2332509; No. 2337178), copper (RF patent No. 2349621) and aluminum (RF patent No. 2262554).

These alloys have a limited range of applications, especially in conditions of intense dynamic wear, elevated temperatures, and exposure to aggressive chemicals.

Therefore, intensive research and development has recently been carried out to create materials in nonequilibrium and super-nonequilibrium states (quasicrystals, amorphous materials).

Closest to the claimed and taken as a prototype is an alloy for obtaining wear-resistant conductive coatings based on copper with reinforcing nanoparticles of a quasicrystalline compound of the Al-Cu-Fe system [1].

The experimental work on obtaining a coating based on this alloy revealed the following two drawbacks: insufficient plasticity and a limited range of microhardness.

It should be noted that microhardness is the main indicator of wear resistance; it can be quickly determined for any material. The practice of operating wear-resistant alloys operating in extreme operating conditions shows that it is necessary to have a microhardness of the material not lower than 400-500 HV. The best quasicrystals provide a microhardness of not more than 190 HV.

The technical result of the invention is to obtain high wear resistance by increasing the microhardness of the material along with an increase in the adhesive and cohesive strength of the applied coatings.

The technical result is achieved due to the fact that the alloy based on a quasicrystal of the Al-Cu-Fe system additionally contains copper in the form of an independent phase and tungsten carbide. The homogeneous distribution of tungsten carbide in the quasicrystalline matrix provides an increase in microhardness up to 400-500 HV.

Optimal for the achieved effect is the alloy in the following ratio of components, wt.%:

copper 2-5 Wolfram carbide 20-40 Al-Cu-Fe quasicrystal rest

The known quasicrystal of the Al-Cu-Fe system with the following ratio of components, wt.%: Aluminum 65, copper 21.5-23.5, iron 11-13.5 is selected as the basis. These compositions ensure the stable existence of the quasicrystalline phase during coating deposition and during further operation [2].

Copper acts as a plasticizer when spraying coatings. It was experimentally established that the copper content in the alloy of less than 2% does not give the desired effect, and more than 5% leads to a decrease in hardness.

Tungsten carbide was chosen because it readily coherently binds to a quasicrystalline matrix. The content in the alloy of less than 20% tungsten carbide does not lead to a significant increase in hardness, and when the content is more than 40%, the alloy becomes brittle and unsuitable for application with a quasicrystalline matrix.

The practical implementation of the proposed technical solution was carried out according to the following scheme: smelting of the initial alloy by direct fusion of components; crushing of the obtained ingot; Coating by supersonic cold gas-dynamic spraying (HGDN)

The alloy was smelted in a high-frequency inductor of a L3-13 type plant with a power of 10 kW with an operating frequency of 880 kHz in alundum crucibles No. 3 and No. 4 with the following sequence of introducing charge components: Al-Cu-Fe quasicrystal → copper → tungsten carbide. The mass of the obtained ingots is 0.7-0.8 kg.

The obtained ingot was crushed sequentially on a Pulverisette 1 jaw crusher to a fraction of 3-5 mm, and then on a DEZI-15 type disintegrator to a fraction of 20-100 microns in accordance with the guidelines.

Functional coatings from the powder thus obtained were applied by the method of supersonic cold gas-dynamic spraying (HGDN) on a DIMET-3 type installation in accordance with the guidance documentation. The temperature of the heterophase flow during deposition did not exceed 130 ° C at particle speeds of 660-825 m / s, which ensures the preservation of the nanostructured state of the coating and the practical absence of porosity.

The substrates used were copper, nickel, and the Kh15Yu5 alloy. The thickness of the resulting coating is 18-20 microns, which provides the required consumer properties.

The microhardness of the coatings was studied according to the Vickers method using an AFFRI DM-8 automatic microhardness tester.

The results of the study are presented in table 1.

As follows from table 1, the proposed alloy has a higher microhardness compared to the known, which provides wear-resistant coatings.

Information sources

1. Patent of Russia No. 2362839, cl. С23С 24/04, В82В 3/00, 2009

2. Patent of Russia No. 2244761, cl. C22C 1/04, 21/12, 2005

Table 1 Comparison of the properties of the proposed alloy and prototype Alloy No. of swimming trunks Chemical composition, wt.% Microhardness, HV Notes copper Wolfram carbide Al-Cu-Fe quasicrystal Prototype 90 - 10 60 Low corrosion resistance fifty - fifty 200 40 60 180 Proposed one 2 twenty 78 400 High technological properties of the material 2 3,5 thirty 66.5 500 3 5 40 55 450 Alloy with composition outside the proposed values four 1.9 19 79.1 - It was not possible to obtain a continuous coating 5 5.1 40.1 54.8 370

Claims (1)

An alloy based on a quasicrystal of the Al-Cu-Fe system for applying a wear-resistant, nanostructured coating, characterized in that it contains copper in the form of an independent phase and tungsten carbide in the following ratio of components, wt.%:
copper 2-5 Wolfram carbide 20-40 Al-Cu-Fe quasicrystal rest,
moreover, the quasicrystal of the Al-Cu-Fe system has the following composition, wt.%: aluminum 65, copper 21.5-23.5, iron 11-13.5.