WO1989002365A1

WO1989002365A1 - Amorphous laminated material for sliding elements

Info

Publication number: WO1989002365A1
Application number: PCT/DE1988/000567
Authority: WO
Inventors: Erich Hodes
Original assignee: Glyco-Metall-Werke Daelen & Loos Gmbh
Priority date: 1987-09-15
Filing date: 1988-09-13
Publication date: 1989-03-23
Also published as: DE3730862A1; DE3730862C2

Abstract

A new laminated material has a functional layer (10), in particular sliding layer, of a material frozen in the amorphous state. This material frozen in the amorphous state can be a molecular alloy or a dispersion alloy. In the latter case, a metallic matrix (13) brought into and maintained in an amorphous state contains in the disperse state submicroscopically distributed globules of metallic material. This material finds particular application as sliding layer of sliding elements, since such slide bearing materials, both in molecular alloys and in dispersion alloys, present excellent sliding properties; their other essential properties are also considerably improved, when the material of the sliding layer (10) or at least the metallic matric of the sliding (13) is frozen in the amorphous state. The production of such sliding layers is effected by casting and quenching a foil strip at cooling rates between 10?6 K/s and 10?9 K/s.

Description

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Amorphous sliding element layer material £.

The invention relates to a layered material, in particular for the production of sliding elements, with at least one carrier layer and a functional layer made of metal alloy, in particular metallic dispersion alloy. The invention further relates to a method for producing such a layer material.

The known layered materials of this type have a more or less inhomogeneous structure in the functional layer, which in some cases of application of such a layer material, particularly in the case of sliding elements, has disadvantages. This inhomogeneity occurs in functional layers made of real metallic alloys due to crystallization or recrystallization phenomena. Such inhomogeneity occurs even more strongly and correspondingly disadvantageously in functional layers made of dispersion alloy. Since such dispersion alloys are generally formed from metallic constituents with very different weights, the heavier portions, for example lead in aluminum / lead dispersion alloys, have a strong tendency to segregate. Many paths have therefore already been taken in order to provide such dispersion alloys with the finest and most uniform possible distribution of the dispersed metal portion in the metallic matrix. However, the attempts undertaken to this end have largely failed, so that the functional layers of dispersion alloy known to date are still far from a uniformly fine distribution of the dispersed metal constituents and even more so than a homogeneous structure. In the case of dispersion alloys, the components of which have a miscibility gap, these difficulties become even greater because at this miscibility temperature of the melt mixture, the melt already breaks down into separate phases of the different mixture components and - due to the large difference in density or weight of the individual components - very rapid segregation and coagulation occur in the molten alloy.

For the production of functional layers from such dispersion alloys, for example, DE-OS 31 37 752 has disclosed the formation of metal powders by atomizing a melt mixture and sintering this metal powder together on the carrier layer. However, this method leads to a highly inhomogeneous structure of the functional layer.

From DE-AS 21 30 421 a method for producing a composite metal strip is already known, in which molten aluminum passes through an opening in the bottom of the crucible and molten lead in a thin, thread-like flow through the molten aluminum also into the Bottom opening of the crucible is guided. The melt mixture of aluminum and lead formed in the bottom opening of the melting crucible is then swirled and mixed by means of gas jets and blown onto the upper surface of the substrate carried past. A functional layer formed in this way is still in to a great extent inhomogeneous, the lead particles, owing to their much greater density, tending to segregate and coagulate to a great extent when the swirling stream of melt mixture hits the surface of the substrate.

In a method known from DE-AS 22 63 268, a melt mixture of lead and aluminum is thrown off to the side by means of a rotor designed in the form of a suction lifter in the form of fine particles and thrown off on a baffle wall and quenched on a baffle wall and solidified into scale-like material. However, this scale-like material cannot be combined into a closed layer without the application of heat and pressure, and again

Demixing occurs to a large extent and leads to strong inhomogeneity of a functional layer formed in this way.

The task of the invention, however, is one

Producing layered material of the type mentioned at the beginning in a simple, safe and easy-to-carry out process and thereby improving the fine distribution of the dispersed metal component up to close to a homogeneous structure of the functional layer.

This object is achieved according to the invention in that the metal alloy of the functional layer is in an amorphous state, in the case of dispersion alloys at least its matrix component is amorphous and the dispersed metal component is globally and sub-microscopically finely distributed in the amorphous metallic matrix. _. -

As a result of the invention, the functional layer is provided with significantly improved properties due to the amorphous state of its material. For example, the strength of the functional layer is significantly increased. The shear modulus is considerably lower than with corresponding crystalline alloys. The elasticity of the functional layer is significantly increased. Similarly, despite the extremely high strength, the ductility and toughness of the functional layer were improved. All of these improved properties come into their own when the functional layer is used as a sliding layer. In such a case, sliding layers made of aluminum / lead dispersion alloys, for example those with a lead content between 8% and 40% by mass, or sliding layers made of lead bronze, come into consideration among many possibilities. In any case, the lead portion is then globally distributed in the respective aluminum matrix or copper matrix.

For the production of the layer material according to the invention, a method is considered in which an alloy melt or the melt mixture of a dispersion alloy with the desired alloy composition is poured out under high pressure to form a film strip and with a cooling rate between approximately 10 6 and approximately 109 K / s is quenched to achieve the amorphous state - at least the matrix component in the case of a dispersion alloy - and in which the film strip thus formed is plated onto the carrier layer while maintaining the amorphous state of its metallic material. This method can be carried out, for example by spraying a fine jet of the alloy melt or the melt mixture onto a rotating, forcibly cooled cylinder for the continuous formation of a film strip, the outer surface of this cylinder not being bonded to the

Alloy melt or a component of the melt mixture should enter. With this procedure, however, only the side of the film strip lying on the cylinder surface is cooled. However, if desired, the exposed surface of the film strip can also be cooled, for example by means of cold gas jets or cooled rollers. Another method of production in the context of the method according to the invention provides that the foil strip is formed by injecting one or more parallel fine jets of the alloy melt or of the melt mixture into a roll gap, the rolls being cooled and no binding to the alloy melt or to their outer surfaces Should form part of the melt mixture.

It has been found that foil tapes of several centimeters wide and about 0.5 mm thick can be produced safely and continuously in this way, preferably in a finished thickness of the intended functional layer. The process according to the invention can be significantly improved if one or more crystallization inhibitors (glass formers) are added to the alloy melt or the melt mixture in a total amount between about 0.2 to 2.0% by weight. In the case of the formation of a functional layer with aluminum or copper as the main constituent, silicon, boron, phosphorus, iron, cobalt, titanium, for example, may be used individually or as a mixture as crystallization inhibitors (glass formers). The connection of the film strip formed during the process according to the invention to the carrier layer must in any case be carried out while maintaining the amorphous state in the material of the film strip. For this purpose, plating the film strip onto the carrier layer with the aid of ultrasound welding or explosion welding can be considered. If the film strip to be connected to the carrier layer in this way consists essentially of aluminum, an intermediate film of pure aluminum can be incorporated between the film band and the carrier layer in order to improve the bond strength. ^" The same can be taken into account when attaching foil tape with the main component copper using an intermediate foil made of pure copper. The foil tape can also be attached to the backing layer by soft soldering. Good bonding of the foil band to the backing layer can also be achieved Achieve gluing, although in order to ensure heat conduction between the functional layer and the carrier layer, heat-conductive, in particular metallic filler, for example fine silver powder or copper powder, should be mixed into the adhesive In such a case, however, it will not be possible to avoid a certain crystallization process during the roll cladding in the film strip if, on the one hand, high bond strength between the functional layer and the carrier layer and, on the other hand, secure retention of the If amorphous conditions are desired in the material of the functional layer, roll cladding will generally be less recommended. Embodiments of the invention are explained in more detail below with reference to the drawing. Show it:

1 shows a greatly enlarged partial section of a layer material according to the invention in one embodiment;

2 shows a greatly enlarged partial section through a layer material according to the invention of a second embodiment;

Fig. 3 is a diagram for a method of manufacturing a film strip from amorphous metallic material and

Fig. 4 is a diagram for a modified manufacturing method for a film strip made of amorphous metallic material

The example in FIG. 1 is a

Layer material 10 with carrier layer 11 made of steel and functional layer 13 as a sliding layer made of aluminum / lead dispersion alloy with a lead content of 8% by mass, 1% by mass of silicon as crystallization inhibitor, the rest being aluminum. As can be seen from FIG. 1, lead particles 14 dispersed in the globular, submicroscopic distribution are located in the amorphous aluminum matrix of the functional layer 13. The silicon is dissolved as a "glass former" in the amorphous aluminum matrix. In the example in FIG. 1, the functional layer 13 is attached to the carrier layer 11 by ultrasound welding. Between the functional layer 13 and the carrier layer 11, a binding agent layer 12 made of pure aluminum is provided in this example.

In the example in FIG. 2, there is a layer material 10, the carrier layer 11 of which is made of steel and which carries a functional layer 13 of lead bronze. In this example, the functional layer 13 contains an amorphous copper matrix and in this globular, submicroscopically finely distributed lead particles 15, of which only the larger lead particles appear in the illustration in FIG. 2, while the large amount of lead particles in the figure 2 selected magnification do not appear. Above all, FIG. 2 shows that in the amorphous copper matrix, the crystallization of the copper that was typical for lead bronze was avoided.

In the example in FIG. 2, the functional layer 13 is glued onto the carrier layer 11. The erkenn¬ in Figure 2 face the adhesive layer 16 in this example includes wärme¬ conductive copper particles 17, which have been mixed in the form of a fei ^g en copper powder to the adhesive.

For the production of the layer material 10, a film strip 20 is first formed from the metallic material selected for the respective functional layer 13. This metallic material can vary depending on

Purpose of the functional layer to be a more or less pure metal. In general, however, a real metallic alloy or a metallic dispersion alloy becomes the material for the functional layer - q _

choose. Functional layers 13, which are intended to serve as sliding layers on sliding elements, can be considered, for example, on real metallic alloys, lead / tin alloys, lead / tin / copper alloys, lead / tin / antimony alloys, etc. ^'Further, in consideration dispersion alloys based on aluminum / lead, aluminum / tin, aluminum / bismuth, aluminum / antimony, copper / lead, copper / iron, lead / iron and others. A crystallization inhibitor or "glass former" in a total amount of between about 0.2 to 2.0% by weight can preferably be added to the respective real metallic alloy or metallic dispersion alloy. Depending on the type of metallic alloy or metallic dispersion alloy, silicon, boron, phosphorus, iron, cobalt, titanium and others can be considered. The alloy or the dispersion alloy is melted and placed in a crucible 21 which has an outlet 22 at its lower end for a fine jet 23 of the melt. As indicated by arrow 24, the crucible 21 is supplied with a pressurized gas from the top, which is inert to the melt and also dissolves as little as possible in the melt. The crucible 21 is surrounded in the illustrative examples by an induction coil 25 with which the melt is kept at a predetermined temperature at which it is sufficiently liquid to be pressed through the outlet 22 and form a fine jet 23. If a dispersion alloy is to be processed, the

Crucibles 21 additionally have stirring devices or vibrating devices which continuously mix the melt mixture of the dispersion alloy intensively and in a fine distribution of its mixture components. hold. These mixing devices or vibrating devices are not shown in FIGS. 3 and 4 for the sake of simplicity.

In the example of FIG. 3, the thin jet 23 of molten alloy or melt mixture of a dispersion alloy pressed out of the crucible strikes the surface of a strongly forced-cooled cylinder 26. The angle v is chosen so that the jet 23 immediately distributed in the manner of a narrow band without lateral spraying or splashing back on the surface of the cylinder 26. This band becomes thin like a film and very quickly cools to the film band 20 on the surface of the cooled cylinder 26. The cooling takes place primarily from the cylinder 26. However, in order to also intensively cool the exposed side of the film strip 20, the example in FIG. 3 provides that 27 jets 28 of cold gas or cold liquid are directed onto the film strip 20 by means of a nozzle arrangement. After the film strip 20 has been taken along by the cylinder 26 for a predetermined distance, it is lifted off the cylinder 26 by means of a knife-type strip remover 29. The cooling speed of the film strip 20 on the cooled roller 26 with the cooperation of the cooling jets 28 is above 10 g K / s up to about 10 K / s. Accordingly, it is a real one

Alloy that forms the foil strip 20 in amorphous

Condition kept. If a dispersion alloy is processed with a miscibility of its components, a film strip 20 results, in which the

Matrix-forming component of the dispersion alloy is in the amorphous state, while in This matrix dispersed component is globular, submicroscopically finely distributed in the matrix

In the mode of operation according to FIG. 4, the melt of a metallic alloy provided for the functional layer 13 (FIGS. 1 and 2) or the melt mixture of a dispersion alloy is placed in a crucible 21 and pressurized there in accordance with arrow 24 by means of a gaseous medium. The crucible 21 allows the melt or the melt mixture to enter the roll gap 30 between two rolls 31 and 32 in a jet at its lower end 22. Both rollers 31 and 32 are strongly cooled. The width of the nip 30 is set in accordance with the desired thickness of the film strip 20 to be produced. As indicated in FIG. 4, a small accumulation of melt or melt mixture is formed in front of the roller gap 30, without any significant delay in the transfer of the melt or the melt mixture from the outlet 22 of the crucible 21 into the roller gap 30 . The two rollers 31 and 32 thus do not exert any noteworthy pressure effect on the film strip to be formed, but only a certain smoothing effect on the surface of the film strip 20 being formed. Furthermore, the small material accumulation at the roller gap 30 results in a distribution of the melt or Melt mixture made in the axial direction of the rollers 31 and 32, so that film strips of greater width than in the case of Figure 3 can be produced. To this axial

To facilitate distribution of the melt or the melt mixture along the nip 30, the crucible 21 is arranged in an inclined position with the angle θ in order to in this way to inject the melt or the melt mixture pressurized in the crucible 21 directly into the roller gap 30.

The surfaces of the rollers 31 and 32 are designed in such a way that they form virtually no bond with the molten alloy or an alloy component or one of the components of a dispersion alloy to be processed. In order to keep the film strip formed in the nip 30 on the surface of the roller 31, the upper roller 32 is associated with a tape remover 33. In order to cool the film strip remaining at the outlet of the roller nip 30 on the surface of the roller 31 on the now exposed surface, a cooling nozzle 34 is initially provided which directs a jet of cold gaseous or liquid medium against the outlet of the roller nip 30 . The side of the film strip 20 remaining on the surface of the roller 31 is further cooled by the cooling roller 31.

The cooling roller 31 is compared with a third cooling roller 35, which is strongly forced-cooled and to further cool the film strip 20 on the side quenched by the roller 32 and the coolant jet from the nozzle 34. Behind the third cooling roller 35 there is also a fourth cooling roller 36 which takes over the film strip from the roller 31. To this end, the roller 31 is assigned a belt pickup 37. For an effective edition de? Foil tape 20 on the surface of the fourth

To force the cooling roller 36, a likewise cooled pressure roller 38 is juxtaposed with the fourth cooling roller 36. The fourth cooling roller 36 then Foil tape 20 removed by means of a tape remover 39. Further cooling rolls are indicated at 34 'and 34 ".

Compared to the procedure according to Figure 3 is in the

Example according to Figure 4, a further intensification of the cooling process is carried out, so that on the film strip

Cooling rates ranging in size from 10 8 K / s to 109 K / s can be achieved. This results in the possibility of also film strips of greater thickness, for example

Produce 0.5 mm thickness and stake out over its entire thickness so intensely that the amorphous state of the metallic material is frozen during the cooling process. Finally, the method of operation according to FIG. 4 also offers the possibility of producing wider film strips, in particular if a plurality of crucibles 21 are arranged next to one another along the roller gap 30.

Ό S film tape produced according to one of the working methods according to FIG. 3 or FIG. 4 is then laminated onto a carrier layer, either by ultrasonic welding or explosion welding, with a corresponding pure metal foil 12 between the respective carrier layer 11 and the function layer 1 (FIG. 1 ) is to be inserted, for example a foil made of pure aluminum or a foil made of pure copper. It is also possible, in particular in the case of functional layers 13 based on copper, to solder the film web produced in the manner described above by soft soldering on the carrier, for example a steel strip previously copper-coated on the side receiving the functional layer fasten. Adhesive bonds, as explained above in connection with FIG. 2, can also be considered. If it is contemplated to apply a film strip 20 forming the functional layer 13 (FIGS. 1 and 2) to a carrier by roll cladding, such a connection method should be carried out with great care, so that recrystallization does not occur due to the effect of increased temperature and increased pressure Foil tape 20 or the functional layer 13 occurs.

B e z u g s z e i c h e n l i s t e

10 layer material

11 carrier layer

12 bonding agent layer

13 functional layer

14 lead particles

15 lead particles

16 adhesive layer

17 copper particles

20 foil tape

21 crucibles

22 outlet

23 jet (molten alloy / melt mixture)

24 arrow

25 induction coil

26 cylinders

27 nozzle arrangement

28 jets (cold gas / cold liquid)

30 nip

31 roller

32 roller

33 tape takers

34 cooling nozzle

35 chill roll

36 chill roll

37 tape takers

38 forcing roller

39 tape takers

Claims

O 89/02365

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P a t e n t a n s r u c h e

1) Layer material, in particular for the production of sliding elements with at least one carrier layer and a functional layer made of metal alloy, in particular metallic dispersion alloy, characterized in that the metal alloy of the functional layer (13) is in an amorphous state - at least in the case of dispersion alloy whose metallic matrix component is amorphous - and the dispersed metal portion is globular, submicroscopically finely distributed in the amorphous metallic matrix.

2) Layer material according to claim 1, characterized gekenn¬ characterized in that the functional layer (13) is formed as a sliding layer of aluminum / lead dispersion alloy - whose lead content between 8% and 40%

Mass fraction is and globally distributed in the amorphous aluminum matrix. 3) Layer material according to claim 1, characterized gekenn¬ characterized in that the functional layer (13) is formed as a sliding layer of lead bronze, the lead portion is globularly distributed in the amorphous copper matrix.

4) Layer material according to one of claims 1 to 3, characterized in that the metal alloy of the functional layer (13) or its matrix one or more of the alloy components silicon, boron, phosphorus, iron, cobalt, titanium in a total amount between 0, Contains 2 and 2.0 wt .-% as crystallization inhibitor (glass former).

5) layer material according to claim 1, characterized in that the functional layer (13) by ultrasonic welding or explosion welding is attached to the carrier layer (11).

6) Layer material according to claim 5, characterized in that the functional layer (13) contains aluminum as an essential metallic component and between the functional layer (13) and the carrier layer (11) a bonding agent layer (12) made of pure aluminum is provided is.

7) Layer material according to claim 1, characterized gekenn¬ characterized in that the functional layer (13) is glued to the carrier layer (11) and the adhesive layer (14) thermally conductive filler (17), for example fine silver powder or fine copper powder , contains. 8) layer material according to claim 1, characterized gekenn¬ characterized in that the functional layer (13) on the carrier layer (11) is soft soldered.

5 9) Method for producing layered material according to one of claims 1 to 8, characterized in that an alloy melt or the melt mixture of a dispersion alloy with the desired alloy composition under increased pressure to one

The TD film strip is poured out and quenched at a cooling rate between about 10 6 and about 109 K / s while maintaining the amorphous state - at least the matrix component in the case of a dispersion alloy - and that the 15 film strip thus formed is kept while maintaining the amorphous state Material is plated on the carrier layer.

10) Method according to claim 9, characterized in that the functional layer made of a dispersion alloy with a gap in the mixture, for example a dispersion alloy based on Al-Pb, Al-Sn, Al-Bi, Al-Sb, Cu-Pb, Cu-Fe, Pb-Fe, formed and the melt mixture of this dispersion alloy for pouring

25 heated to a temperature above the mixing gap of the constituents of the dispersion alloy under increased pressure or kept in fine distribution of their mixture constituents by continuous intensive mixing.

30

11) Method according to claim 9 or 10, characterized gekenn¬ characterized in that the alloy or the melt mixture of a dispersion alloy one or more crystallization inhibitors (glass formers) in a total amount

3 between about 0.2 to 2.0 wt .-% is mixed. 12) Method according to claim 11, characterized in that one or more of the substances silicon, boron, phosphorus, iron cobalt, titanium is used as a crystallization inhibitor (glass former).

5

13) Method according to claim 9, characterized in that the film strip by spraying a fine jet of the alloy melt or the melt mixture onto a rotating, force-cooled cylinder

, 10 which is formed continuously, the jacket wall of which consists of a material with a high thermal conductivity that does not bind with the alloy melt or the melt mixture and one of its components.

15 14) Method according to claim 13, characterized in that the film strip is also 'cooled on its free surface' during its formation on the cooled cylinder, for example by means of cold gas jets or cooled rollers.

20th

15) Method according to claim 9, or 10, characterized gekenn¬ characterized in that the film strip by injecting one or more parallel fine jets of the alloy melt or the melt mixture into one

25 nip is formed, the rolls being cooled, not equipped with the alloy melt or the melt mixture and one of its constituent surfaces and having a jacket wall made of material with high thermal conductivity. 16) Method according to one of claims 9 to 15, characterized in that the film strip is already produced during its manufacture in the finished thickness of the functional layer, for example of 0.5 mm.

17) Method according to one of claims 9 to 16, characterized in that the foil strip is plated onto the carrier layer with the aid of ultrasonic welding.

18) Method according to one of claims 9 to 16, characterized in that the film strip is fastened on the carrier layer by means of explosion welding.

19) Method according to claim 17 or 18, characterized gekenn¬ characterized in that a foil strip made of alloy with aluminum as the main component, for example aluminum / lead dispersion alloy or aluminum / tin dispersion alloy used for the formation of the functional layer is and a pure aluminum intermediate film is integrated between the carrier layer and the film strip forming the functional layer.

20) Method according to one of claims 9 to 16, characterized in that the foil strip is fastened to the carrier layer by soft soldering.

21) Method according to one of claims 9 to 16, characterized in that the film strip is glued to the carrier layer, the heat-conductive adhesive, in particular metallic filler, for example fine silver powder or fine copper powder, being admixed.