DE1775322C2 - Multi-layer storage material, its input material and process for the production of the input material - Google Patents

Description

The invention relates to multi-layer bearing material with a support layer made of steel, one with this connected intermediate layer based on aluminum and a bearing layer composed of 55 to 95% by weight of aluminum, 5 up to 25% by weight tin, lead, cadmium, bismuth and / or Antimony and 0 to 20% by weight additives of silicon, copper, manganese, magnesium, nickel, iron, zinc, Chrome, zirconium and / or titanium. The invention also relates to a primary material for providing this multilayer storage material and a process for the production of the starting material.

With US Pat. No. 3,132,418, a method for producing a multilayer bearing material is disclosed indicated, according to which a bearing material with a support layer made of steel, an intermediate layer made of Aluminum and a sliding layer of tin-rich aluminum alloy is obtained; the tin rich Aluminum alloy can be made from 5 to 50 wt% tin, 0.1 wt% silicon, 0 to 4 wt% copper, 0 to 4% by weight nickel, 0 to 4% by weight manganese, 0 to 1% by weight iron, 0 to 5% by weight lead and / or 0 to 0.5% by weight beryllium, the remainder, namely at least 50% by weight, aluminum including the usual production-related! · Impurities exist. The known method is based on three endless belts the respective layer materials; these tapes are then cleaned on their surfaces heated and then compacted by a rolling treatment; after the compression can through Heating to 350 ° C can be remunerated.

As is well known, metallic aluminum is coated extremely quickly with an oxide layer, which the Connection of aluminum with other materials made more difficult. Since tin melts at 232 ° C, it migrates it easily touches the sand surface and when a ribbon made of tin-rich aluminum alloy is heated "Sweaty" from the aluminum alloy; the sweaty tin sticks to the compaction rollers and thus limits the degree of compression. For the reasons mentioned above, the known Process the adequate metallurgical connection of the individual layers considerable difficulties; in the The result can be fully satisfactory aluminum-based plain bearings that use the known method modern requirements for resilience, high-speed properties and resistance to "seizing" ' suffice not to be preserved.

British Patent 7 73 722 describes the production of corresponding multilayer bearings based on aluminum using a combined sintering and compaction process. A steel strip is chemically cleaned and galvanically coated with a nickel coating; a layer of powdery or particulate! applied to pure aluminum, which is then ^{sintered at 620 °} C. and metallurgically bonded to the nickel coating; then the aluminum layer is compacted. A mixture of aluminum powder and tin powder (for example 10 to 20% by weight tin) is applied to the compacted layer, the entire material is heated to about 90 ° C. and then compacted again.

In practice it has been found that among these Conditions no satisfactory cohesion between the particles of the bearing layer can be achieved could, with the result that when such bearings are heated under heavy loads, the Üinn from the sintered layer emerged and was removed, so that the bearing layer depleted of bearing material and for Tending to seize.

Furthermore, from US patent specification 30 94 415, a two-layer bearing with a carrier layer made of steel and a bearing layer made of aluminum / tin with up to 30% by weight of tin is known. Alloy of the intended composition can be applied. The carrier with the applied powder layer is then ^{heated to 370 to 590 °} C., the powder particles softening and melting together. It has been shown that tin also gets into the interface between the carrier and the bearing layer, as a result of which the adhesive strength of the bearing layer on the carrier is impaired.

Finally, from US Pat. No. 31 04 135 there is also a two-layer bearing with a carrier layer made of steel and a sintered-on powder layer made of, for example, a mixture of aluminum powder and tin powder or a master alloy made from these components is also known heated and compressed, but the temperature is always below the melting temperature of the lowest melting component is held. Here, a structure is obtained in which the low melting component forms solidified lakes surrounded by the aluminum structure. In practice it has been shown that even this camp is not completely satisfactory under high loads, since with corresponding Heating the tin could escape from the aluminum structure, so that under high loads there was still a risk of seizure.

The object of the present invention is to provide a plain bearing manufactured by powder metallurgy based on aluminum which improved one over the prior art proposals set out above Distribution of the bearing components in aluminum and low friction with high fatigue strength and seizure resistance.

Starting from a multi-layer bearing material with a steel carrier layer, one with this connected intermediate layer based on aluminum and a bearing layer composed of 55 to 95% by weight of aluminum, 5 up to 25% by weight of tin, lead, cadmium, bismuth and / or antimony and 0 to 20% by weight of silicon additives, Copper, manganese, magnesium, nickel, iron, zinc, chromium, zirconium and / or titanium is the one according to the invention This object is achieved in its most general form, characterized in that the intermediate layer consists of consists of powder particles sintered together, and the bearing layer consists of on the intermediate layer and sintered together, by spraying and quenching a molten mass from the Powder particles obtained named constituents, which are delimited from one another in the form There are aluminum-based particles which contain bearing metal in finely divided form, whereas there are no separate bearing metal particles between the particles.

According to a preferred embodiment of the invention Bearing material, the intermediate layer consists of an alloy with at least 55% by weight Aluminum and 0 to. 13 wt% silicon, 0 to

7% by weight copper, 0 to 14% by weight manganese, 0 to 6% by weight magnesium, 0 to 3% by weight nickel, 0 to 2% by weight iron, 0 to 8% by weight zinc, 0 to 1% by weight Chromium, 0 to 1% by weight zirconium and 0 to 1% by weight titanium.

The invention is further directed to a starting material for the above-mentioned storage material The primary material according to the invention is characterized in that there is a further layer on the bearing layer from powdered and sintered together of a mixture of bearing metal particles and particles Aluminum base is arranged

According to a preferred embodiment of the invention, the further layer consists of this primary material of 0 to 13% by weight silicon, 0 to 7% by weight copper, 0 to 1.5% by weight manganese, 0 to 6% by weight magnesium, 0 up to 3% by weight nickel, 0 to 2% by weight iron, 0 to

8% by weight zinc, 0 to 1% by weight chromium, 0 to 1% by weight zirconium, 0 to 1% by weight titanium, 0 to 50% by weight cadmium, 0 to 50 % By weight bismuth, 0 to 50% by weight antimony, 0 to 50% by weight lead, 0 to 50% by weight tin, the remainder aluminum.
The three-layer storage material is obtained from the four-layer starting material by removing the further layer. The purpose of the further layer is to improve the rolling and compacting of the particles of the special bearing layer provided according to the invention in accordance with the manufacturing process set out below, so that patent protection is sought for such an additional layer only in connection with the multilayer bearing material according to the invention. It is expressly stated that the general measure of providing an additional fourth layer on a three-layer storage material made up of, for example, other components and / or with a different structure, is not regarded as part of the present invention.
The invention also includes a method for producing the above-mentioned primary material. These? The method is characterized in that three different layers of powder particles, namely the intermediate layer, the bearing layer, to provide the aluminum or an aluminum alloy are melted together with the bearing metal, and the melt obtained is sprayed and quenched, and the further layer is pressed together at the same time , the compressed overall layer is then sintered and the sintered overall layer is then rolled onto a support layer made of steel.

According to a preferred embodiment of the method according to the invention, the entire layer is in sintered in two stages, namely in a first stage at about 200 ° C and in a second stage at temperatures between 310 and -, 90 ° C.

According to a further preferred embodiment of the method according to the invention, the entire layer can be tempered after rolling on the steel girder.

According to an important aspect of the invention, the material for the bearing layer is quenched with a jet of liquid or gas.
This special manufacturing process ensures a unique structure of the particles for the bearing layer. This structure has the following characteristics:
a) within a single bearing layer particle

the bearing metal component and the aluminum component are clearly distinguishable; i.e., the boundaries of the particles from these components are retained and can still be finished Product to be determined;

b) the bearing metal component is uniform through and through in each bearing layer particle distributed within the aluminum component; and

c) the bearing metal component is completely surrounded by the aluminum component.

Since in the context of this invention particles with this special structure by spraying and quenching a melt of aluminum components, Bearing metal component and optionally the other additives are obtained for such Particles hereinafter the term »premelted particles« is used. In the finished product shows a preferred embodiment of these premelted particles about 100 µm in length and one Thickness / width of about 40 μm, the average distance between the particles of bearing metal component within these premelted particles being approximately 5 μm.

Two sheets of illustrations also serve to explain an exemplary embodiment of the invention the F i g. 1 to 5; shows in detail

F i g. 1 shows a schematic representation of a continuously operating production plant for manufacture of storage strips and storage material according to the invention;

F i g. 2 shows a schematic representation of a bearing layer particle with aluminum and bearing metal components according to the invention;

F i g. 3 shows a schematic representation of the embedding of bearing material in aluminum particles in known ones To store;

4 shows a perspective illustration of a conventional and typical bearing construction; and

F i g. 5 shows a section through the starting material according to the invention

With F i g. 1, a crucible 10 for fusing aluminum-based particles 12 is shown. That Raw material 12 is added either in the form of bars or small pieces and can be a mixture of elemental components, a mixture of pure and alloyed material or a mixture of Represent alloys. The raw material 12 is to melt the individual components in placed in the crucible 10, heated and placed in it for a few minutes at a temperature of about 980 to 1040 ° C vigorously stirred until the melt has passed into a uniform liquid phase. A melting process this type is described in more detail with US Pat. No. 1,959,029. The crucible 10 is provided with an orifice 14, from which the molten mass is ejected under pressure in a continuous stream will. Room temperature water or air is directed onto the stream of molten mass, around the Stream to break up and spray and quench the molten mass, the resulting Particles are converted into the solid state. The water is by means of a nozzle 18 so against the molten mass directed that the resulting fine droplets or particles into a container 20 fall and be collected there. Suitable precautions, not shown, have been taken for the drainage of the water. It can also be used instead of Water or air, another gas is used to break up and quench the molten stream 16 will.

The premelted particles are then collected, dried and used for the storage layer of the Storage material according to the invention determined. For further processing, these particles 22 are in the central opening of a funnel-shaped collecting device 24 introduced. The collecting device 24

ίο has one on each side of the central opening further opening; the opening (shown on the left in the drawing) serves to receive powder particles 26 for the intermediate layer and the (in FIG The opening shown on the right is used for Ingestion of a mixture 28 of particles Bearing metal and particles of aluminum or aluminum alloy for the removable further layer 28 on raw material.

The powder particles 22, 26 and 28 are through the

Gap guided between the pressure rollers 30 and pressed together tightly. The resulting triple layer is sintered in two stages in the sintering furnace 32. The first holding time in the furnace 32 is about two hours about 200 ° C and is used to escape gas from the Mixture to prevent the formation of bubbles. This is followed by the second stage of sintering the triple layer at temperatures of 310 to 590 ° C im Sintering furnace. The exact temperature and time depend on the desired internal structure;

jo, for example, resulted in sintering at around 340 "C satisfactory results in the course of 30 minutes.

The sintered strip is then passed through rollers 34 and a steel backing surface rolled onto the surface of the base layer Depending on the final use of the storage material the material obtained is optionally subsequently in a tempering furnace 38 at a temperature of about 310 tempered to 400 ° C for about 30 minutes.

The from the powder particles 18, 22 and 26 and the

Strips composed of carrier layer are trimmed or punched out according to known Method for producing bearings to form a bearing of the usual shape as shown in FIG. 4 shown This results from the procedure described above The resulting primary material is in section with Fig. 5 Each aluminum-based layer is represented by the number representing the particles denotes from which each of these layers is built up

In order to expose the bearing layer 22, the Pre-material drilled to the appropriate dimensions by conventional methods until the layer 28 is completely is removed This operation can possibly be carried out before the bearing strip is punched out.

The structure of the bearing layer provided according to the invention is described below with reference to FIG 3 and 2 explained in more detail During the sintering and compression of a powdery mixture Aluminum particles and bearing metal particles becomes one Structure obtained, which is shown schematically with FIG. 3 is shown. The bearing metal LM is embedded here between the aluminum particles, even if the aluminum surfaces are completely combined to form a large aggregate. With the US patent 31 04 135 this structure is described in such a way that that the low-melting storage material forms individual separate lakes that of a matrix ans AiuminhimteDchen are surrounded. With this structure

known bearing layers, the bearing material is relatively easy to move within the aluminum matrix and can be removed if the bearing heats up as a result of overloading, which leads to the dreaded seizure of the bearing can occur.

In contrast, with F i g. 2 shows a particle 22 of the bearing layer provided according to the invention, which was obtained by spraying and quenching a molten mass of aluminum, bearing metal component and, if necessary, further additives. As shown, the bearing metal LM is in the form of individual particles distributed uniformly through and through within the mass of aluminum Al that forms the particle 22. When the particles 22 are compacted, essentially only the aluminum boundary layers of the particles 22 come into contact, which leads to an improved cohesion of the bearing layer. Thanks to the uniform distribution of the bearing metal component within the bearing layer particles 22, the mobility of the bearing material is: o reduced, with the result that the risk of loss of bearing material when the bearing is overloaded is also lower. As it passes through the rolls, each premelted particle 22 is stretched in the rolling direction; In this case, however, the bearing material, since it is finely and evenly distributed in each particle 22, is only slightly stretched. In a preferred embodiment, a typical fused powder particle 22 of the finished bearing layer is about 100 μm long and about 40 μm wide and thick; the average 3d distance between the particles of the bearing metal is approximately 5 μm.

The particles 26 for the intermediate layer, which ensure the connection between the support layer made of steel and the bearing layer, consist of a γ, material that does not contain any bearing material. This prevents storage material from being located at the boundary layer of the carrier layer, which would impair the strength of the connection. The particles 26 can be made of pure aluminum or of an alloy with at least 55% by weight of aluminum and 0 to 13% by weight of silicon, 0 to 7% by weight of copper, 0 to 1.5% by weight of manganese, 0 to 6% by weight magnesium, 0 to 3% by weight nickel, 0 to 2% by weight iron, 0 to 8% by weight zinc, 0 to 1% by weight chromium , 0 to 1% by weight of zirconium and 0 to 1% by weight of titanium. Particles 26 made of essentially pure aluminum are preferably used

The particles 22 for the bearing layer were melted by spraying and quenching a Mass obtained, and the resulting premelted particles consist of 55 to 95 wt .-% aluminum. 5 to 25% by weight tin, lead, cadmium, bismuth and / or Antimony and 0 to 20% by weight additives of silicon, copper, manganese, magnesium, nickel, iron, zinc, Chrome, zirconium and / or titanium.

The particles 28 for the further layer on the raw material, which are used to produce the three-layer Storage material is removed according to the invention, consist of a mixture of bearing metal particles and aluminum-based particles, including the above Accessories include. Preferably the ingredients this mixture is selected to the effect that a further layer is obtained which consists of 0 to 13% by weight Silicon, 0 to 7% by weight copper, 0 to 1.5% by weight Manganese, 0 to 6% by weight Magnesium, 0 to 3% by weight Nickel, 0 to 2% by weight iron, 0 to 8% by weight zinc, 0 to 1% by weight chromium, 0 to 1% by weight zirconium, 0 to 1% by weight titanium. 0 to 50% by weight cadmium, 0 to 50% by weight bismuth, 0 to 50% by weight antimony, 0 to 50% by weight lead, 0 to 50% by weight tin, the remainder being aluminum.

When rolling the triple layer from the pre-formed layers from the particles 26, 22 and 28 come the particles 26 and 28, respectively, in contact with the rollers. Preferably the composition of the particles 26 and 28 are selected to prevent sticking during rolling and the like or the same coefficient of friction is obtained with the rollers 30 to be substantially the same Powder supply between the rollers is achieved.

Table 1 below shows the compositions for the intermediate layer 26, the bearing layer 22 and the further layer 28 intended for removal are each given in% by weight.

Table 1 Between Base material 55 to 100 camp Further layer AI layer layer Bearing metal - Sn - 55 to 95 50 to 98 Pb - at least 5 CD - 0 to 25 0 to 50 Bi - 0 to 25 0 to 50 Sb 0 to 25 0 to 50 additions 0 to 13 0 to 25 0 to 50 Si 0 to 7 0 to 25 0 to 50 Cu 0 to 1.5 Mn 0 to 6 0 to 13 0 to 13 Mg 0 to 3 0 to 7 0 to 7 Ni 0 to 2 0 to 1.5 0 to 1.5 Fe 0 to 8 0 to 6 0 to 6 Zn Obis I Obis3 0 to 3 Cr Obis I Obis2 0 to 2 Zr Obis I Obis8 0 to 8 Ti Obis I Obis I Obis I Obis I Obis I Obisl

Table 2 below shows the compositions (in% by weight) for the intermediate layer 26, the bearing layer 22 and the further layer 28 intended for removal for three exemplary Embodiments of the starting material according to the invention specified.

Table 2

Intermediate layer

Camp-

Another layer

100% Al

94% Al
6% Si

0.8% Si
4.4% Cu
0.8% Mn
0.4% Mg
Remainder Al

8.5% Pb 20% Sn 1.5% Sn 1% Cu 4% Si Remainder Al 1% Cu Remainder Al 17% Pb 20% Pb 3% Sn Remainder Al 1% Cu Remainder Al 20% Sn 17% Pb 1% Cu 3% Sn Remainder Al Rest all inclusive

For this purpose 2 blue drawings 230223/9

Claims (8)

Patent claims: 1. Multi-layer bearing material with a steel carrier layer, one of which is connected to it Intermediate layer based on aluminum and a bearing layer of 55 to 95% by weight aluminum, 5 to 25% by weight tin, lead, cadmium, bismuth and / or Antimony and 0 to 20% by weight additives of silicon, copper, manganese, magnesium, nickel, iron, zinc, Chromium, zirconium and / or titanium, characterized in that the intermediate layer (26) of powder particles sintered together and the bearing layer (22) on the intermediate layer and sintered together by spraying and quenching a molten mass from the Powder particles obtained above mentioned constituents, v / which are delimited from one another in the form There are aluminum-based particles that contain finely divided bearing metal, whereas there are no separate bearing metal particles between the particles. 2. Storage material according to claim 1, characterized in that the intermediate layer (26) consists of a Alloy with at least 55% by weight aluminum and 0 to 13% by weight silicon, 0 to 7% by weight Copper, 0 to 1.5% by weight manganese, 0 to 6% by weight magnesium, 0 to 3% by weight nickel, 0 to 2% by weight Iron, 0 to 8% by weight zinc, 0 to 1% by weight chromium, 0 to 1% by weight zirconium and 0 to 1% by weight titanium consists 3. Starting material for the storage material according to claims 1 or 2, characterized in that on the bearing layer (22) a further layer (28) of powder sintered on and together Mixture of bearing metal particles and particles based on aluminum is arranged. 4. Starting material according to claim 3, characterized in that the further layer (28) from 0 to 13% by weight silicon, 0 to 7% by weight copper, 0 to 1.5% by weight manganese, 0 to 6% by weight magnesium, 0 up to 3% by weight nickel, 0 to 2% by weight iron, 0 to 8% by weight zinc, 0 to 1% by weight chromium, 0 to 1% by weight zirconium, 0 to 1% by weight titanium, 0 to 50% by weight cadmium, 0 to 50% by weight bismuth, 0 to 50% by weight antimony, 0 to 50% by weight lead, 0 to 50% by weight tin, the remainder being aluminum 5. A method for producing a starting material according to claim 3 or 4, characterized in that that three different layers of powder particles, namely the intermediate layer, the bearing layer, too the provision of which the aluminum or an aluminum alloy together with the bearing metal melted, and the melt is sprayed and quenched, and the further layer at the same time are pressed together, the compressed overall layer is then sintered and the entire sintered layer is then rolled onto a carrier layer made of steel. 6. The method according to claim 5, characterized in that the total layer is sintered in two stages, namely in a first stage at about 200 ° C and in a second stage at temperatures from 310 to 590 ^0C 7. The method according to claim 5 or 6, characterized in that the overall layer according to the Rolling is annealed on the steel beam. 8. The method according to claim 5, characterized in that the quenching of the material for the Bearing layer takes place with a liquid or gas jet