Method for producing a sliding layer of a sliding bearing using a material

Abstract

The present invention relates to a method for manufacturing a sliding layer of a sliding bearing, using the following alloys and / or materials, namely one of SnSb8Cu4, SnSb12Cu6Zn, CuSn12Ni2, CuAHOFe1, tin aluminum bronze, aluminum materials and alloys made thereof, for producing a sliding layer of a sliding bearing by a method based on laser coating of one of these alloys and / or materials to a substrate, wherein the alloy and / or material for coating application is in the form of powder or compacted powder or in the form of wire.

Description

[0001] The invention relates to the use of alloys and / or materials for producing a sliding layer of a sliding bearing and to a method for producing a sliding layer of a sliding bearing using alloys and / or materials, in particular tin-based alloys and bronze-aluminium alloys.

[0002] To produce a high-load-bearing metallic coating in combination with a metallic carrier material, a special high-load-bearing metallic substance is used, which is applied to the metallic carrier material (substrate). High-load-bearing materials with good sliding, running-in, embedding and emergency running properties are often used on a tin basis. In addition, additional elements must be used if the coating is subjected to greater thermal loads or if the static and dynamic loads on the coating are high, for example in the case of bearings subject to impact and shock stresses. Typical application examples are high-load-bearings in compressors, pistons and expanders as well as rolling mills.

[0003] In the case of hydrodynamic plain bearings with a sliding layer made of a tin-based alloy ("white metal"), this alloy is usually applied by a centrifugal method or a gravity casting method. The substrate is previously tinned in order to achieve a good bond with the subsequently applied alloy layer.

[0004] In order to achieve a good bond between the metal layers, the bonding surfaces of the metal supports had to be pretreated up to now due to adhesion problems. For bonding casting between metal substrates such as steel, cast steel, grey cast iron, bronze and tin-containing coating materials, for example, pickling agents and / or tinning of the bonding surfaces are required. This results in complex, cost-intensive and often also environmentally harmful process steps. For certain process and material combinations, additional metallic intermediate layers are required, which in turn entails considerable costs.

[0005] Such coatings are currently manufactured with the aid of complex casting methods. These require precise temperature control and often require the use of pickling agents, such as zinc chloride compounds, which are toxic in most cases, to pre-treat the substrate material. In addition, an alloy that is castable and can be applied to a carrier material without melting or other segregation phenomena is required. In addition, in the casting method, a prescribed heating of the substrate and a prescribed cooling after casting are necessary in order to achieve good crystal structure quality, high uniformity and bonding by uniform temperature control in the two layers. After the tin-containing metal layer is applied, a post-processing of cutting is also required to give the coating its final shape. This requires the provision of casting equipment and corresponding monitoring and post-processing devices. In practice, it is usually difficult to cast a uniformly crystallized metal layer that can withstand high loads for complex substrates with large variations in material thickness.

[0006] The "IWK" alloy group is a special tin-based alloy for plain bearings that contains 11-14% antimony, 5-7% copper, 0.1-3% bismuth, 0.1-2% zinc and 0.01-0.5% tellurium. This group can only be processed to a very limited extent by conventional centrifugal methods or gravity casting methods, because the tinning of the base body is not sufficient to achieve a good bond. A special and complex tin-zinc pretreatment is required. As a result, the "IWK" alloys have not been able to gain a foothold in the market to date, despite their outstanding properties.

[0007] The object of the present invention is therefore to provide: the use of alloys and / or materials for producing sliding layers of sliding bearings and methods for producing sliding layers of sliding bearings using alloys and / or materials, in particular tin-based, bronze and aluminum alloys, which can simplify the production process and improve the properties of the sliding bearings.

[0008] This object is achieved by the combination of features according to the invention.

[0009] According to the invention, the use of one of the following alloys and / or materials, namely SnSb8Cu4, SnSb12Cu6Zn, CuSn12Ni2, CuAl10Fe1, tin and aluminum bronze, aluminum materials and alloys thereof, for producing a sliding layer of a sliding bearing is proposed by subjecting one of these alloys and / or materials to a laser-based coating method on a substrate. The alloy and / or material for coating application is in the form of a powder or compacted powder or in the form of a wire.

[0010] When using the alloys SnSb8Cu4 and SnSb12Cu6Zn, process reliability is increased, economic efficiency is increased, and bond strength is increased. Processing tin and aluminum bronze, such as CuSn12Ni2 powder and CuAl10Fe1 powder, in laser-based coating methods allows new sliding layer compositions to be achieved. These materials have good friction properties under critical operating conditions. Increased load capacity, "downsizing" and improved mechanical properties as well as simultaneously increased temperature conditions are just some of the possibilities that can be effectively utilized.

[0011] In an advantageous embodiment variant, it is provided that the alloy is a tin-based alloy with proportions of 11-14% antimony, 5-7% copper, 0.1-3% bismuth, 0.1-2% zinc and 0.01-0.5% tellurium.

[0012] The "IWK" alloy used can be used without complicated pretreatment. The technical properties of the "IWK" alloy, such as strength, toughness, creep resistance and temperature resistance, exceed those of previously established white metal alloys. Therefore, use under critical operating conditions is particularly conceivable. Due to the higher load capacity, the possibilities achieved through "downsizing" can also be utilized.

[0013] In one embodiment of the present invention, it is provided that the particle size of the powder is 1 μm-250 μm. In this way, the particle size of the powder used is matched with the processing method, thereby obtaining the best processing effect.

[0014] Furthermore, the use of the alloy SnSb12Cu6Zn when coated without grain refiners is advantageous, and in a further advantageous variant it is provided according to the invention that the alloy and / or the material has a reduced proportion of grain refiners or is free of grain refiners.

[0015] For these alloys, there is the possibility of modifying the powders by the optional, selective omission of grain refiners, such as silver, in order to be able to produce good effects and structural layers for laser-based coating methods using their characteristic fast cooling rates, which are necessary due to the process-safe effect of the slower cooling rate of the grain refiners on the casting process. Substituting or omitting the grain refiners would bring considerable economic advantages.

[0016] In a preferred embodiment of the present invention, the powder or compacted powder is manufactured by one of the atomization methods gas atomization, water atomization, gas / water mixed atomization or by a powder production method such as plasma rotating electrode process (PREP) or a powder production process based on friction power.

[0017] Furthermore, according to the invention, a method for manufacturing a sliding layer of a sliding bearing is proposed, using an alloy and / or material according to the above characteristics on a substrate by a laser-based coating method. The alloy and / or material for coating application is in the form of a powder or compacted powder or in the form of a wire.

[0018] Significant advantages can be exploited in product manufacturing through the reverse coating strategy. The microporous-free cast substrate, which is later used as a functional layer (sliding / anti-wear layer), can be coated with any material combination. In this way, components can be produced that require less energy density in the manufacturing process and, if necessary, can be manufactured faster and therefore more cost-effectively.

[0019] The production method is preferably carried out by means of a laser-based coating method, which is laser powder deposition welding or laser wire welding.

[0020] In another advantageous variant, the invention provides that the coating is a sliding layer or an anti-wear layer and is applied to the base body with a thickness of 0.1 mm-10 mm. It is advantageous if the thickness of the sliding layer varies and is adapted to the respective application.

[0021] It is further advantageous if the coating is produced as a multilayer system and comprises a single or multilayer buffer layer made of other materials. This has the advantage that the material properties of the coating can be further adapted to the respective application and optimized for it.

[0022] In an alternative embodiment of the present production method, it is also provided that the CuSn12Ni2 is comminuted and applied in a laser-based method in powder form, if applicable also in wire form, wherein a preheating and / or postheating process is used. Since this material is currently only cast in a conventional manner and is therefore not available, a new powder for coating is produced which, due to the above-mentioned characteristics, has very good material properties for the sliding layer of the sliding bearing.

[0023] In one embodiment of the present invention, it is provided that the base body is made of the alloy additive material group tin and aluminum bronze and other aluminum alloys. Therefore, the bonding of the alloy and / or material to the base body is further improved.

[0024] In a preferred embodiment of the invention, the substrate is manufactured by means of a casting process or by additive manufacturing, and in an advantageous embodiment of the invention it is provided that the substrate has a flat, cylindrical, convex or concave structure, including the possibility of realizing an internal coating or an external coating. After their manufacturing process, these substrates can be coated on one or more sides and inside and outside with the same or different metals (ferrous and non-ferrous) and / or non-metallic powders with a particle size difference of 1 micron-250 microns, if necessary, using one or more buffer layers also consisting of any material system, by means of laser powder cladding or laser wire welding. Multilayers can be realized here.

Claims

1. Use of a material for producing a sliding layer of a hydrodynamic sliding bearing by a method for laser-based coating of the material onto a substrate, wherein the material for coating application is in the form of a powder or compacted powder or in the form of a wire, wherein the material is a tin-based alloy with a proportion of 11% to 14% antimony, 5% to 7% copper, 0.1% to 3% bismuth, 0.1% to 2% zinc and 0.01% to 0.5% tellurium.

2. The use according to claim 1, wherein The powder has a powder grain boundary / particle size of 1 μm to 250 μm.

3. The use according to claim 1 or 2, wherein The material is free of particle size refiners.

4. The use according to claim 1 or 2, wherein the powder or compacted powder is produced by a powder production method selected from the group consisting of gas atomization, water atomization, gas / water mixed atomization, plasma rotating electrode process and powder production process based on friction power.

5. A method for producing a sliding layer of a hydrodynamic sliding bearing on a substrate using a material by means of a laser-based coating method, wherein the material used for coating is in the form of a powder, a compacted powder or a wire, wherein the material is a tin-based alloy with a proportion of 11%-14% antimony, 5%-7% copper, 0.1%-3% bismuth, 0.1%-2% zinc and 0.01%-0.5% tellurium.

6. The method for manufacturing a sliding layer of a fluid dynamic sliding bearing according to claim 5, wherein: The laser-based coating method is laser powder cladding or laser wire welding.

7. The method for manufacturing a sliding layer of a fluid dynamic sliding bearing according to claim 5 or 6, wherein: The applied layer is a sliding layer or an anti-wear layer, and is applied on the substrate in a thickness of 0.1 mm to 10 mm.

8. The method for manufacturing a sliding layer of a fluid dynamic sliding bearing according to claim 5 or 6, wherein: The applied layers are produced as multilayer systems and include single or multilayer buffer layers made of other materials.

9. The method for manufacturing a sliding layer of a fluid dynamic sliding bearing according to claim 5 or 6, wherein: The base body is made of the alloy addition material group tin bronze, aluminum bronze and aluminum alloy.

10. The method for manufacturing a sliding layer of a fluid dynamic sliding bearing according to claim 5 or 6, wherein: The base body is produced by means of a casting process or by additive manufacturing.

11. The method for manufacturing a sliding layer of a fluid dynamic sliding bearing according to claim 5 or 6, wherein: The base body has a flat, cylindrical, convex or concave structure.