Use of a phosphorus-containing bronze alloy for producing a sliding layer on a metal substrate by means of deposition welding

Abstract

The invention relates to the use of a phosphorous-containing bronze alloy for producing a sliding layer on a metal substrate by means of deposition welding.

Description

[0001] Title: Use of a phosphorus-containing bronze alloy for the production of a sliding layer on a metal substrate by means of cladding welding

[0002] Description

[0003] The invention relates to the production of a sliding layer made of a bronze alloy on a metal substrate by means of cladding welding.

[0004] Sliding layers made of bronze alloys are known in many ways from the prior art and are used particularly in plain bearings. For this purpose, it is known to sprinkle the bronze alloy in powder form onto a metal substrate and then sinter it. The metal substrate with the sintered sliding layer can then, for example, be shrunk or pressed onto an axle or shaft in the form of a plain bearing bushing.

[0005] It is also known to apply a sliding bearing material directly to an axle or shaft by means of weld overlay. For example, WO 2019 / 178630 A discloses a wind turbine gearbox in which a sliding bearing material is applied to an axle by means of weld overlay.

[0006] From DE 10 2017 129 361 Al a method for manufacturing a sliding bearing is also known, wherein a bearing layer made of a high-lead tin bronze is applied to a lead-containing buffer layer by means of overlay welding, wherein the bearing layer has 0.1-2% phosphorus.

[0007] However, in the case of welded sliding layers, there is a need for improvement with regard to the load-bearing capacity and durability of the sliding layer.

[0008] The invention addresses the problem of providing sliding layers with high load-bearing capacity and durability in a simple and economical way.

[0009] This problem is solved according to the invention by using the features of claim 1.

[0010] The use of 0.02 - 0.1 wt.% phosphorus as an alloying element of a bronze alloy, in particular a lead-free and silver-free bronze, especially a tin bronze, an aluminum bronze or a manganese bronze, is proposed for the production of a sliding layer on a metal substrate by means of overlay welding of this bronze alloy.

[0011] In particular, the use of a bronze alloy, especially a lead-free and silver-free bronze alloy, in particular a tin bronze, an aluminum bronze or a manganese bronze, for the production of a sliding layer on a metal substrate is proposed by applying this bronze alloy to the metal substrate by means of cladding welding, in particular high-speed laser cladding welding, wherein the bronze alloy contains 0.02 - 0.1 wt.% phosphorus.

[0012] A sliding layer produced in this way from a welded-on phosphorus-containing bronze alloy exhibits high load-bearing capacity and durability. It has surprisingly been found within the scope of the invention that the use of phosphorus in the claimed area results in a particularly homogeneous layer formation during the weld overlay. This is attributed to the fact that the use of phosphorus improves the wetting of the surface of the metal substrate by the molten metal bath formed during the weld overlay. Homogeneous layer formation is particularly advantageous for multilayer coatings, since irregularities in the layer morphology can lead to pores and thus reduced load-bearing capacity.

[0013] Within the scope of the invention, it has been found in particular that the use of phosphorus allows homogeneous layers to be achieved even at high welding speeds of over 50 m / min, especially over 100 m / min – which is often associated with difficulties, as the formation of the molten pool is hampered by the short time. Overlay welding at welding speeds above 50 m / min (also referred to as high-speed (laser) overlay welding) has again proven advantageous in significantly reducing brazing cracks (the risk of embrittlement and cracking upon contact of a wetting metal melt with a metallic component), which has a positive effect on fatigue strength.It has been found that using high-speed cladding welding does not affect the material properties of the metal substrate, or only to a minimal extent, while simultaneously achieving good adhesion of the sliding layer to the metal substrate. This is attributed to the fact that, when cladding at high welding speeds, only a comparatively shallow weld pool is provided directly on the metal substrate, thus reducing the melting energy supplied at the surface of the metal substrate.

[0014] Therefore, it is preferred if the cladding process, in particular laser cladding, is carried out at welding speeds of at least 50 m / min, more preferably at least 100 m / min, and further preferably 50–300 m / min. It proves particularly advantageous if the bronze alloy is cladding using high-speed laser cladding (i.e., laser cladding at welding speeds of at least 50 m / min).

[0015] It has proven particularly advantageous for the bronze alloy to contain 0.025–0.08 wt.%, especially 0.025–0.06 wt.%, of phosphorus. If the phosphorus content is too low, the effects mentioned above are not achieved or are insufficient. Conversely, an excessively high phosphorus content can negatively affect solder cracking.

[0016] A particularly advantageous tin bronze consists of

[0017] 6.0 to 15.0 wt.%, in particular 8.0 - 12.0 wt.%, tin 0.02 - 0.1 wt.%, in particular 0.025 - 0.08 wt.%, further in particular 0.025-0.06 wt.%, phosphorus;

[0018] - possibly bismuth up to 8.0 wt.%

[0019] - possibly zinc up to 4.0 wt.%

[0020] - possibly nickel up to 3.0 wt.%

[0021] - if applicable, sulfur up to 0.8 wt.%; - if applicable, unavoidable impurities up to a maximum of 0.10 wt.% each and in total up to a maximum of 0.5 wt.%;

[0022] - Remaining copper.

[0023] The tin bronze is preferably selected from the group consisting of:

[0024] - CuSn12Ni2, optionally comprising less than 0.8 wt.% sulfur, (i.e. an alloy consisting of 11-13 wt.% Sn, 1.5-2.5 wt.% Ni, optionally up to 0.8 wt.% sulfur, balance copper and unavoidable impurities)

[0025] - CuSn12Bi3Ni2 (i.e. an alloy consisting of 11-13 wt.% Sn, 2-4 wt.% Bi, 1.5-2.5 wt.% Ni, balance copper and unavoidable impurities)

[0026] - CuNil5Sn8 (i.e. an alloy consisting of 13-16 wt% Ni, 7-9 wt% Sn, balance copper and unavoidable impurities)

[0027] - CuNil5Sn8Bi4 (i.e. an alloy consisting of 13-16 wt.% Ni, 7-9 wt.% Sn, 2-6 wt.% Bi, balance copper and unavoidable impurities)

[0028] - CuSnl4 (i.e. an alloy consisting of 13-15 wt% Sn, the remainder copper and unavoidable impurities)

[0029] - CuSnlOBi7Zn3 (i.e. an alloy consisting of 9-11 wt.% Sn; 6-8 wt.% Bi; 0-4 wt.% Zn, balance copper and unavoidable impurities)

[0030] - CuSn7 , 5Bi3 , 5Zn2 (i.e. an alloy consisting of 7-8 wt.% Zn; 3-4 wt.% Bi; 0-2 wt.% Zn, balance copper and unavoidable impurities)

[0031] - CuSnIBi3,5ZnI,5NI (i.e. an alloy consisting of 10-12 wt.% Sn; 3-4 wt.% Bi; 0-2 wt.% Zn; 0.5-1.5 wt.% Ni, balance copper and unavoidable

[0032] (Impurities). A particularly advantageous aluminum bronze consists of

[0033] 6.0 to 12.0 wt.% aluminum, 0.02 - 0.1 wt.%, in particular 0.025 - 0.08 wt.%, further in particular 0.025-0.06 wt.%, phosphorus;

[0034] - any unavoidable impurities up to a maximum of 0.10 wt.% each and a maximum total of 0.5 wt.% ;

[0035] - Remaining copper.

[0036] Preferably, the aluminium bronze is selected from the group consisting of:

[0037] - CuA18 (i.e. an alloy consisting of 7-9 wt% Al, the remainder copper and unavoidable impurities)

[0038] - CuAllO, optionally also containing iron up to 5.0 wt.% and / or nickel up to 5.0 wt.% (i.e. an alloy consisting of 9-11 wt.% Al, optionally up to 5.0 wt.% iron, optionally up to 5.0 wt.% nickel, balance copper and unavoidable impurities).

[0039] An advantageous manganese bronze consists of:

[0040] - 2.0 - 20.0 wt.%, in particular 13.0 - 15.0 wt.%, manganese

[0041] - possibly iron up to 5.0 wt.%

[0042] - possibly nickel up to 5.0 wt.%

[0043] - possibly bismuth (Wismut) up to 10.0 wt.%

[0044] - any unavoidable impurities up to a maximum of 0.10 wt.% each and a total of no more than 0.5 wt.% . ;

[0045] - The remainder is copper. Preferably, the manganese bronze is a CuMnI4Fel alloy, meaning it consists of:

[0046] 13.0 - 15.0 wt% manganese

[0047] 0.5 - 1.5 wt.% iron

[0048] - any unavoidable impurities up to a maximum of 0.10 wt.% each and a total of no more than 0.5 wt.% . ;

[0049] - Remaining copper.

[0050] The bronze alloy can be in the form of a powder or a

[0051] The powder mixture is present. Then the application of the

[0052] Bronze alloy, in particular by means of

[0053] Las erpul contract welding is carried out.

[0054] The bronze alloy can also be in wire form. In this case, the application of the bronze alloy can be carried out, in particular, by laser wire welding.

[0055] In a further advantageous development, the bronze alloy can be part of a coating material which is applied to the metal substrate by weld overlay to produce the sliding layer. In addition to the bronze alloy, the coating material can contain up to 5.0 wt.% additives, in particular fillers. The additives are preferably selected from the group comprising BN, WC, SiC, TiC, and Cr3C2.

[0056] In this respect, another aspect of the disclosure relates to the use of an additive material for producing a sliding layer on a metal substrate by applying this additive material to the metal substrate by means of additive welding, in particular high-speed welding.

[0057] Laser cladding, wherein the cladding material comprises:

[0058] - a bronze alloy, in particular a lead-free and silver-free bronze alloy, especially a tin bronze, an aluminum bronze or a manganese bronze, wherein the bronze alloy contains 0.02 - 0.1 wt.% phosphorus, and

[0059] - Additives, in particular up to 5.0 wt.%, further in particular selected from the group comprising BN, WC, SiC, TiC, and Cr3C2.

[0060] Another aspect concerns a method for producing a sliding component, comprising a metal substrate and a sliding layer applied thereto, using a bronze alloy or a coating material described above by means of overlay welding of this bronze alloy or coating material onto the metal substrate to form the sliding layer.

[0061] Therefore, a method for producing a sliding component, comprising a metal substrate and a sliding layer applied thereto, is further proposed, the method comprising:

[0062] - Providing the metal substrate;

[0063] - Providing a material for the application;

[0064] - Applying the coating material to at least one section of the metal substrate by means of cladding welding, in particular laser cladding welding, further in particular high-speed laser cladding welding, wherein the coating material comprises or consists of a bronze alloy, in particular a tin bronze, an aluminum bronze or a manganese bronze, wherein the bronze alloy contains 0.02 - 0.1 wt.%, in particular 0.025 - 0.08 wt.%, further in particular 0.025-0.06 wt.%, phosphorus.

[0065] As mentioned above, the coating material may contain up to 5.0 wt.% additives, in particular fillers, in addition to the bronze alloy.

[0066] Preferably, the application of the sliding layer comprises the sequential application of at least five, preferably at least ten, and more preferably at least twenty, layers of the bronze alloy or the coating material one on top of the other. In this respect, at least five, preferably at least ten, and more preferably at least twenty, layers of material are preferably applied sequentially to the metal substrate. In other words, the material layers are applied radially to one another. The material layers together form the sliding layer. In this way, only a comparatively shallow melt pool is provided directly on the metal substrate during application, thus further reducing the melting energy supplied directly at the surface of the metal substrate and, consequently, the influence on the material of the metal substrate. The material layers are, for example, visible under a light microscope in a micrograph.

[0067] Furthermore, it proves advantageous if the application of the material layers is carried out in such a way that the layer thickness of a base layer of the at least five material layers closest to the metal substrate is a maximum of 50 pm, in particular a maximum of 30 pm, further in particular a maximum of 20 pm, further in particular a maximum of 10 pm, further in particular a maximum of 5 pm, in particular from 5 to 50 pm.

[0068] As mentioned above, it proves advantageous if the application of the coating material is carried out by means of high-speed laser cladding with a welding speed of over 50 m / min.

[0069] A sliding component is also proposed, comprising a metal substrate and a sliding layer applied thereto by weld overlay. The sliding layer is formed from a weld overlay material. The weld overlay material comprises or consists of a bronze alloy as described above. Specifically, the weld overlay material comprises (or consists of) a bronze alloy, in particular lead-free and silver-free, especially tin bronze, aluminum bronze, or manganese bronze, wherein the bronze alloy contains 0.02–0.1 wt.%, in particular 0.025–0.08 wt.%, and further in particular 0.025–0.06 wt.%, phosphorus.

[0070] For example, the sliding component could be a shaft or axle of a plain bearing. The sliding component could also be, for example, a plain bearing shell. The sliding component could also be, for example, a thrust washer or thrust ring. The sliding component could also be, for example, a control disc, e.g., for rotary piston pumps. The sliding component could also be, for example, a projectile. The sliding layer could then, for example, form a guide band for the projectile. An advantageous tin bronze for the sliding layer of the

[0071] The sliding component consists of:

[0072] 6.0 to 15.0 wt.% tin, in particular 8.0 - 12.0 wt.%; 0.02 - 0.1 wt.% phosphorus, in particular 0.025 - 0.08 wt.%, further in particular 0.025-0.06 wt.%;

[0073] - possibly bismuth up to 8% by weight

[0074] - possibly zinc up to 4% by weight

[0075] - possibly nickel up to 3% by weight

[0076] - possibly sulfur up to 0.8 wt.%;

[0077] - if applicable, impurity-related elements up to a maximum of 0.10 wt.% each and a maximum of 0.5 wt.% in total.

[0078] - Remaining copper.

[0079] In particular, the tin bronze can be used in the sliding layer of the

[0080] The sliding component must be selected from the group consisting of:

[0081] - CuSnl2Ni2, optionally comprising less than 0.8 wt% sulfur ,

[0082] - CuSnl2Bi3Ni2,

[0083] - CuNil5Sn8,

[0084] - CuNil5Sn8Bi4,

[0085] - CuSnl4,

[0086] - CuSnl 0Bi7Zn3 ,

[0087] - CuSn7 , 5Bi3 , 5Zn2 ,

[0088] - CuSnllBi3, 5Znl, 5Nil .

[0089] An advantageous aluminum bronze for the sliding layer of the

[0090] The sliding component consists of:

[0091] - 7.0 to 12.0 wt.% aluminum

[0092] 0.02 - 0.1 wt.% phosphorus, in particular 0.025 - 0.08 wt.%

[0093] %, furthermore in particular 0.025-0.06 wt.%; - any unavoidable impurities up to a maximum of 0.10 wt.% each and in total up to a maximum of 0.5 wt.% ;

[0094] - Remaining copper.

[0095] In particular, the aluminium bronze can be selected from the group consisting of:

[0096] CuA18

[0097] CuAllO, optionally also containing iron up to 5 wt.% and / or nickel up to 5 wt.%.

[0098] An advantageous manganese bronze for the sliding layer of the sliding component consists of:

[0099] - 2.0 - 20.0 wt.%, in particular 13.0 - 15.0 wt.%, manganese

[0100] - possibly iron up to 5.0 wt.%

[0101] - possibly nickel up to 5.0 wt.%

[0102] - possibly bismuth (Wismut) up to 10.0 wt.%

[0103] - any unavoidable impurities up to a maximum of 0.10 wt.% each and a maximum total of 0.5 wt.% ;

[0104] - Remaining copper.

[0105] Preferably, the manganese bronze of the sliding layer is used.

[0106] The sliding component is a CuMnl4Fel alloy, and therefore consists of:

[0107] 13.0 - 15.0 wt% manganese

[0108] 0.5 - 1.5 wt.% iron

[0109] - any unavoidable impurities up to a maximum of 0.10 wt.% each and a total of no more than 0.5 wt.% . ;

[0110] - Remaining copper. Preferably, the sliding layer of the sliding component comprises at least five, preferably at least ten, further preferably at least twenty, superimposed layers of the welded-on material. In particular, a base layer of the at least five material layers closest to the metal substrate has a layer thickness of at most 50 pm, in particular at most 30 pm, further in particular at most 20 pm, further in particular at most 10 pm, further in particular at most 5 pm, in particular from 5 to 50 pm.

[0111] The sliding layer of the sliding component can optionally also contain up to 5.0 wt.% fillers. In particular, the fillers are selected from the group comprising BN, WC, SiC, TiC, and Cr3C2.

[0112] The advantages and optional features explained above with regard to use and manufacturing processes can also be used to design the sliding component, so reference is made to the above disclosure to avoid repetition.

[0113] Definitions and general aspects:

[0114] The metal substrate can take various forms. Examples include a sheet, a shaft, an axle, a disc, or the body of a projectile. The metal substrate can be made of metal or a metal alloy.

[0115] In the present context, "lead-free" means that lead is not actively added as an alloying element and that any residual lead due to impurities is at most 0.10 wt.%, in particular at most 0.09 wt.%, in particular at most 0.08 wt.%, in particular at most 0.07 wt.%, in particular at most 0.06 wt.% and preferably at most 0.05 wt.%.

[0116] In the present context, "silver-free" means that silver is not actively added as an alloying element and that any residual silver due to impurities is at most 0.10 wt.%, in particular at most 0.09 wt.%, in particular at most 0.08 wt.%, in particular at most 0.07 wt.%, in particular at most 0.06 wt.% and preferably at most 0.05 wt.%.

[0117] In the present context, "tin bronze" refers to a copper-tin alloy.

[0118] In the present context, "aluminium bronze" refers to a copper-aluminium alloy.

[0119] In the present context, "manganese bronze" refers to a copper-manganese alloy.

[0120] In this context, cladding (sometimes also referred to as surfacing according to DIN 8580) is understood to be a process in which a surface coating is applied to a substrate by melting a coating material using a heat source, with simultaneous or subsequent application to the substrate surface. The coating material, in this context, refers specifically to the starting material that is fed to the heat source for melting. The coating material can be in powder form, e.g., as metal powder, or also as wire or strip.

[0121] According to one exemplary implementation of cladding, the material to be deposited (bronze alloy or other coating material) is melted or fused in the focus of a laser beam and then deposited. In particular, the material to be deposited is provided as a powder or wire, which is melted or fused in the focus of the laser beam and then deposited. Specifically, the focus and the metal substrate are displaced relative to each other at a speed of at least 50 m / min, preferably at least 100 m / min, and more preferably 50–300 m / min.

[0122] Preferably, the application of at least one coating material is carried out by means of laser cladding. In this context, laser cladding is understood to mean, in particular, cladding welding in which a laser serves as a heat source for melting the coating material, here the bronze alloy.

[0123] In this context, high-speed laser cladding is understood to mean laser cladding with a welding speed of more than 50 m / min.

[0124] In this context, "welding speed" is understood to be the relative speed of the heat source, in particular a laser, and the metal substrate parallel to a surface of the metal substrate. In this context, "cladding welded" refers to...

[0125] The term "material" refers to the bronze alloy applied and solidified by overlay welding, or the overlay material applied and solidified by overlay welding. A typical characteristic that arises during overlay welding is...

[0126] The material structure can be identified, for example, in the polished section (e.g., after metallographic etching in a light microscope) and thus distinguished by the expert from other processes, such as thermal spraying or vapor deposition (PVD or CVD processes).

[0127] In the present context, "layer thickness" is understood in particular to mean an average layer thickness orthogonal to a surface of the metal substrate.

Claims

Patent claims 1. Use of a lead-free, in particular silver-free, bronze alloy, in particular a tin bronze, an aluminum bronze or a manganese bronze, for the production of a sliding layer on a metal substrate by means of cladding, in particular high-speed laser cladding, of this bronze alloy, wherein the bronze alloy contains 0.02 - 0.1 wt.% phosphorus.

2. Use according to claim 1, wherein the bronze alloy contains 0.025 - 0.08 wt.%, in particular 0.025-0.06 wt.%, phosphorus.

3. Use according to claim 1 or 2, wherein the tin bronze consists of 6.0 to 15.0 wt.% tin, in particular 8.0 - 12.0 wt.% 0.02 - 0.1 wt.% phosphorus, in particular 0.025 - 0.08 wt.%, further in particular 0.025-0.06 wt.%; - possibly bismuth up to 8.0 wt.% - possibly zinc up to 4.0 wt.% - possibly nickel up to 3.0 wt.% - possibly sulfur up to 0.8 wt.%; - any unavoidable impurities up to a maximum of 0.10 wt.% each and a maximum total of 0.5 wt.% ; - Remaining copper.

4. Use according to any of the preceding claims, wherein the tin bronze is selected from the group consisting of: - CuSnl2Ni2, optionally comprising less than 0.8 wt% sulfur , - CuSnl2Bi3Ni2, - CuNil5Sn8, - CuNil5Sn8Bi4, - CuSnl4, - CuSnl 0Bi7Zn3 , - CuSn7 , 5Bi3 , 5Zn2 , - CuSnllBi3, 5Znl, 5Nil .

5. Use according to any of the preceding claims, wherein the aluminium bronze consists of 6.0 to 12.0 wt.% aluminium; 0.02 - 0.1 wt.% phosphorus, in particular 0.025 - 0.08 wt.%, further in particular 0.025-0.06 wt.%; - any unavoidable impurities up to a maximum of 0.10 wt.% each and a maximum total of 0.5 wt.% ; - Remaining copper.

6. Use according to any of the preceding claims, wherein the aluminium bronze is selected from the group consisting of: - CuAl 8 - CuAllO, optionally also containing iron up to 5.0 wt.% and / or nickel up to 5.0 wt.%.

7. Use according to any of the preceding claims, wherein the bronze alloy is in the form of a powder or wire.

8. Use according to any of the preceding claims, wherein the bronze alloy is part of an aggregate material used to produce the sliding layer by means of The material is applied to the metal substrate by overlay welding, whereby the overlay material is, apart from the Bronze alloy comprising up to 5.0 wt.% additives, wherein the additives are selected from the group comprising BN, WC, SiC, TiC, and Cr3C2.

9. Method for producing a sliding component comprising a metal substrate and a sliding layer applied thereto, using a bronze alloy or a coating material according to any of the preceding claims, by means of overlay welding the bronze alloy or the coating material onto the metal substrate to form the sliding layer.

10. Method according to the preceding claim, wherein the application of the sliding layer comprises the sequential application of at least five, preferably at least ten, layers of material of the bronze alloy or the coating material on top of each other.

11. Method according to the preceding claim, wherein the application of the material layers is carried out such that the layer thickness of a base layer of the at least five material layers closest to the metal substrate is a maximum of 50 pm.

12. Method according to any one of claims 9 to 11, wherein the application of the coating material is carried out by means of high-speed laser cladding.

13. Sliding component comprising a metal substrate and a sliding layer applied thereto, characterized in that the sliding layer is made of a welded-on material. is formed, wherein the welded material consists of or comprises a bronze alloy as defined in any one of claims 1 to 8.

14. Sliding component according to the preceding claim, wherein the sliding layer comprises at least five, preferably at least ten, layers of material applied to one another from the welded-on material.

15. Sliding component according to the preceding claim, wherein a base layer of the at least ten material layers closest to the metal substrate has a layer thickness of at most 50 pm, in particular at most 30 pm, further in particular at most 20 pm, further in particular at most 10 pm, further in particular at most 5 pm, in particular from 5 to 50 pm.

16. Sliding component according to one of claims 13 to 15, wherein the sliding layer further comprises up to 5.0 wt.% fillers, wherein the fillers are selected from the group comprising BN, WC, SiC, TiC, and Cr3C2.