DE7918966U1 - Tribological workpiece, for example plain bearings with an adaptation layer for loads with extremely high surface pressure - Google Patents

Description

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Dipl.-Phys. Heinrich Seids · Patent attorney ■ Bierstadter Höhe 15 · PO Box 5105 ■ 6200 Wiesbaden 1 · ® (06121) 562022

- 4 - Wiesbaden, July 1st, 1980 G 519 ud / ha

Glyco-metal works
Daelen & Loos GmbH
Stielstrasse 11
6200 Wiesbaden

Tibological workpiece, for example a slide bearing with an adaptation layer for stress with extremely high surface pressure

The invention relates to a texibological workpiece, For example, plain bearings with an adaptation layer for loads with extremely high surface pressure and / or or friction or wear and / or high temperature on its sliding surface.

The basic meaning of the present invention is given below using the example of slide bearing elements presented as a tribological workpiece.

Each time a hydrodynamically lubricated bearing is started or shut down, the zone the mixed friction passed. This leads to direct partial contact between the plain bearing material and shaft material. This creates dependency

Dipl.-Phys. Heinrich Seids · Patent Attorney ■ Bierstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 · ® * (0 6121) 56 20 22

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the stress a more or less severe wear of the mating partner. In the case of plain bearings, there is usually an adjustment process necessary in order to adjust the micro-geometries with new, virgin bearing pairings between the shaft and the bearing, i.e. the roughness peaks resulting from machining in the interfaces or to smooth the geometric inaccuracies through programmed wear and thus the contact area of the tribological workpiece, e.g. the sliding element, and thus the permissible mechanical load limit to increase. The time required for this process has so far mainly been dependent on the properties of the Tribosystems sliding bearing material / lubricant / shaft mechanism to f | f addicted. By using galvanic coatings for heavy-duty, ready-to-install bearing shells for Internal combustion engines, so-called three-fuel bearings, are Preventive adjustment processes, e.g. for engines in the car industry, are practically no longer necessary, whereas with diesel engines in the range from 370 to 1580 kW, the adjustment time can be reduced from 20 to 30 to 2 to 5 hours could. In the case of three-component bearings, a base layer of the basic plain bearing material is usually used, consisting e.g. of copper or aluminum alloy material, a ductile galvanic coating in one layer thickness from 0.015 to 0.O4O min usually galvanized, i.e. without repeated subsequent mechanical processing,

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'Dlpl.-Phys. Heinrich Seids. Patent attorney · Bierstadter Höhe IS. P.O. Box SlOS · 6200 Wiesbaden i ■ <S "(0 6121) do 20 22

upset.

The adaptability of the relatively soft, ductile electroplated layer favors the adaptation process and increases it both the resistance of the plain bearing to welding with the shaft and the wettability with Lubricants. The galvanic coatings consist either of lead-i-indium, lead-tin or lead-tin-copper. In the case of the latter, alloys with increased copper contents of up to 10% by mass have recently become known (DE-OS 27 22 144). The demands made by engine manufacturers for increased load capacity and fatigue strength as well as wear resistance and corrosion resistance have added to these newer galvanic Layers led, however, due to their higher hardness, the conditions for the effectiveness of the adjustment process no longer fully satisfactory. This is attempted by adding EP additives to the lubricating oil to come closer, whereby the removal of roughness peaks by a linked chemical-mechanical VOi is effected. Partial contact during the

! Adjustment process to a certain extent creates pressure peaks j and temperature peaks that lead to a chemical reaction | the aggressive active ingredients of the additives with the Materials of the bearing with the formation of e.g. metal sulphides, chlorides and phosphates, whereby reinforced

Formation of Ad leading to welding and thus material fatigue due to heights is avoided. It was observed that
conversion of the sliding material surface,
made of Pb-Sn-Cu! Electroplating layers adjustment phase - depending on the type and size of the operating conditions of the motors (long, short-distance travel and corresponding temperatures are unevenly distributed over the storage meta and also run unk over time, which can of course lead to operational disruptions.

In DE-OS 28 40 425 it is the task of the improved adaptation layers for e.g. to create required elements, in particular on herköi schichtgleitelemente.

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Diploma in Phys. Heinrich Seids patent attorney Bierstadter Höhe 15. P.O. Box 5105 6200 Wissbaden 1

(0 6121) 56 20

The solution to this problem mentioned in DE-OS 2 8 40 425 is achieved in that the adaptation layer is a closed, continuous reaction layer based on dry friction and welding of metal surfaces preventive metal salts through controlled, preventive chemical conversion of the workpiece surface using Such wear and corrosion-inhibiting high-pressure additives are generated, which in themselves are only used in operational Use of additives or inhibitors that become partially effective under the effect of increased pressure and temperature in natural and synthetic lubricants or emulsions to reduce friction, wear, Temperature and corrosion are known.

Furthermore, it is the further task according to DE-OS 28 40 425 workpieces, in particular slide bearing elements to create that are equipped with such an adaptation layer with significantly improved properties. This is achieved in that the workpiece is exposed to wear and tear under relatively high surface pressure and / or or increased friction and / or increased temperature exposed surface a closed, continuous Bears a reaction layer of high shear strength in the form of metal chlorides, metal phosphates and / or metal sulfides, prevents dry friction and welding on metal surfaces.

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Dipl.-Phys. Heinridi Seids · Patent Attorney. Bierstadter Höhe IS · P.O. Box 5105 · 620C Wiesbaden 1 · ® (0 6121) 562022

The tribological workpiece can preferably be a sliding bearing element, the sliding layer of which is made up of a white metal alloy increased copper content or by a hard nickel-tin alloy or by one for segregation suspension alloy, for example an aluminum-lead suspension alloy is formed. With such workpieces there is a uniform, closed, Protective insulating layer formed to reduce wear and temperature as well as to Increase in fatigue strength as well as corrosion resistance. This makes such workpieces suitable Significantly higher loads, especially in the area of mixed rubbing, without complications.

10

15th

20th

The time required to produce the layers is, however, considerable and, up to now, has not been incorporated into an automatic process insert.

In contrast, it is the object of the present invention to provide adaptation layers for e.g. Elements, especially conventional multilayer sliding elements, with at least the same good properties as known from DE-OS 28 40 425 to create, which in a relatively short time unit of e.g. one to two minutes - depending on the current density and bath concentration, the coating process is

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Dipl.-Phys. Heinrich Seids · Patent Attorney. Bierstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 - §? (0 6121) 56 20

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NEN electroplating machines can be inserted.

The object is achieved according to the invention in that the adaptation layer is more uniform, more micro-cracked (Mosaic-like) coating on the basis of preventing dry friction and wear of metal surfaces Oxides of the metal molybdenum formed by a typical one for formation by means of an electrochemical process Structure with the sliding surface as a basis on this is bound.

It has surprisingly been shown that tribological workpieces, in particular conventional sliding bearing elements coated with this coating of oxides of molybdenum according to the invention, significantly better properties have, as previously known in plain bearing technology.

The inventive measure creates a plain bearing element, for example, which is _{far superior to the so-called three-substance bearings with an improved adaptation layer, which has been considered to be conventional and C 1} I - optimal technical solution up to now, in particular with regard to reducing wear and temperature as well as increasing fatigue strength and corrosion resistance .

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DlpL-Phys. Heinrich Seids. Patent attorney. Blerstadter Höhe 15 · P.O. Box 5105 ■ 6200 Wiesbaden 1. ® * (0 6121) 56 20

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Systematic series tests on plain bearings have shown, among other things, that with electro-chemical Coating with oxides of molybdenum from conventional so-called three-material plain bearings as well as the long-term load capacity Surprisingly, they can be positively influenced.

In a particularly advantageous manner, the adaptation layer ^ which is anchored to the base metal, in a thickness between 0.5 µm and 3 µm, preferably 1 µm be.

In a particularly advantageous manner, the structure of the adaptation layer can be achieved by cathodic electrolysis be formed structure. In a further advantageous manner, a base layer made of a nickel-tin alloy with a tin content between about 30 and 90% by weight and with a maximum thickness of 0.1 mm, preferably 0.005 mm to 0.015 mm, thick sliding layer on bearing material with a Brinell hardness between approx. 4 and 30 are covered, and over this sliding layer a uniform, micro-cracked (mosaic-like) adaptation layer be arranged from oxides of the metal molybdenum. In a particularly advantageous manner, the tribological workpiece be designed in the form of a sliding bearing element, in which the sliding layer carrying the adaptation layer of the plain bearing element made of a bearing alloy with 10 to 20% tin, 6 to 10% copper, the remainder lead, in particular

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Dipl.-Phys. Heinrich Seids · Patent Attorney · Blerstadter Höhe 15 · PO Box 5105 · 6200 Wiesbaden 1 ■ S? (06121) 562022

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16% tin, 8% copper, the remainder lead. The tribological workpiece can be in the form of a sliding bearing element in which the sliding layer carrying the adaptation layer is formed by a suspension alloy that tends to separate, in particular one that tends to separate
Aluminum-lead alloy can be formed.

Although the following example primarily relates to a selected, conventional, multi-layer sliding bearing element, it goes without saying that other embodiments for sliding bearing elements with regard to the production of wear, temperature and
corrosion-inhibiting layers as well as for others
Metallic elements that are highly stressed to friction as the plain bearings described according to the extraordinary, simple, inexpensive treatment method in the frame
of the invention are possible, such as on bearing journals,
Pistons, cylinder walls, guides, roller bodies, tool surfaces, tooth flanks of gear wheels, valve guides, piston rings, roller and toothed chains, etc.

So-called three-substance bearings with a conventional layer structure :

Steel support body, cast 0.3 mm thick copper-lead alloy - CuPb22Sn - as a base layer, galvanically applied 1.5 in the thick nickel dam as a barrier layer

Dipl.-Phys. Heinrich Seids. Patent attorney ■ Bierstadter Höhe IS · PO Box 5105 · 6200 Wiesbaden 1 ■ ® (06121) 562022

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an approximately 22 .mu.m thick ternary sliding and adaptation layer made of PbSnlOCu2, provided on all sides with a 1 µm thick matching layer made of oxides of molybdenum, produced, for example, within 1 to 2 minutes depending on the current density and concentration of the electrolyte and thus definitely in the production cycle of a machine appropriate. A uniform microporous (mosaic-like) deep black forms on the surface of the plain bearing Adaptation layer.

The tribological workpieces treated according to the invention E.g. plain bearings were tested on a plain bearing test bench subjected. For these tests, the plain bearing halves to be tested are individually placed in the lower part of a two-part Mounted bearing mount. In the upper part of the bearing seat there is a conventional plain bearing shell without inventive aftertreatment built in «To set the test conditions (speed, lubricant temperature, specific plain bearing load or the like) only the upper untreated plain bearing half is statically loaded. A larger bearing play in the sliding bearing half to be tested also ensures that the Tempering the cones does not come into mechanical contact with the test dish. After setting the test conditions the sliding bearing half to be tested is set by changing the load direction via a lever arm on the bearing mount by means of a continuously adjustable hydraulic cylinder

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Dipl.-Phys. Heinrich Seids. Patent attorney Bierstadter Höhe 15 PO Box 5X05 6200 Wiesbaden X ST (06121) 362022

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statically loaded. The lever arm is mounted on points and thus acts as a friction balance at the same time. the The coefficient of friction is determined using a pressure cell.

Test data: SAE 30 (HD) lubricant 5 bar Lubricant inlet pressure 120 ° C Lubricant inlet temperature 0 5 8.6 mm Stock taking Ck 45 HRC 55 Tenon material Ra 0.14-0.18 µm Tenon roughness 54.93 mm Journal diameter 22 mm Plain bearing width 7000 min "= 5.75 m / s Speed (min)

An embodiment of the invention is shown on the basis of the accompanying figures:

1 shows a sliding bearing half according to the invention in a perspective illustration;

Fig. 2 is a section A-B in a preferred embodiment form of the sliding bearing half of FIG. 1, enlarged and in section;

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Diploma in Phys. Heinrich Seids - Patent Attorney - Bieistadter Höhe 15 -Postfach 5105 · 6200 Wiesbaden 1 - & (0 6121) 56 20

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3 shows a schematic representation of the reduction in wall thickness for untreated —a—, improved -b- Gleitiagerhalften and according to the invention coated -c- bearing halves depending on the static load;

4 shows a diagram of the temperature characteristics for -a- and -b- and coated according to the invention -c- Plain bearings depending on the static load measured on the back of the bearing after 15 minutes of operation and

Fig. 5 Comparison of the coefficient of friction characteristics also for -a-, -b- and -c- as a function the static load measured firstly -1- in the virgin state immediately Connection of the load and secondly -2-

after 15 minutes of adjustment time.

In the example of FIGS. 1 and 2, a base layer 4 made of a copper-lead-tin alloy is on a steel support body 5 CuPb22Sn applied with a layer thickness of about 0.2 mm to 0.7 mm. On this base layer 4 is an extremely thin layer 3 (thickness 0.001 to 0.002 mm) made of nickel, which is used in conventional three-substance bearings as Diffusion barrier is used. Over the diffusion barrier is e.g. an approximately 0.022 mm thick ternary smooth and conformal layer 2 from PbSnlOCu2. On the sliding layer 2

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Dipl.-Phys. Heinrich Seids. Patent attorney Bierstadter Höhe 15. P.O. Box 5105 6200 Wiesbaden 1 & (06121) 562022

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and also on the steel support body 5 is initially a 0.0005 to 0.003 mm, preferably 0.001 mm thick adjustment layer from oxides of molybdenum.

Figures 3, 4 and 5 provide a comparison Characteristic curves for changes in wall thickness as well as temperature and friction behavior of the untreated -a- and treated -found -c- plain bearing shells at varying bearing pressures again under resting stress. The diagrams clearly show the superiority of those treated according to the invention -c- plain bearings in terms of maximum load capacity under

above test conditions. The untreated -a-

2.

Plain bearings fail at a bearing pressure of 42 N / mm im In contrast to the treated -b- plain bearings, which

only expose at a bearing pressure of approx. 80 N / mm. Set the -c- plain bearings treated according to the invention

only at a bearing pressure of about 110 N / mm.

Subsequent investigations with practical installation conditions under difficult test conditions, e.g. under changing Loads, speeds, lubricant temperatures, lubricant quantities or lubricant pressure and the like., Showed the advantage of the so-called three-substance bearings treated according to the invention over the conventional known ones Executions. Subsequent tests in high-speed racing engines with turbocharging and fuel injection

Dipl.-Phys. Heinrich Seids · Patent attorney - Bierstadter H8he 15 · Postfadi 5105 · 6200 Wiesbaden 1 - ® (0 6131) 56 20 22

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occurred - in contrast to untreated three-substance bearings without any difficulty.

Subsequent expansion unmistakably showed the advantage of the micro-cracked inventive adaptation layer in terms of surface properties, dimensional accuracy, friction and load capacity compared to a conventional layer structure. Not only plain bearings in solid and / or layered design, also other metallic elements, which are subject to high friction or wear, can be subjected to a similar simple, inexpensive treatment of the surface layer, so that a wear- inhibiting tZfi. high-pressure-resistant and low-friction layer with lubricating properties is formed.

Instead of the structure of slide bearing elements explained above in connection with FIGS. 1 and 2, slide bearing elements are also used with a different structure of the sliding layer for equipping with an adaptation layer according to the invention in Consideration. For example, the sliding layer of a sliding bearing element can consist of one that tends to separate There are suspension alloy, for example, fchermokinetic or also applied by application and mechanically compressed together with the carrier layer. This suspension alloy can preferably be an aluminum-lead suspension. On the surface of such a

Dipl.-Phys. Heinridi Seids - Patent Attorney · Bierstadter Höhe 15 · Postfach 5105 - 6200 Wiesbacfen 1 - S? (0 6121) 562022

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Sliding layer can adjust the adjustment Schxcht in the invention Way to be educated.

Another possible application of the adaptation layer according to the invention can also be found in plain bearing elements whose sliding layer is formed by a white metal alloy

is that as a ternary alloy 10% to 20% tin, 6 to 10% j

i copper, remainder lead, in particular 16% tin, 8% copper, remainder j

Contains lead, the tin always being 6 to 8% larger j

Mass constituent as the copper is supposed to represent. The adaptation layer according to the invention can also be applied to such a sliding layer are formed.

Another possibility of using the inventive Adaptation layer is given with hard, thin layers, for example with such bearing elements thin layer of a hard tin-containing alloy with a layer of softer metallic alloy. Material j is highlighted. In such a case, the layer can be made of a nickel-tin alloy with a tin content between about 3O and 90 wt .-% bascehen and a maximum thickness of about 0.01 mm, preferably about 0.005 to 0.01 mm and with a maximum 0.05 mm, preferably 0.005 to 0.015 mm thick sliding layer made of bearing material of a Brinell hardness between about 4 and 30 must be covered. In this case, too, the

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Dipl.-Fhys. Heinrich Selds ■ patent attorney ■ Bterstadter Höhe 15. P.O. Box 5105 ■ 6200 Wiesbaden 1 · _? (06121) 56 2022

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adaptation layer according to the invention be formed.

As FIGS. 3, 4 and 5 show, the layer according to the invention has a far better running-in and wear behavior than conventional ternary layers. In addition, the time to generate a thickness of 1 pm with 1 to 2 min - depending on the current density and concentration of the electrolyte - fits perfectly into the cycle of a machine. In addition to the task of adapting the micro-geometries of the friction partners in the run-in phase, the oxidic layers have an advantageous effect in the mixed area and reduce wear considerably. In addition, it has been shown that they also have an all-round anti-corrosion function. Fingerprints are not visible, as is usually the case with ternary sliding layers, nor do black spots from basic sulfides of lead appear when bearing shells are stored for a long period of time. The layer according to the invention thus has a polyfunctional effect.

With the help of X-ray diffraction, the following oxides of molybdenum are produced in the electrochemically generated layers, depending on Test conditions, determined:

Dlpl.-Phys. Heiniich Solds · Patent Attorney · Bierstadter Höhe 15 ■ Postfach 5105 · 6200 Wiesbaden 1 · GF (06121) 562022

Ι) MO ₅ Og (OH) ₈ 4)

2) MoO (OH) ₃ 5)

3) Mo ₄ O ₁₁ 6)

The best and most uniform oxide layers that are firmly anchored to the base metal are derived from the following obtained electrolytes listed under the specified] conditions: |

4H ₂ O = 10 to 20 g / l

NH ₄ NO ₃ = 15 to 30 g / lf

i = 1.5 to 2.0 A / dm ²

^ = 35 to 40 ° C

t = 1.5 to 2.0 min

Anode = remanite

pH = 5 to 6

Reaction = cathodic ρ

An inventive adaptation layer through cathodic Electrolysis in an aqueous bath from |

10 g / l ammonium ptamolybdate _{, (NH 4 JgMo 7} O ₂₄ ^ H ₂ O and 15 g / l ammonium nitrate, NH ₄ NO ₃

at -J = 40 ° C

a current density of 2 A / dm for 2 minutes, consists essentially of molybdenum oxide hydroxide

MoO (OH) ₃ . It is designed like a mosaic (micro-cracks) and therefore capillary-active and predominantly X-ray

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Dlpl.-Phys. Heinrich Seids · Patent Attorney ■ Blerstadter Höhe IS. P.O. Box 5105 6200 Wiesbaden 1 ■ & (06121) S62022

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amorphous. The size of the individual "mosaic blocks" is influenced by:

the current density i the temperature.-A the concentration of (NH ₄ JgMo ₇ O ₂₄ MH ₂ O the exposure time t

In addition to these examples, there is the adaptation layer according to the invention and how they are manufactured on practically all known layers of sliding and bearing elements conceivable.

Claims (6)

10 1) Tribological workpiece, for example plain bearings with an adaptation layer for use with extreme high surface pressure and / or friction or wear and / or high temperature on its sliding j j surface, characterized in that the adaptation \ layer (1) (a mosaic) as a uniform, micro-cracking coating on the basis of dry friction and wear of metal surfaces preventing: Oxides of the metal molybdenum are formed and used for formation by means of an electrochemical process typical microstructure with the sliding surface as a basis on this is bound. 2) tribological workpiece according to claim 1, characterized in that that the matching layer (1), which is anchored with the base metal, in a thickness between 0.5 µm and 3 µm, preferably 1 µm. • · t r · ■ * * * ti ι i »a« · »< Dipl.-Phys. Heinrich Seids · Patent attorney ■ Bierstadter Höhe 15 · PO Box 5105. 6200 Wiesbaden 1 - ® (0 6121) 56 7.0 3) tribological workpiece according to claim 1 or 2, characterized in that the structure of the Adaptation layer (1) is a structure formed by cathodic electrolysis. 4) tribological workpiece according to one of claims 1 to 3, characterized in that a? Base layer (4) made of a nickel-tin alloy with a tin content between about 30 and 90 wt .-% and with a thickness of a maximum of 0.1 mm, preferably 0.005 mm to 0.015 mm, thick sliding layer (2) made of bearing material from a Brinell hardness between about 4 and 30 is covered and over this sliding layer (2) a uniform, micro-cracked (mosaic-like) adaptation layer (1) made of oxides of the metal molybdenum anoe- I ^ is arranged. 5) Tribological workpiece according to one of claims 1 to 4 in the form of a slide bearing element, thereby ge | indicates that the sliding layer (2) of the sliding bearing element carrying the adaptation layer (1) is formed from a bearing alloy with ± 0 to 2½% tin, 6 to 10% copper, the remainder lead, in particular 16% tin, 8% copper, the remainder lead . • II ·· t · t »· ■ III t · · ··· « I tlllt · «· · ·· · · t I Il I It · · Dipl.-Phys. Heinrich Seids · Patent Attorney · Blerstadter Höhe 15 · P.O. Box 5105 · 6200 Wiesbaden 1 · ® (06121) 56 20 - 3 - 6) tribological workpiece according to claim 5 in the form of a sliding bearing element, characterized in that the sliding layer carrying the adaptation layer (1) (2) of the plain bearing element by a suspension alloy that tends to separate, in particular an aluminum-lead alloy that tends to segregate is formed.