DE3000772A1 - Aluminium-tin bearing alloy - contg. chromium and hardening additives to improve softening and seizing resistance - Google Patents

Abstract

An Al-Sn base bearing alloy has the compsn. (by wt.) 3-7% Sn, 0.1-1.0% Cr, 1-10% total of one or more of Si, Mn, Sb, Ti, Zr, Ni, Fe, W, Ce, Nb, V, Mo, Ba, Ca and Co, 0.1-less than 0.8% total of Cu and/or Mg, balance Al. The alloy may also contain up to 9% total of one or more of Pb, Bi, Tl, Cd and In. The alloy is pref. applied to a backing steel sheet by pressure welding and used as a bearing in contact with a shaft of spheroidal graphite cast iron. The alloy is useful for i.c. engine bearings which contact crankshafts of spheroidal graphite cast iron. The bearings have improved hardness, resistance to softening at high temp., fatigue strength, wear resistance and antiseizing properties.

Description

Al-Sn bearing alloy, bearing plant made from it

fabric and shaft bearing provided therewith The invention relates on an aluminum-tin (Al-Sn) based bearing alloy made by Tin is added to an aluminum matrix and a bearing material that is manufactured is made by pressure welding the Al-Sn-based bearing alloy onto a steel base is applied. In particular, the bearing alloy is based on Al-Sn according to the Invention characterized in that the bearing alloy with regard to several properties is improved by using various types of additional elements. That means the fatigue strength is greatly improved by reducing the hardness at high temperatures and in particular by the coarsening of the tin particles is avoided. In addition, the wear resistance of the bearing alloy is increased, to improve the durability compared to a shaft to be stored, which is a hard one and has a rough surface. In the case where the bearing alloy according to the invention for bearing devices on crankshafts used by internal combustion engines which require severe conditions can accordingly expect considerable advantages will.

In recent years, it has become necessary to use automotive internal combustion engines compact and with high performance. They also need to be used as a countermeasure to the exhaust gas regulations with return devices and the like. Provided that Return unburned mixture (blown gas) that has passed into the crankcase.

The conditions of use for the bearing materials in internal combustion engines have therefore become harder under high loads and high temperatures. Under Conventional bearing materials tend to fail in such harsh conditions due to fatigue and abnormal wear and tear, due to the various malfunctions of the Motors are caused.

In connection with the shafts that come into contact with the bearing materials are brought, there is a tendency that the forged shafts manufactured so far be replaced by less expensive shafts made of ductile iron or other rough material, to reduce manufacturing costs. The improvement in wear resistance, in resistance to seizure and in fatigue strength at high temperatures is therefore all the more necessary.

Examples of the Al-Sn-based alloy used for manufacturing the Bearings used by internal combustion engines in the state of the art are: Al (remainder) - Sn (3.5-4.5) - Si (3.5-4.5) - Cu (0.7-1.3); Al (balance) - Sn (4-8) - Si (1 - 2) - Cu (0.1 - 2) - Ni (0.1 - Al (remainder) - Sn (3 - 40) - Pb (0.1 - 5) - Cu (0.2 - 2) -Sb (0.1-3) - Si (0.2-3) - Ti (0.01-1); Al - (balance) -Sn (15-30) - Cu (0.5-2); and Al (remainder) - Sn (1 - 23) -Pb (1.5 - 9) - Cu (0.3 - 3) Si (1 - 8), where the values in brackets are the percentages by weight of the material components indicate.

If these conventional alloys for the bearings of automotive internal combustion engines are used under severe conditions as described above, Sometimes the engines fail in a short period of time due to fatigue are constantly operated under heavy loads. This is due to the fact that the temperature of the lubricating oil in an internal combustion engine during the continuous Full load operation is very high, and for example, the temperature of the lubricating oil Reach 130 OC to 150 OC in a blwanne, so that the temperature of the sliding surfaces is also increased very sharply by bearings.

As a result, there becomes the eutectic point of such an alloy is of the order of 225 OC, the hardness of the alloy under the high temperature conditions quickly low, causing the Sn component to melt and migrate, and has the consequence that the fatigue strength is reduced. The inventors of the present Invention have made an alloy whose hardness at high temperatures is not is decreased and in which the Sn component is hardly movable. From the alloy were made by machining bearings for internal combustion engines and these were made Exposed to long-term tests under dynamic loads at high oil temperatures. The improvement of the fatigue strength could be made through the considerations above have been established.

In addition to lowering fatigue strength due to loss Hardness at high temperatures, as mentioned above, causes coarsening of Tin particles in the structure of conventional Al-Sn alloy also sink the fatigue strength. This means that the aluminum bearing material is generally manufactured by applying an Al-Sn alloy to a steel substrate by pressure welding an annealing step after pressure welding is required to maintain the adhesive strength to improve between the two metals.

The annealing is generally carried out at a temperature below Point at which an Al-Fe intermetallic compound is deposited, and the higher the treatment temperature and the longer the treatment time so bigger becomes the adhesive strength. In fact, if the conventional Al-Sn alloy during annealing to a high temperature state is brought, the coarsening of the aluminum grain boundaries and tin particles disadvantageously caused in the alloy structure. That is, if the conventional aluminum bearing alloy is subjected to an annealing process in order to increase the adhesive strength on the steel substrate improve, it comes to coarsening of the tin particles, which reduces the fatigue strength the Al-Sn alloy at high temperatures.

Further, these conventional Al-Sn bearing alloys are in terms of their wear resistance is not good enough. Especially when waves are tough and rough surfaces, for example those made of nodular cast iron, with the bearing alloys are brought into contact, the wear resistance is greatly reduced and failure due to fatigue occurs, which is a serious one in the prior art Problem.

To eliminate or reduce the disadvantages of the The invention accordingly creates a conventional bearing alloy based on Al-Sn Al-Sn-based bearing alloy with a relatively low loss Hardness comes at high temperatures and which accordingly has a high fatigue strength.

The invention also creates an improved bearing alloy Al-Sn base, in which there is no or only moderate coarsening of the tin particles during of the glow step or during use under high temperature conditions, which results in a higher fatigue strength.

The invention also provides a bearing alloy based on Al-Sn with a relatively high wear resistance, especially with respect to waves hard and rough materials such as ductile iron, which is used to manufacture crankshafts used by internal combustion engines.

Finally, the invention provides a bearing material that is manufactured is done by placing the bearing alloy described above on the surface of a sheet steel pad is applied, as well as bearings for internal combustion engines resulting from the above Bearing material are made.

According to the invention, the Al-Sn-based bearing alloy basically contains 3 to 7 wt% Sn; 0.1 to 1.0 wt% Cr; 1 to 10% by weight in total of one or several of the specified additives Si, Mn, Sb, Ti, Zr, Ni, Fe, W, Ce, Nb, V, Mo, Ba, Ca and Co; 0.1 to below Ot8% by weight Cu and / or Mg; Remainder aluminum. The alloy can further 9% by weight in total of one or more of the elements Pb, Bi, Tl, Cd and In contained, thereby improving the storage properties.

Several embodiments of the invention are discussed below Described in more detail with reference to the accompanying drawings. 1 shows a Diagram showing the changes in wear loss of alloys with the increase of Shows loads that are exerted on steel shafts, which with the alloys are in contact, and Fig. 2 is a graph showing the wear loss changes of alloys shows the increase in loads acting on nodular cast iron shafts which are in contact with the alloys.

The Al-Sn-based bearing alloy according to the invention is produced by adding the above-mentioned Cr, one or more of the specified additives and Cu and / or Mg can be added to the aluminum matrix.

In connection with the amount of tin, the conformability and the lubricating properties can be improved overall with an increasing amount of tin, but the hardness is reduced will. The load capacity of a bearing is therefore low. If, on the other hand, the amount of tin becomes low, the load capacity is increased, but the alloy is used as a bearing material too hard and the fit becomes worse. In the prior art, the upper one Limit for the tin content in general about 15% and the lower limit about 38. In the invention, the tin content is limited to the range of 3 to 7%, in to whom the resilience is good.

The addition of chromium (Cr) causes the hardness of the alloy to increase and the alloy is prevented from softening at high temperatures, so that the coarsening of the tin particles does not occur even during annealing. Be first the effects of increasing hardness and avoiding softening the Alloy described at high temperatures. When the amount of chromium is less than 0.1 wt%, the improvement in hardness at high temperature cannot be expected will. If the amount of chromium added exceeds 1.0% by weight, the intermetallic Al-Cr compound cannot be dispersed finely and evenly, which will be discussed below is described in more detail, which is why the effect of the addition is small. Accordingly the amount of chromium added is limited to the range from 0.1 to 1.0% by weight. In particular In connection with the improvement of the hardness at high temperature forms the chromium a solid solution in the aluminum that is the recrystallization temperature of the aluminum and moreover, the solid solution itself improves the hardness of the aluminum matrix. At the same time, the hardness of the alloy containing chromium becomes higher even if it is rolled several times, which is a contrast to casting. With the increase the recrystallization temperature of aluminum can make the engine bearings that high Exposed to temperatures, their mechanical properties are retained. In particular the lowering of the hardness at high temperatures and the softening can be reduced of storage in a high temperature area can be avoided well, thereby reducing the The durability of the bearings is improved. Furthermore, the intermetallic Al-Cr compound, which is precipitated above the limit of the solid solution has a Vickers hardness of more than 370, so the dispersion of this compound helps the bearing alloy maintain hardness at high temperature. The dispersion of such intermetallic compound in the right amount therefore has a beneficial effect. As described above, the preferred range of the amount of chromium is 1.0% by weight or less, and if the amount of chromium is within this range, it results a fine and even deposition of the intermetallic compound and the The hardness of the bearing alloy is increased.

The following is the effect of adding chromium to avoidance the coarsening of the tin particles. The coarsening of the tin particles is a phenomenon related to the migration of aluminum grain boundaries and tin particles is due to the Al-Sn alloy at a high temperature. There the Chromium is precipitated as the above-mentioned Al-Cr intermetallic compound, which is finely distributed in the aluminum alloy matrix, blocks this intermetallic Link directly the wandering of the aluminum grain boundaries and at the same time hinders the growth of aluminum crystal grains. The migration of tin particles will therefore also hindered and, as a result, the coarsening of the tin particles can be avoided will. This is related to the fact that the finely divided tin particles held where they are during the repetition of rolling and annealing so that the above-mentioned various effects can be obtained.

Further can the liquefaction of tin particles, which have a low Melting point of about 232 OC, effectively prevented under high temperature conditions because the tin particles are in a finely distributed state in the aluminum matrix being held. From this point of view, the effect of preventing the lowering of the hardness understandable.

The above is the effect of preventing the coarsening of the Tin particles described in the annealing step.

This effect can also occur in the processing state of the bearing material can be expected in which the temperature is equal to that in the annealing state. Accordingly, can the fatigue strength in practical use also with blocking the softening be improved.

In order to improve wear resistance mainly, one or more of the specified additives silicon (Si), manganese (min), antimony (Sb), Titanium (Ti), zirconium (Zr), nickel (Ni), iron (Fe), tungsten (W), cesium (Ce), niobium (Nb), vanadium (V), molybdenum (Mo), barium (Ba), calcium (Ca) and cobalt (Co) added. The additional amount of each of these elements is within the range of a line to 10% by weight, while the total amount of these elements is not more than 10% by weight and is preferably in the range from 1 to 6% by weight, this amount according to the intended use can be determined. The reason for the above limitation is the following. The excreted substances (or crystallized substances, the same shall apply in the following) these elements are dispersed in the aluminum matrix, therefore, the wear resistance can be improved. If the additional amount of the specified additive is less than 1 wt.%, the effect of the additive does not result, while if the addition amount is more than 10 wt.%, too much substance is eliminated, so that the adaptability to rolling becomes poor and that Repeating rolling and annealing becomes difficult. Next is the formation of the fine Tin particles blocked. To completely eliminate these unwanted effects, the preferred upper limit has been set at 6 wt% or so.

The forms of excretion of these specified additives are the excreted Substances of each added element that form the intermetallic compounds between the added elements, those of the intermetallic compounds of aluminum and added elements and those of the intermetallic compounds of aluminum and the intermetallic compound of added elements. The wear resistance can be improved by the excreted substances in all forms of the above will.

Reach the Vickers hardness of these excreted substances several hundred, so that the excreted substances are very hard and wear and tear of bearings caused by the friction with shafts, by the eliminated Substances can be reduced considerably. Accordingly, it can be a pretty good one Result can be achieved when a correct amount of the excreted substance is in the aluminum matrix is present. The correct amount range is as above described, from 1 to 10% by weight, and if the amount of excreted substance In-this range, the excreted substance can be dispersed evenly and the wear resistance can be effectively improved without being disadvantageous Effects such as lowering the ability to fit can be caused.

The effect of improving the wear resistance is considerable, when the bearing carries a shaft that has a hard and rough surface. The efficiency of the bearing generally depends on the hardness and roughness of the material to be supported Material to a large extent. If, for example, the conventional bearing material on Al-Sn base is used to support a shaft made of nodular cast iron, the Properties of the bearing in terms of preventing seizure and in terms of Wear resistance noticeably deteriorated. Because the ductile iron shafts are cheap can be made, they are more recently forged instead of the Steel shafts used extensively. There are soft graphite particles in the iron matrix of the shaft scattered. Therefore, when the shaft surface is scraped off, they become sheet-like Abrasive burrs are formed around the graphite particles. When the shaft showing such grinding burrs has, relative to the camp is shifted under heavy load, in which the Roughness of the shaft and the bearing and the thickness of the blfilms between them each other are the same, the bearing surface, which is softer than the shaft, is ground off. If this condition persists, the surface of the bearing becomes rough and the gap becomes between the bearing and the shaft becomes large, causing breakage or loss of the film leads. As a result, there is direct contact between the Shaft and bearing (i.e. to a metal-to-metal contact), the leads to eating of both parts.

In the alloy according to the invention, however, is the precipitated Substance found in the aluminum matrix through the addition of one or more elements the above-specified additives is formed harder than the above-mentioned grinding burrs the shaft made of ductile iron. The excreted substance therefore eliminates the above mentioned grinding burrs from the surface of the shaft and also is eliminated from the Substance transfer and adhesion of metal is hardly possible. The wear process the bearing surface can therefore be stopped within a relatively short time to cause the formation of a stable oil film. As a result, in With respect to the nodular cast iron shaft, the wear resistance and the property of the Preventing the bearing from seizing can be improved.

In the group of specified additives, the most desirable additive is Si, which Mn and Sb, then Zr, Mo, Fe and Co, then Ni, Ti and Ce and then Nb, W and V and finally Ba and Ca follow. It depends on the fact that the The hardness and castability of Si are excellent, so that Si is most preferable is used. The order of the other elements results from the Degree of uniform dispersion of the intermetallic compounds-with aluminum or other elements and easy castability. Mo and Co are re the corrosion resistance a little inferior, so that when particularly corrosion resistance Required in use, it is necessary to add the amount of these elements to reduce and use other elements.

In addition to the compositions of the invention described above the bearing alloy can further 0.1 to less than 0.8 wt.% Total copper (Cu) and / or Contains magnesium (Mg). Copper and / or Magnesium are given added that they reduce the drop in hardness at high temperatures. if the addition amount of them is less than 0.1% by weight cannot be so strong with any Increase in hardness can be expected. When the amount of Sn falls to the above narrow range of 3 to 7%, and the amount of Cu and / or Mg large is made, the alloy becomes too hard and leads to wear and tear of the one with it in Material in contact. The amount of Cu and / or Mg is therefore desirable less than 0.8 wt.%.

The effect of the addition of copper and / or can also be seen Magnesium, when chromium is added at the same time, and the effect of increasing the Hardness at high temperatures is not expected if only copper and / or magnesium can be added. If copper and / or magnesium are added to the aluminum matrix, so the hardness in rolling is greatly increased compared to the case in which other elements are added to the aluminum matrix, is noteworthy. It is however, it should be noted that the aluminum matrix containing copper and / or magnesium can be easily softened at around 200 OC, which is why it cannot be expected that the hardness is maintained at high temperatures. If on the other hand copper and / or magnesium are added together with chromium, the hardness, during rolling due to the effect of the addition of copper and / or Magnesium is increased, by the glow not so much decreased, which is the addition of the Chromium brings with it. This hardness can be maintained under high temperature conditions be, which is why the bearing alloy according to the invention compared to the known Alloys has a higher hardness at high temperatures, which improves the Fatigue strength results.

Furthermore, in the case of the bearing alloy according to the invention, the property being a tin-containing sliding metal, can be further improved by overall more than zero to 9% by weight of one or more of the elements lead (Pb), bismuth (Bi), thallium (Tl), cadmium <Cd) and indium (In) are added to the effect the addition of lead, bismuth, indium, thallium, and cadmium is shown when they can be added along with chromium. In the prior art it has been envisaged that to add these elements to Al-Sn-based alloys, and the addition is in some Cases have been applied. However, if only these elements of the Al-Sn-based alloy are added, they form alloys, which have the disadvantage that the melting point of tin becomes low cannot be avoided. Thus it comes with the known Al-Sn based alloy likely to melt and migrate the tin at low temperatures, causing the growth of tin particles to become larger and larger coarser particles is caused. If such an alloy as a bearing material is used, it comes to a partial operation under constant heavy load Melting and scraping. According to the invention, however, the tin particles are through The addition of chromium is made fine and the microstructure is at high temperatures retained in the bearing alloy according to the invention.

Even if one or more of the above elements are lead, bismuth, Indium, thallium and cadmium are added to the alloy, the lubricating property can of tin can be improved without the disadvantages of the prior art occurring. Furthermore, the bearing alloy according to the invention can be used for a bearing, which must have a high fatigue strength, and it is also possible that To improve the fit of the bearing material.

The additional amount of one or more of the elements lead, bismuth, Indium, thallium and cadmium, which have the above effects, are as above in the range of greater than zero to 9 wt% total. Under these Elements are most preferable to lead and indium, and these are followed by Bismuth and cadmium and then thallium. That depends on the fact that Lead and indium are most flowable under pressure, so that the sliding properties and the fit becomes good. The next elements, bismuth and cadmium, are Slightly harder compared to lead and indium and have higher melting points. That last element, thallium, has properties similar to lead and indium, the production quantity however, thallium is low and it is an expensive element.

One or more of the elements lead, bismuth, indium, thallium and Cadmium can be added along with the above-mentioned copper and / or magnesium thereby reducing the drop in high temperature hardness and at the same time the lubricating properties of the tin can be improved.

The above-described Al-Sn-based bearing alloy is mainly used Used for sliding bearings in automotive internal combustion engines and the like, the bearing alloy generally applied to and onto sheet steel substrates by pressure welding is then annealed to increase the adhesive strength.

In the case of the known Al-Sn-based alloys, however, it comes to Decrease in hardness, to melt the tin particles, etc. because of the aluminum grain boundaries and the tin particles migrate in the alloy structure, which coarsen the tin particles has the consequence. In the invention, the migration of the aluminum grain boundaries and effectively avoided the growth of aluminum crystal particles by the precipitated substance of the intermetallic Al-Cr compound, which in the pressure welding and annealing steps is generated. The bearing alloy according to the invention is therefore free from the above adverse influences of the glow and, as a result, the Adhesion strength between the Al-Sn-based alloy and the sheet steel supports can be made high by increasing the annealing temperature. Given the above fact on the case in which the bearing alloy according to the invention can be applied put in circumstances commensurate with the temperature of the glow, it is quite meaning that the fatigue strength improves by preventing softening can be. The improvement in wear resistance is also observed and the bearing alloy is particularly effective when used in conjunction with shafts made of nodular cast iron is used.

In the following the invention is illustrated in more detail by means of several examples described.

The following Table A shows the compositions of alloys (Samples) 1 1 to 17 according to the invention and of comparative alloys (samples) 18 until 22.

In the manufacture of alloys 1 to 17, an aluminum material was used melted in a gas furnace and according to the formulas of Table A, alloys became based on Al-Cu, Al-Mg and Al with specified additives in the molten Dissolved aluminum. Subsequently, Sn and Pb, Bi, Int Tl and Cd were added and degassing was performed. Then the metal was poured into molds and then repeatedly rolled and annealed (350 OC) to produce samples. The high temperature hardness of the samples was then measured. In the next step these samples were rolled and then the alloy samples were applied Steel sheet shims attached by pressure welding to make bimetallic samples. These were then annealed and processed into flat bearings and their fatigue strength under dynamic loads was tested. In the same way as above were alloys 18 through 22 were made for comparative tests and the same tests subject.

Table B shows the results of measuring the Vickers hardness of several alloys at an ordinary temperature and at 200 oC, the results of fatigue strength tests under dynamic loads and the results of seizure tests with steel shafts and nodular cast iron shafts. The above fatigue strength tests were carried out by repeating each alloy 107 times under the following conditions has been stressed and the strength of the stresses causing fatigue, was measured, i.e. the pressure at the fatigue limit by this number of repetitions.

Test machine: Soda Dynamic Load Tester sliding speed: 400 - 470 m / min Lubricating oil: SAE 10W30 Lubrication: Pressure lubrication oil temperature: 140 + 5 OC Oil pressure: 0.5 MPa Material in contact: Type: S 55 C Roughness: 1 pm Hardness: HV 500 - 600 bearing shape: diam. x width: 52 x 20 mm semi-divided metal roughness: 1 - 3 fm In the above eating tests, the stresses during eating were at loads increasing by 5 MPa (50 Kg / cm²) every 20 minutes under the following conditions measured. The following material (1) in contact with the bearing was made as a steel shaft and the material (2) in contact with the bearing was used as a ductile iron shaft.

Test machine: ultra high pressure seizure tester sliding speed: 468 m / min load: 5 MPa, gradually increasing every 20 min Lubricating oil: SAE 10W30 Lubrication: Pressure lubrication Oil temperature: 140 + 5 ° C Material (1) in contact: Type: S 50 C Roughness: 0.3 - 0.8 pm hardness: HV 500 - 600 material (2) in contact type: ductile iron (DCI) roughness: 0.3 - 0.8 pin hardness: HV 200 - 300 bearing shape: diam. x Width: 52 x 20 mm half-divided Metal roughness: 1 - 3 pin From table B it can be seen that the alloys 1 - 17 according to the invention in comparison to the comparison alloys 18 - 22 have a greater hardness in the high temperature range.

Especially in view of the fact that the comparative alloy has an ordinary temperature hardness higher than that of some alloys according to the invention, it is clear that the extent of the decrease in hardness is in the high temperature range is relatively low in the alloys according to the invention.

Furthermore, in comparison with the comparison alloys 18-22, the Alloys 1-17 according to the invention have relatively good results in terms of fatigue strength. The alloys were also found in seizure tests using nodular cast iron shafts excellent results according to the invention.

T able A Alloy. Example - alloy components (wt.%) No.Al Sn Cu Mg Pb Di In Ti Cd Cr Si Mn Sb Ti Ni Fe Zr W Ce Nb V Mo Sc Ca Co 1 Re 3.0 0.2 1.5 0.3 3.0 2 "6.0 0.5 2.0 0.4 2.5 3 "6.5 0.2 0.2 0.2 3.0 4 "6.0 0.2 1.0 1.0 7.0 0.5 2.0 5 "6.0 0.5 2.0 1.0 2.0 6 "4.5 0.5 1.5 0.3 2.5 7 "4.0 0.7 0.1 2.0 2.0 8 "6.0 0.2 1.5 0.5 2.0 9 "6.5 0.2 1.5 0.8 2.0 10 "4.5 0.1 1.5 0.3 0.5 11 "4.5 0.2 1.5 0.4 6.0 12 "4.5 0.2 0.4 2.0 13 "6.0 0.3 3.0 0.3 5.0 4.0 14 "6.0 0.3 3.0 0.3 2.0 15 "6.0 0.5 4.5 0.5 2.0 1.0 16 "6.0 0.5 3.0 3.0 0.2 0.4 5.5 17 "4.5 0.2 0.5 0.4 1.2 18 "6.0 1.0 1.5 0.5 19 "4.0 1.0 4.0 20 "4.5 1.0 1.5 2.5 21 "4.5 1.0 1.5 22 "6.0 1.0 Note: Re = remainder from Table B Alloy. Hardness (V} Endurance strength, stress, stress. Example - ordinary 200C speed (MPa) No. temperature 200C (MPa) steel- DC 1 wave 46 E; SIT 0 2 44- 2) 0 lGgO} 3 1 26. 6th 3 44: 120 Or 5 4 °>. 54 ° qO 65 3Q 6CFO 100 7th 40 i 25 W. 8 8 Q 29 0 90 0 9 4- g5 htT 10 10 43 Sq R? 0 0 k 30 8CL TZO 60. , 12 6-3680 3 13 X 25 80 QO 60 14 40 15 X? & 70 15 2 / c3n 2 CT3) Ocy 16 4 3e n oo 18 42 - - X q iX Ss: o 17 47 34 Q1; ~ r70 zo 2 52 22 30 21 560 22 22 35 17 t40 80 1 shows the results of friction tests in which the alloys 2, 3 and 17 according to the invention and the comparative alloys 21 and 22 were compared and steel shafts (material (1) in contact) were used. In Fig. 2 the results of other friction tests are shown, in which the alloys are the same as in Fig. 1 and nodular cast iron shafts (surface roughness: 1, to, hardness HV 200-300) were used under the same test conditions. 1 and 2 it can be seen that the wear losses of the alloys 2, 3 and 17 according to the invention compared to those of the comparison alloys 21 and 22 are quite low. Further, Figs. 1 and 2 show that the effect of improving wear resistance when ductile iron is used as the material in contact is quite clear as compared with the case of the steel shaft.

It should be noted that in the composition of the alloy according to the Invention the aluminum (Al) of course a trace amount of impurities that cannot be eliminated by ordinary refinement technique can.

Summary: The invention relates to a bearing alloy on aluminum-tin (Al-Sn) basis as well as on bearing materials, which by application the alloys are produced by pressure welding on a sheet steel base. The Al-Sn-based bearing alloy contains 3 to 7% by weight Sn; 0.1 to 1.0 wt% Cr; 1 to 10% by weight in total of one or more of the specified additives Si, Mn, Sb, Ti, Zr, Ni, Fe, W, Ce, Nb, V, Mo, Ba, Ca and Co; 0.1 to less than 0.8% by weight Cu and / or Mg; Remainder aluminum. The alloy can contain a total of 9% by weight contain one or more of the elements Pb, Bi, Tl, Cd and In, thereby increasing the storage properties be improved.

In an alloy according to the invention, the coarsening of Tin particles and the decrease in hardness under high temperature conditions are relative can be kept low, so that the wear resistance and fatigue strength the alloy can be improved. Bearing alloys according to the invention can be used for Internal combustion engine bearings are used in which generally crankshafts made of nodular cast iron can be used.

Claims (11)

P a t e n t a n s p r Ü c h e 2 Al-Sn bearing alloy, marked by essentially 3 to 7 wt.% Sn; 0.1 to 1.0 wt% Cr; 1 to 10% by weight in total of one or more of the specified additives Si, Mn, Sb, Ti, Zr, Ni, Fe, W, Ce, Nb, V, Mo, Ba, Ca and Co; not less than 0.1% by weight but less than 0.8 Wt% total Cu and / or Mg; Remainder Al. 2. Alloy according to claim 1, characterized in that Si as specified addition is selected. 3. Bearing material, characterized in that it is applied by applying of the alloy according to claim 1 or 2 on a steel sheet substrate by pressure welding is made. 4. Bearing alloy or bearing material according to one of claims 1 to 3, characterized in that the bearing alloy or the bearing material in a bearing in contact with a shaft made of nodular cast iron is used. 5. Al-Sn bearing alloy, characterized by essentially 3 to 7 wt% Sn; 0.1 to 1.0 wt% Cr; 1 to 10 wt% total of one or more the specified additives Si, Cr, Mn, Sb, Ti, Zr, Ni, Fe, W, Ce, Nb, V, Mo, Ba, Ca and Co; not less than 0.1 wt% but less than 0.8 wt% in total Cu and / or Mg; 9% by weight or less in total of one or more of the elements Pb, Bi, Tl, Cd and In; Remainder Al. 6. Bearing alloy according to claim 5, characterized in that Si is selected as the specified addition. 7. Bearing material, characterized in that it is applied by applying the bearing alloy according to claim 5 or 6 on a sheet steel base by pressure welding is made. 8. bearing alloy or bearing material according to any one of claims 5 to 7, characterized in that the bearing alloy or the bearing material in one Bearing in contact with a shaft made of ductile iron is used. 9. Bearing material, characterized by a bearing alloy according to a of claims 1 to 5. 10. Shaft bearing, characterized by a bearing alloy according to one of claims 1 to 5 and / or a bearing material according to claim 9. 11. Internal combustion engine, characterized by a shaft made of spheroidal cast iron, which is stored in several bearings according to claim 10.