JPS6143421B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses aluminum Al as a base material. This relates to aluminum-tin (Sn) bearing materials. In more detail, we improved the low melting point material contained in the Al-Sn bearing alloy and dispersed a large amount of hard substances in the alloy, resulting in excellent wear resistance.
Our objective is to provide Al-Sn bearing alloys. Al-Sn alloys are mainly used as conventional aluminum bearing alloys, but when modern automobile internal combustion engines are used under higher speed and higher load conditions, this alloy becomes more difficult to maintain between the shaft and the bearings. The lubricating oil film present in the bearing becomes thinner, making direct contact between the shaft and the bearing more likely to occur, resulting in increased bearing wear or seizure. Therefore, the object of the present invention is to provide an Al--Sn bearing alloy that has sufficient wear resistance even when the shaft and bearing come into direct contact, and also has excellent load carrying capacity. That is, Sn3 to 40 with Al as the substantial remainder.
%, lead (Pb) 0.1-5.0%, antimony (Sb) 0.1
Silicon (Si), nickel (Ni), manganese (Mn), iron (Fe), zirconium (Zr), molybdenum (Mo), less than ~3% and for hard material generation.
A bearing alloy containing one or more of vanadium (V), cobalt (Co), and niobium (Nb) in a total amount of more than 3.0% and less than 10.0%, and the hard material precipitated in the base material is rolled. bearing alloy (alloy 1) dispersed in its base material. Alloy 1 with 0.1-3.0% Cu and/or Mg
The present invention provides a bearing alloy (alloy 2) containing the following: Next, the characteristics of the various elements added to the alloy are as follows: Sn: This is an element added primarily for the purpose of lubrication. The finer the Sn is dispersed in Al, the more it ensures lubricity and maintains overall mechanical strength. If it is less than 3%, there will be no lubrication effect, and if it is more than 40%, the whole will become soft and lose its load bearing capacity. Pb: An element added primarily for lubrication, but it is a material with better lubricity than Sn. Furthermore, when it is present together with Sn, it forms a partial Sb--Pb alloy element, and when an element with a lower melting point than Sn and Pb is present, a lubricity effect is particularly exhibited when metal contact occurs. If it is less than 0.1%, there is no lubrication effect, and if it exceeds 5.0%, dispersibility decreases and castability deteriorates. Sb: Has the effect of dispersing Pb relatively finely, and when present together with Sn and Pb, Sn-Pb-
Create an alloy of Sb to create a soft metal with a high melting point and hardness. This improves the load carrying capacity and high temperature properties of the soft material. Also extra Sb
produces precipitates such as Al-Sb and Al-Sb-Si, and since these precipitates are very hard, proper dispersion of these precipitates leads to improved load carrying capacity and wear resistance. In this sense, adding 0.1% or more satisfies the above requirements, and adding 3.0% or more results in too much precipitate. Cu/Mg: Strengthens the Al base to improve load resistance and fatigue strength, preventing a decrease in hardness when the bearing is exposed to high temperatures (over 200℃). No effect below 0.1%
If it exceeds 3.0%, the Al base will become too hard. Si, Ni, Mn, Fe, Zr, Mo, Co, V, Np: These elements (generally added in the master alloy)
By casting with Al, crystallized substances and precipitates are generated, and by further rolling, the precipitates, that is, hard substances, are dispersed in the base material. All of these hard substances have a Bitkers hardness of several hundred or more, which improves the hardness and wear resistance of the entire alloy. If the amount of these elements added is less than 30%, the amount of hard substances precipitated will be small and the effect will not be expected, and if it is more than 10%, too many hard substances will precipitate, resulting in poor rolling properties and problems caused by rolling. The dispersibility of hard materials also deteriorates. Note that an element alloyed with each other or an element alloyed with Al may be added. Here, the preferred range is Sn: 6-20% Pb: 0.5-4.0% Sb: 0.5-2.0% Cu/Mg: 0.2-2.0% Si, etc.: 3.0-6.0% Next, the present invention will be explained with examples. . The following table shows alloys 1 to 8 according to the present invention, and alloys 9 to 11 for comparison.
It shows the chemical composition value of.

【table】

[Table] For Alloys 1 to 8, Al base metal is melted in a gas furnace, and then Al-Sb mother alloy, Al-Cu mother alloy, Al-
Mg master alloy, Al-Si master alloy, Al-Mn master alloy, Al-
Ni master alloy, Al-Fe master alloy, Al-Zr master alloy, Al-
Co master alloy etc. are melted according to the target components and finally Sn
After adding Pb and degassing, the product was cast into a mold and then rolled and annealed (350
℃) was repeated to prepare samples, and the hardness was measured. At this time, the precipitates precipitated in the base metal are sufficiently dispersed in the base metal by the above-mentioned rolling, thereby improving the mechanical properties of the entire alloy. That is, in a cast material having a composition within the range of the present invention, segregation occurs and the material becomes brittle. Figure 4 a shows Si
50% and other compositions within the range of the present invention, and Figure 5 a schematically shows the segregation state of Al-Mn alloy when Mn is 4.5%. It is shown as a diagram. Furthermore, FIGS. 4b and 5b show a state in the present invention in which the cast material of FIGS. 4a and 5a is rolled and the precipitated hard material is dispersed in the base material. In cast materials where hard materials exist in a segregated state,
Cracks and creases tend to occur in the segregated portions, resulting in poor mechanical properties such as brittleness, and generally, if the amount of the above-mentioned elements added exceeds 3%, it becomes unusable. In contrast, in the present invention, by adding more than 3% of the above elements, many hard substances are actively precipitated, and this is further rolled to disperse the segregated hard substances in the base material. (see Figures 4b and 5b), thereby improving mechanical properties such as brittleness and making it possible to put it into practical use. Next, for the samples whose hardness was measured above, these alloys were bonded to a backing steel plate to form a bimetallic material, which was annealed and then processed into a flat bearing and subjected to a friction test. This test result is
This corresponds to the results of a friction test conducted by directly processing the alloy into a flat bearing. For Alloys 9 to 11, comparative alloys were prepared using the same manufacturing method as the above-mentioned alloys, and the same tests were conducted using them as samples. FIG. 1 shows the results of measuring the hardness of Alloys 1 to 8 by Witzker's hardness. As is clear from these graphs, Alloys Nos. 1 to 8 according to the present invention have the same or higher hardness than Comparative Alloys Nos. 9 to 11. This is due to the hardness of the precipitates. Furthermore, as is clear from FIG. 2, in which the hardness of alloys to which Cu and/or Mg have been added is measured at elevated temperatures, there is little decrease in hardness even at high temperatures. This means that the bearing has load resistance and wear resistance even when used at high temperatures. Next, FIG. 3 shows the results of a friction test conducted on alloys 2, 4, and 7 according to the present invention and comparative alloys 9, 10, and 11. In this experiment, the shaft rotation speed was 1000 rpm, S55C hardened material was used as the shaft material, the shaft surface roughness was 1 μm, and the wear was measured when the load was increased under forced lubrication at a constant oil temperature (120°C). It is a graph showing the results of measuring the state of change in amount. According to this graph, compared to alloys 9, 10, and 11, which were comparative materials, alloys 2, 4, and 7 were found to have extremely small amounts of wear, indicating excellent wear resistance. This is recognized to be the effect of hard materials dispersed in the Al ground. It goes without saying that in the alloy composition according to the present invention, Al contains impurities that cannot be avoided by ordinary refining techniques. As mentioned above, the Al-Sn bearing alloy according to the present invention has a large amount of hard material dispersed in the base material by rolling, so it is less brittle than an alloy in which a large amount of hard material is segregated. It is possible to improve the mechanical properties such as, etc., and to make it possible to put it into practical use. Furthermore, adding Cu and/or Mg further improves high temperature strength.

[Brief explanation of the drawing]

FIG. 1 is a graph plotting the hardness of the Al--Sn bearing alloy according to the present invention and a comparative bearing alloy of the same type. Figure 2 is a graph plotting changes in hardness due to temperature changes. Figure 3 is a graph showing changes in the amount of wear when the load is similarly increased on the steel shaft. Figure 4a shows the segregation state of Si when Si is 5.0% and other compositions are within the range of the present invention, and Figure 4b shows the hard material segregated by rolling the same figure a into the base material. A schematic diagram showing a dispersed state. Figures 5a and 5b are schematic diagrams corresponding to Figure 4a and b when Mn is 4.5%, respectively.

Claims (1)

[Claims] 1 3 to 40% tin, 0.1 to 5% lead, 0.1 to less than 3% antimony, silicon, nickel, manganese, iron, zirconium, molybdenum, cobalt,
An aluminum bearing alloy containing one or more of vanadium and niobium in a total of more than 3.0% and less than 10.0%, and the balance being substantially aluminum, and the hard material precipitated in the base material is removed by rolling. An aluminum bearing alloy characterized by being dispersed in the base material. 2. Tin 3-40%, lead 0.1-5%, antimony 0.1-3%, copper and/or magnesium 0.1-3%, silicon, nickel, manganese, iron, zirconium, molybdenum, cobalt,
An aluminum bearing alloy containing one or more of vanadium and niobium in a total of more than 3.0% and less than 10.0%, and the balance being substantially aluminum, and the hard material precipitated in the base material is removed by rolling. An aluminum bearing alloy characterized by being dispersed in the base material.