阅读说明：本技术 适用于制作滑动轴承的铝合金材料 (Aluminum alloy material suitable for manufacturing sliding bearing ) 是由 张海涛 魏伟 郑强 于 2020-07-06 设计创作，主要内容包括：一种适合于制造滑动轴承的铝合金,本发明的铝合金的各成分的质量百分比为：Zn 3.0-8.0wt％,Si 3.5-7.5wt％,Cu 0.4-2.5wt％,Fe 0.3-2.5wt％,Zr 0.05-0.20wt％,P 0.01-0.05wt％,余量为Al、附带的元素和不可避免的杂质。微合金化附带元素为Hf、Nb、Ti、V、Sc、Er、Yb中的一种或多种,微合金化附带元素的添加总量满足0.06％≤(Zr+Hf+Nb+Ti+V+Sc+Er+Yb)wt％≤0.25％。铝硅合金中不可避免的杂质元素每种≤0.05wt％,总和≤0.15wt％。(The invention relates to an aluminum alloy suitable for manufacturing a sliding bearing, which comprises the following components in percentage by mass: 3.0 to 8.0 wt% of Zn, 3.5 to 7.5 wt% of Si, 0.4 to 2.5 wt% of Cu, 0.3 to 2.5 wt% of Fe, 0.05 to 0.20 wt% of Zr, 0.01 to 0.05 wt% of P, and the balance of Al, incidental elements and inevitable impurities. The microalloying incidental elements are one or more of Hf, Nb, Ti, V, Sc, Er and Yb, and the total addition amount of the microalloying incidental elements is more than or equal to 0.06 percent (Zr + Hf + Nb + Ti + V + Sc + Er + Yb) and more than or equal to 0.25 percent by weight. The inevitable impurity elements in the aluminum-silicon alloy are less than or equal to 0.05 wt% of each kind and less than or equal to 0.15 wt% of the total.)

1. The aluminum alloy material suitable for manufacturing the sliding bearing comprises the following basic components in percentage by weight: 3.0 to 8.0 wt% of Zn, 3.5 to 7.5 wt% of Si, 0.4 to 2.5 wt% of Cu, 0.3 to 2.5 wt% of Fe, 0.05 to 0.20 wt% of Zr, 0.01 to 0.05 wt% of P, and the balance of Al, incidental elements and inevitable impurities.

2. An aluminium alloy suitable for use in the manufacture of a sliding bearing according to claim 1, wherein: the aluminum alloy contains: 3.5 to 7.5 wt% of Zn, 3.8 to 7.5 wt% of Si, 0.5 to 2.2 wt% of Cu, 0.5 to 2.2 wt% of Fe, 0.05 to 0.20 wt% of Zr, 0.01 to 0.05 wt% of P, and the balance of Al, incidental elements and inevitable impurities.

3. An aluminium alloy suitable for use in the manufacture of a sliding bearing according to claim 2, wherein the aluminium alloy may further incorporate microalloyed incidental elements Hf, Nb, Ti, V, Er, Sc, Yb, whether further additions of a single incidental element or further additions of a combination of 2 or more incidental elements, the total amount of incidental elements being such that 0.06 ≦ (Zr + Hf + Nb + Ti + V + Er + Sc + Yb) wt% 0.25 wt%.

4. An aluminium alloy suitable for use in the manufacture of sliding bearings according to claim 2, wherein the inevitable impurity elements are 0.05 wt% or less each and 0.15 wt% or less in total when the aluminium alloy is smelted to produce the aluminium alloy.

Technical Field

The present invention relates to an aluminium alloy with a combination of soft phases and hard particles, which can be used for the manufacture of sliding bearings. The soft phase is elemental zinc and the hard particles comprise silicon and other intermetallic particles.

Background

The bearing bush is a vital part for any engine. The bearing bush must satisfy the load of engine under the different operating modes, for other spare parts provide the lubrication, reduce friction. As a key part, the bearing bush is easy to lose efficacy and damage, and the running state and the service life of the bearing bush influence the normal running of the whole engine.

The metal bearing bush alloys widely used at present have three main types: babbitt metal, copper-based alloy, aluminum-based alloy. The aluminum-based alloy has the comprehensive properties of good corrosion resistance, wear resistance, friction reduction, seizure resistance, compliance, embeddability and the like, has the advantages of small density, large bearing capacity, high fatigue strength, good heat conductivity and the like, is low in price and rich in resources, and is more and more applied to replace the traditional tin bronze and babbitt metal. At present, common aluminum-based bearing bush alloys include Al-Sn series, Al-Zn series, Al-Pb series and the like.

Because of the serious pollution problem of lead to the environment, the aluminum-lead bearing material is basically eliminated. The development trend of light weight, high power output and miniaturization of the engine puts forward higher requirements on wear resistance, high temperature resistance, bearing and environmental protection for the bearing bush material, and the aluminum-tin-based alloy bearing bush material cannot meet the requirements due to lower strength. The Al-Zn bearing alloy is a new Al-base bearing alloy material, which uses Al as base and Zn content is about 5%. The aluminum-zinc bearing alloy has high bearing capacity and is suitable for main bearings and connecting rod bearings of high-speed, heavy-load and supercharged reinforced diesel engines. The aluminum-zinc alloy has no pollution in the smelting process, saves electricity and tin, and has rich zinc resource and lower price in China. Therefore, the aluminum-zinc bearing alloy material has good development prospect.

German patent document DE19800433C2 discloses an aluminium alloy material for bearings, which contains 3-6 wt.% zinc, 0.3-2.0 wt.% copper, 0.2-1.0 wt.% magnesium, 0.3-2.0 wt.% silicon and 2-4.5 wt.% lead. Although the alloy has higher strength and good wear resistance, the trial use of the bearing alloy can cause pollution to the environment due to the fact that the alloy contains higher lead content, and the bearing alloy is not suitable for the requirement of green development of the current society.

Japanese patent document JPH036345A (US5028393) discloses an aluminum alloy for a sliding bearing having excellent fatigue resistance and seizure resistance, the basic composition of which is 1 to 10% wtZn, 1 to 15% wtSi, 0.1 to 5% wtCu, 0.1 to 5% wtPb, 0.005 to 0.5% wtSr; the base alloy may also be added with one or two of 0.05-5% wtMg, 0.05-5% wtNi, and one or more of 0.05-2% wtMn, 0.05-2% wtV, 0.05-2% wtCr. Although the aluminum alloy material has excellent fatigue resistance and seizure resistance, the alloy does not meet the concept of green development because it contains lead element which is harmful to the environment.

Similarly, the aluminum alloys disclosed in US4170469, US6328823B1 and US6783869 for sliding bearings also do not meet the concept of social development because they contain different contents of heavy metal lead elements which are harmful to the environment.

Chinese patent document CN86103116A discloses an aluminum-zinc-silicon-manganese-rare earth alloy for manufacturing a sliding bearing. The alloy comprises the following basic components: 20-40 wt% of Zn, 3-20 wt% of Si, 1-10 wt% of Cu, 2-12 wt% of Mn, 0.01-0.2 wt% of Mg, 0.02-1.0 wt% of Re and Al; in addition, 0.5-4.0 wt% of Sb, 0.1-2 wt% of Pb and 0.02-1.0 wt% of Ti can be added into the alloy; and the aluminum alloy and the bearing steel shell are cast into a whole by adopting a direct casting process. Although harmful lead element can not be added into the aluminum alloy, the high zinc content in the aluminum alloy not only causes the low strength of the alloy and is not beneficial to the fatigue performance of the bearing, but also reduces the stress corrosion resistance of the aluminum alloy due to the high zinc content.

Japanese patent document JPH05332364A discloses an aluminum alloy for a high-wear-resistance sliding bearing, the basic composition of which contains 2 to 8% wtZn, 0.1 to 8% wtSi, 0.1 to 3% wtCu and 0.05 to 3% wtMg; the aluminum alloy may further contain, on the basis of the basic components, one or more of 0.1 to 3% of Pb, 0.1 to 2% of Mn, 0.1 to 2% of V, 0.1 to 2% of Cr, 0.1 to 3% of Ni, and one or more of 0.005 to 0.5% of Sr, 0.01 to 0.2% of Ti, and 0.001 to 0.05% of B. Except for lead with pollution, elements such as Mn, V, Cr, Ni, Ti, B and the like are common alloying elements of the aluminum alloy, and the addition of the elements can form a large amount of hard particles in the aluminum alloy to improve the wear resistance of the aluminum alloy, but can also obviously improve the strength of the aluminum alloy and reduce the deformation performance of the aluminum alloy, and is not beneficial to the compliance of a sliding bearing.

The aluminum alloys disclosed in US5925315 and US20050191204a1 have higher strength and better fatigue strength, but have lower ductility and poor conformability.

Disclosure of Invention

The invention aims to provide an environment-friendly aluminum alloy material for manufacturing a sliding bearing, and the aluminum alloy has good wear-resisting and friction-reducing performance, good corrosion resistance and good plasticity and toughness so as to meet the use requirement of the sliding bearing.

In order to achieve the purpose, the invention adopts the technical scheme that:

an aluminum alloy suitable for manufacturing a sliding bearing comprises the following basic components in percentage by weight: 3.0 to 8.0 wt% of Zn, 3.5 to 7.5 wt% of Si, 0.4 to 2.5 wt% of Cu, 0.3 to 2.5 wt% of Fe, 0.05 to 0.2 wt% of Zr, 0.01 to 0.05 wt% of P, and the balance of Al, incidental elements and inevitable impurities.

The first preferred scheme of the invention is as follows:

the aluminum alloy mainly comprises: 3.5 to 7.5 wt% of Zn, 3.8 to 7.5 wt% of Si, 0.5 to 2.2 wt% of Cu, 0.5 to 2.2 wt% of Fe, 0.05 to 0.2 wt% of Zr, 0.01 to 0.05 wt% of P, and the balance of Al, incidental elements and inevitable impurities.

The second preferred scheme of the invention is as follows:

the aluminum alloy can also be further added with at least one of micro-alloying accessory elements Hf, Nb, Ti, V, Sc, Er and Yb, wherein the addition amount of at least one of the micro-alloying accessory elements Hf, Nb, Ti, V, Sc, Er and Yb is more than or equal to 0.06 (Zr + Hf + Nb + Ti + V + Sc + Er + Yb) wt% and less than or equal to 0.25 wt%.

The aluminum alloy suitable for manufacturing the sliding bearing and the preparation method thereof have the following advantages:

the main alloying elements Zn, Si, Cu, Fe, Zr and P and the micro-alloying elements Hf, Nb, Ti, V, Sc, Er and Yb of the aluminum alloy material are common elements of aluminum alloy, have wide sources and do not have bad effect on environmental protection.

The elements are added into the aluminum alloy, the comprehensive performance of the aluminum alloy is adjusted to meet the performance requirement of the sliding bearing on the aluminum alloy, and the design principle of the components of the aluminum alloy is explained in detail as follows:

the main function of zinc in the alloy of the invention is to provide a low-melting-point soft phase and simultaneously have a certain solid solution strengthening effect on the aluminum alloy. 2 wt% of zinc (Zn) can be dissolved in the Al matrix at room temperature to the maximum extent, and a proper amount (3.0-8.0 wt%) of zinc can form enough low-melting-point soft zinc particle phases in the aluminum alloy, so that the embedding property, the compliance and the seizure resistance of the bearing are guaranteed; compared with Al-Zn, the oxide film is also preferentially oxidized, so that the harmful effect of a hard Al oxide film can be eliminated; the addition of zinc increases the affinity of the aluminum alloy to lubricating oil and improves the lubricating performance of the bearing; if the amount of Zn added is less than 3 wt%, the above-mentioned intended effects cannot be obtained, and if the amount of Zn exceeds 8 wt%, the corrosion resistance of the aluminum alloy is lowered and stress corrosion cracking is liable to occur, and at the same time, the coating adhesion of the surface of the bearing alloy is lowered, which is disadvantageous for the coating of the antifriction layer on the bearing surface. In order to reasonably control the performance of the aluminum alloy, the preferable content of zinc (Zn) in the alloy is as follows: 3.5-7.5 wt%

In the aluminum alloy, silicon (Si) provides a hard particle phase, so that the aluminum alloy has good wear resistance, and the aluminum alloy of the bearing and the adaptive shaft are prevented from being occluded and bonded. If the addition amount of Si is less than 3.0 wt%, silicon particles in the aluminum alloy are small, and the wear resistance is insufficient, and if the amount of Si exceeds 7.5 wt%, the alloy has low ductility and toughness, and the impact fatigue strength is poor, which is not favorable for subsequent plastic processing such as rolling. The preferred silicon (Si) content of the alloy is: 3.8-7.5 wt%.

Copper (0.4-2.5 wt%) forms Al with Al₂The Cu nano-particle phase adjusts the strength of the aluminum alloy matrix, optimizes the fatigue resistance of the aluminum alloy, and simultaneously improves the corrosion resistance of the aluminum alloy by the solid-solution copper. The copper content is lower, such as less than or equal to 0.4 wt%, the strengthening effect of the copper and the effect of improving the corrosion resistance of the aluminum alloy are not obvious, and the content exceeds 2.5 wt%, the strength of the aluminum alloy matrix is higher, the fatigue performance is better, but the plasticity and toughness of the aluminum alloy are reduced, so that the compliance of the aluminum alloy is poorer. Therefore, the content of copper (Cu) in the alloy is preferably: 0.5-2.2 wt%.

In the alloy of the present invention, iron mainly functions to improve the high temperature performance of the aluminum alloy. In the inventive alloy, iron forms Al stable at high temperature with Al, Si₅FeSi intermetallic compound phase, and improves the high-temperature strength of the aluminum alloy. The content of iron is less than 0.3 wt%, the quantity of high-melting point intermetallic compounds formed in the alloy is small, and the high-temperature performance of the aluminum alloy is low; the content of iron is higher, and if the content is more than or equal to 2.5 wt%, coarse plate-shaped Al is easy to form in the aluminum alloy₅FeSi phase, which severely cracks the aluminum alloy matrix, resulting in reduced strength and fatigue of the aluminum alloySince the strength is sharply reduced, the content of iron (Fe) in the alloy is preferably: 0.5-2.2 wt%

The possible primary crystal silicon is modified by trace phosphorus (P0.01-0.05 wt%), so that the primary crystal silicon is granular, the cracking of thick flaky primary crystal silicon on an aluminum alloy matrix is avoided, and the fatigue performance of the aluminum alloy is improved;

trace zirconium (Zr0.05-0.2 wt%) forms Al in aluminum alloys₃The Zr nano-particles are mainly used for refining aluminum alloy grains and controlling recrystallization, and have a certain strengthening effect on the aluminum alloy.

In the aluminum alloy of the invention, the microalloying incidental elements Hf, Nb, Ti, V, Sc, Er and Yb are mainly used together with zirconium (Zr) to form Al₃The (Zr, M) nano composite particle phase refines the grain structure of the aluminum alloy, controls the recrystallization behavior of the grains and has certain strengthening effect on the aluminum alloy.

Drawings

FIG. 1 is a flowchart of a method for producing an aluminum alloy material according to the present invention

Detailed Description

Examples 1 to 9

Table 1 shows the chemical compositions of specific examples 1-9.

The preparation method comprises the following steps: the raw materials adopted for preparing the aluminum alloy are respectively pure metal simple substances and aluminum-based intermediate alloy, the metal simple substances are pure aluminum and pure zinc, other alloying elements are added in the manner of the aluminum-based intermediate alloy, and the purity of the pure metal and the aluminum-based intermediate alloy is not lower than 99.9%. The alloy is mixed according to the chemical composition and is smelted in a non-vacuum induction smelting furnace (or a resistance furnace), and the crucible is an alumina crucible. Putting required pure aluminum and various aluminum-based intermediate alloys into an alumina crucible, covering with a No. 1 solvent, performing power transmission and heating by using an induction furnace, heating to 800-.

TABLE 1 chemical composition of alloys of examples 1-9 Table (wt%)

Examples	Al	Zn	Si	Cu	Fe	P	Zr	Impurities
									1	Balance of	3.5	3.8	0.4	0.6	0.01	0.05	≤0.15
2	Balance of	4.0	6.0	2.2	0.5	0.045	0.15	≤0.15
									3	Balance of	4.5	5.5	1.8	0.8	0.04	0.15	≤0.15
4	Balance of	5.0	5.0	0.6	1.2	0.04	0.1	≤0.15
									5	Balance of	5.5	5.0	1.0	1.2	0.03	0.12	≤0.15
6	Balance of	6.0	4.5	1.3	0.9	0.03	0.12	≤0.15
									7	Balance of	6.0	4.0	1.6	1.5	0.03	0.12	≤0.15
8	Balance of	7.5	6.0	0.8	0.6	0.05	0.15	≤0.15
									9	Balance of	7.5	7.5	2.5	2.0	0.05	Zr+Sc＝0.2	≤0.15

Table 2 shows the Vickers hardness values of examples 1 to 9.

As shown in table 2: vickers hardness (Hv0.1) value at room temperature of the inventive aluminum alloy

Examples	1	2	3	4	5	6	7	8	9
										Hardness value	62	71	69	72	72	73	73	75	80

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.