High-strength antifriction aluminum alloy and preparation method thereof

Abstract

The invention relates to high-strength antifriction aluminum alloy comprising the components of, by weight, 1.0%-9.0% of bismuth, 2.0%-8.0% of copper, 0.3%-1.7% of manganese, 0.2%-1.7% of silicon, 0.3%-2.2% of magnesium, 0-0.7% of impurities, and the balance aluminum. According to the high-strength antifriction aluminum alloy, bismuth, copper, manganese, silicon, magnesium and other elements are added, strength and antifriction performance of an aluminum substrate are improved through alloying, and the requirement of a high-pressure gear pump is fully met. The grain size grade index of the microstructure of the prepared aluminum alloy reaches 7-8 grade, the tensile strength can reach 450-470 Mpa, and the friction coefficient is smaller than 0.02. The mechanical property of the aluminum alloy material is improved, and meanwhile, good processability, low surface roughness and other advantages are achieved. Meanwhile, the components of the aluminum alloy do not contain heavy metal, harm to human bodies and the environment due to the fact that heavy metal, such as lead, is widely used in existing aluminum alloy materials is avoided, and important positive significance is achieved for facilitating green and environment-friendly production.

Description

technical field [0001] The invention relates to the field of aluminum alloys, in particular to a high-strength anti-friction aluminum alloy and a preparation method thereof. Background technique [0002] In the hydraulic parts industry, gear pumps are products with a large quantity and a wide range. The positioning of the gears in the gear pump and the sealing of the end discharge are usually ensured by aluminum alloy bearing sleeves, copper alloy or steel-tin bronze sintered composite bimetallic side plates. Gear oil pump, the prior art has the following problems: [0003] Because if copper alloy or steel-tin bronze sintered composite bimetal is used, not only the weight is relatively large, but also a large amount of copper material needs to be consumed, and the production cost is too high. Therefore, most of the gear pump materials are made of aluminum alloy at present. Under the working conditions of high pressure and high speed, the working temperature is relatively h...

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Problems solved by technology

[0003] Because if copper alloy or steel-tin bronze sintered composite bimetal is used, not only the weight is large, but also a large amount of copper material needs to be consumed, and the production cost is too high

Therefore, most of the gear pump materials are made of aluminum alloy at present. Under the working conditions of high pressure and high speed, the working temperature is relatively high. Due to the different expansion coefficients of iron, copper and aluminum, it is easy to cause a drop in matching accuracy. , leading to a decrease in the overall efficiency of the gear pump

[0004] Existing aluminum alloy materials usually use Si as a strengthening element, but the strength performance is not high. For example, the SAE788 aluminum alloy commonly used for bearing bushes, its main elements are: Sn: 6%-8.8%, Pb: 1.5%-2.5%, Si: 2.25%-2.75%

Its tensile strength (6b) is only 138-159Mpa, which cannot meet the strength and friction performance requirements of high-pressure gear pumps. At the same time, there is heavy metal lead in it, which does not meet the current environmental protection production requirements

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