Lead-free brass alloy

A lead-free brass and brass alloy technology, applied in the field of brass alloys, can solve the problems of material embrittlement, brass tube perforation, poor machinability, etc.

Inactive Publication Date: 2011-08-03
MODERN ISLANDS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] On the other hand, when the zinc content in the brass exceeds 20% by weight, the corrosion phenomenon of dezincification (dezincification) is prone to occur, especially when the brass is exposed to an environment with high chloride ions, such as seawater environment, the dezincification corrosion phenomenon will be accelerated happened
Dezincification will seriously damage the structure of the brass alloy, reduce the surface strength of the brass product, and even cause the brass tube to perforate, greatly shorten the service life of the brass product, and cause problems in application
[0005] In order to overcome the above problems of high lead content and dezincification, the industry continues to develop new copper alloy formulations, in addition to the necessary components of copper and zinc, such as Taiwan Patent TW 421674, US Patent US7,354,489, US 2007-0062615, US 2006 -0078458, US 2004-023441, and US2002-069942 teach lead-free copper alloy formulations with addition of silicon (Si) and other elements, but the above alloys still have the disadvantage of poor machinability
Chinese patent CN 10144045 discloses a lead-free copper alloy formula with aluminum, silicon, and phosphorus as the main alloying elements. Although the alloy can be used for casting, it has the disadvantage of poor machinability, and its processing efficiency is much lower than that of lead-containing brass, so it is not suitable for mass production
Chinese patents CN101285138 and CN 101...

Method used

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Examples

Experimental program
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Embodiment

[0036] A copper gravity casting machine is used to cast castings, and copper alloys with different additives are tested to verify the improvement efficiency of the ratio of added elements. For each test process, fixed casting shapes, sand core particles and hardness, resin gas generation, resin and curing agent materials are used. First add the proportions of each component to the induction furnace. After the brass alloy reaches a certain molten state (hereinafter referred to as molten copper), the composition is checked by a spectrometer. When the composition of the test is met, the temperature of the molten metal is increased and maintained at 1030 Between 1050°C and 150°C to 170°C mold temperature, melting begins.

[0037] Use a metal gravity casting machine with a sand core and a gravity casting mold for casting. The feeding amount for each casting is 1 to 2 kg, the casting time is controlled within 3 to 5 seconds, and the cooling time in the fixed mold is controlled. Afte...

Embodiment 1

[0045] According to the composition ratio shown in Table 1, the lead-free brass alloy sample 1 of the present invention was obtained according to the above steps, and the quality inspection and analysis results and the total production pass rate are recorded in Table 1.

Embodiment 2

[0048] Repeat the steps of Example 1, adjust the alloy composition as shown in Table 1, increase the proportion of iron in the alloy to 0.613% by weight, and match the manganese composition of 0.158% by weight to obtain the lead-free brass alloy sample 2 of the present invention. The results of quality inspection and analysis and the total pass rate of production are recorded in Table 1.

[0049] The metallographic structure distribution of lead-free brass alloy sample 2 of the present invention is as follows Figure 3A As shown, compared with sample 1, the crystal grains of sample 2 are thinner and shorter, the grain size of the crystal grains is about 35 to 40 microns, and it has better material toughness. Such as Figure 3B As shown, there is no obvious crack defect on the surface of the casting embryo. After the finished product is polished, almost no cracks can be observed on the surface, such as Figure 3C shown.

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Abstract

The invention relates to a lead-free brass alloy containing the following components in percentage by weight: 0.3%-0.8% of aluminum, 0.01%-0.4% of bismuth, 0.05%-0.15% of ferrum and more than 96% of copper and zinc, wherein the copper content of the lead-free brass alloy is 58%-75%. The brass not only accords with the standard of the lead-free alloy environmental protection laws and regulations that the lead content is less than 0.25%, but also contains 0.05%-1.5% of ferrum and less than 0.4% of bismuth, so that the production cost can be reduced, the defects of cracks, slag inclusion and the like existing in castings can also be reduced, and therefore, the yield and the qualified rate of the product are effectively improved.

Description

technical field [0001] The invention relates to a brass alloy, in particular to a lead-free brass alloy with a lead content of less than 0.25% by weight. Background technique [0002] The main components of brass are copper and zinc, usually in a ratio of about 7:3 or 6:4, and usually contain a small amount of impurities. In order to improve the properties of brass, the known brass often contains 1 to 3% lead by weight to achieve the mechanical properties required by the industry, and thus become an important material in industry, widely used in metals for pipelines, faucets, water supply / drainage systems Devices or metal valves and other products. [0003] However, with the rise of environmental protection awareness, the impact of heavy metals on human health and environmental pollution has gradually been paid attention to. Therefore, restricting the use of lead-containing alloys has become a current trend. Japan, the United States and other countries have successively re...

Claims

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Application Information

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IPC IPC(8): C22C9/04
Inventor 吴威德罗文麟林庚立吕鸿庆
Owner MODERN ISLANDS
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