High-content chromium metal additive for aluminum alloy production and preparation method thereof

Abstract

The invention belongs to the field of aluminum alloy additives, and discloses a high-content chromium metal additive for aluminum alloy production and a preparation method thereof. The high-content chromium metal additive takes the shape of a cake or a rugby mainly pressed by chromium powder, aluminum powder and a fluxing agent, wherein the chromium powder and the aluminum powder are respectively crushed under the protection of inert gas. The high-content chromium metal additive further comprises a surface active agent; and the mass percentages of all the components are as follows: 90-97% of chromium powder, 0-9.38% of aluminum powder, 0.01-5% of fluxing agent, and 0.5-2% of surface active agent. In the additive, the content of the chromium metal element is highest to 97%; the chromium additive is low in melting temperature; the melting temperature is low to 670 DEG C; the melting time is short; the melting can be realized by 10-15 minutes; and the recovery rate of the chromium metal element is high above 98%.

Description

technical field [0001] The invention belongs to the field of aluminum alloy additives, and in particular relates to an aluminum alloy chromium additive and a preparation method thereof. Background technique [0002] With the continuous development of aluminum processing and aluminum alloy industry, the development of aluminum alloy is listed as a key development technology, and alloying is an important part of the aluminum alloy production process. The dissolution of alloying elements in molten aluminum is an important process of alloying. The dissolution of elements is closely related to their properties, and is controlled by the destruction of the bonding force of the solid-state structure of the added elements and the diffusion speed of atoms in the aluminum liquid. Alloying elements commonly used in aluminum alloys are: silicon, iron, copper, magnesium, nickel, zinc, vanadium, etc. Some alloying elements with low melting point or high solubility, such as magnesium and ...

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Problems solved by technology

In addition, due to the low content of alloy elements contained in the master alloy, the amount of master alloy used will be relatively large in the calculation of weighing. In order to ensure the temperature of the molten master alloy, the amount of master alloy added each time should not be too much. If the amount is too much, the temperature of the aluminum melt will drop, and the intermediate alloy cannot be melted. Therefore, when producing the same type of aluminum alloy, it is necessary to add a small amount of the intermediate alloy to the aluminum melt many times, so that it will The following problems are caused: 1. The time required to melt the intermediate alloy is too long; 2. The amount of impurities generated by the reaction of the aluminum melt with oxygen, hydrogen, carbon, moisture and other substances in the atmosphere for a long time increases, resulting in an increase in the amount of impurities in the aluminum alloy. The quality is reduced; 3. Long melting time will increase energy consumption, which will increase the burning loss and air absorption of aluminum melt

However, this method needs a large amount of flux to realize, so in each additive product, the content of manganese, iron and chromium can only reach about 85%. If the content of manganese, iron and chromium in the additive product is increased to 90% or more, the amount of the corresponding flux will be reduced. After the product is added to the molten aluminum, the manganese, iron, and chromium in the additive cannot be completely melted; Additive products are compressed into cakes or balls with a higher density, usually greater than 5.0g / cm 3 , but for additive products with higher density, there are the following problems: 1. The melting is relatively slow, and the melting time is usually more than 20 minutes, and the melting time is long; 2. The additives added to the aluminum melt tend to sink to the bottom. It will cause the melting speed of chromium powder to slow down, and on the other hand, it will lead to uneven dispersion of chromium powder after dissolution; 3. A dense protective film will be formed on the surface of the denser additive product during the melting process, resulting in the inability to continue melting inside, so that The recovery rate will be low, the highest can only reach about 90%

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