Method for preparing aluminum powder and aluminum alloy powder through water atomization

Abstract

The invention discloses a method for preparing aluminum powder and aluminum alloy powder through water atomization. The method comprises the following steps of melting aluminum ingots or aluminum alloy by using a guide crucible, and ensuring that the temperature of a melt is kept between 700DEG C and 1,100DEG C for 30 to 60 minutes; meanwhile, heating the guide crucible; pouring molten aluminum alloy into the guide crucible, and allowing the molten aluminum alloy to continuously flow out along a guide tube at the bottom of the guide crucible; starting a high pressure water pump, controlling the pressure of high pressure current to be 2-16MPa and the water temperature to be 10-40DEG C, enabling the high pressure current into which an inhibitor is added and of which the pH is 4.0-5.0 to be sprayed by nozzles on the top of an atomizing chamber, and atomizing the molten aluminum to obtain the aluminum and aluminum alloy powder. According to the method, the aluminum powder can be safely produced through the water atomization; compared with aluminum powder prepared through gas atomization, the aluminum powder prepared through the water atomization is finer in particle size, large in specific surface area and high in activity; moreover, the water atomization is higher in cooling speed, the extended solid solubility of alloy elements is greatly improved, and aluminum alloy which is hardly prepared by a casting process is produced. In addition, the cost of preparing the aluminum powder through the water atomization is lower than the cost of preparing the aluminum powder through the gas atomization, and the method is suitable for large-scale production.

Description

technical field [0001] The invention relates to the field of powder metallurgy, and relates to a method for preparing aluminum powder and aluminum alloy powder by water atomization. Background technique [0002] Aluminum powder is an important industrial raw material, widely used in metal flash coatings, solid rocket propulsion, conductive coatings and powder metallurgy industries. At present, when domestic and foreign manufacturers produce aluminum powder, they all use gas atomization to produce, and the gas used is generally inert gas such as nitrogen and argon for atomization. The main disadvantages of using gas atomization to prepare aluminum powder are: 1. The cooling rate is low, and the cooling rate of general gas atomization is 10 2 -10 3 K / s; Second, it is difficult to prepare ultrafine powder by gas atomization. The particle size of aluminum powder prepared by gas atomization is generally coarse, and it is difficult to prepare ultrafine aluminum powder below 5 μm...

AI Technical Summary

Problems solved by technology

The main disadvantages of using gas atomization to prepare aluminum powder are: 1. The cooling rate is low, and the cooling rate of general gas atomization is 10 2 -10 3 K / s; Second, it is difficult to prepare ultrafine powder by gas atomization. The particle size of aluminum powder prepared by gas atomization is generally coarse, and it is difficult to prepare ultrafine aluminum powder below 5 μm; Third, the cost of gas atomization is relatively high

The water atomization technology has not been applied to the preparation of aluminum powder and aluminum alloy powder. The main reasons are as follows: 1. The activity of aluminum powder is high, and it is easy to react with water to produce hydrogen, which is prone to the risk of explosion; 2. During the process of water atomization, , the reaction between aluminum powder and water is difficult to control, which will cause severe oxidation of aluminum powder and affect the activity of the prepared aluminum powder