Ultra-fine aluminum-silicon alloy powder with low oxygen content and production method thereof

Abstract

The invention relates to an ultra-fine aluminum-silicon alloy powder with low oxygen content and a production method thereof. The method comprises the following steps: melting aluminum with high purity greater than 99.85 percent and silicon with purity greater than 99.6 percent, which serve as raw materials, into an aluminum-silicon alloy solution under high temperature, and jetting the alloy solution into an atomization settling chamber protected by high-purity nitrogen (with purity greater than 99.99 percent) under conditions of high temperature of 450 to 650 DEG C, high-purity nitrogen (with purity greater than 99.99 percent), jetting pressure of 6 to 15 MPa and the gas / metal mass flow rate of 5-12: 1, quickly cooling the alloy solution through high-speed cyclic flowing of the high-purity nitrogen in a system, grading the alloy solution through pipeline conveying, centrifugating and cyclone systems, and collecting to obtain the spherical aluminum-silicon alloy powder with the particle size of 1 to 15 microns, wherein the weight percentage of each fraction can be adjusted as required via changing parameters of a proudctio process. The oxygen content of the aluminum-silicon alloy powder is less than 2,000 ppm, and the silicon content is 1 to 80 percent; when the aluminum-silicon alloy powder is used for preparing back field slurry of a silicon solar battery, so that the silicon solar battery can achieve satisfactory performance.

Description

technical field [0001] The invention belongs to the technical field of powder metallurgy, and in particular relates to a method for preparing ultra-fine aluminum-silicon alloy powder with low oxygen content. The alloy powder is mainly used to manufacture silicon solar back field slurry. Background technique [0002] In recent years, as the use of solar energy has been paid more and more attention, the production of solar panels has increased rapidly, and the production is mainly concentrated on monocrystalline silicon and polycrystalline silicon solar panels. P-type Si is used as the back electrode (positive electrode) of solar cells. The conductive material that forms close ohmic contact with it is currently widely used to print aluminum paste on the Si substrate and then sinter it. The aluminum paste used in printing is composed of a conductive phase (aluminum powder and aluminum-silicon alloy powder), an inorganic binder phase (glass powder), additives, and a carrier. The...

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Problems solved by technology

With a nozzle diameter of 8mm, a pressure of 4-8MPa, and 300°C nitrogen jet crushing, the Al-Si-Cu alloy powder is obtained, with a particle size range of 20-60μm and an oxygen content of 0.41%. This alloy powder is used as Subsequent hot extrusion to prepare high wear-resistant block alloys is not suitable as a conductive material in the back field slurry of silicon solar cells, because: (1) contains a large amount of impurity elements, which will significantly reduce the performance of solar cells; (2) powder particles If the diameter is too large, the close contact between conductive powders cannot be guaranteed; (3) If the oxygen content is too high, it will easily lead to too large contact resistance between metal powders, which will significantly reduce the performance of solar cells

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