High-strength aluminum alloy for additive manufacturing and preparation method of high-strength aluminum alloy powder

Abstract

The invention provides a high-strength aluminum alloy for additive manufacturing and a preparation method of high-strength aluminum alloy powder. The high-strength aluminum alloy powder is prepared byadopting a gas atomization process. The preparation method comprises the following steps of: firstly, melting an Al-Si-Zn-Cu-Mg-X alloy prefabricated ingot by adopting a medium frequency induction furnace, then powdering by adopting a supersonic speed gas atomization process, sieving and preparing powder of different specifications for additive manufacturing. A test sample obtained by adopting the high-strength aluminum alloy powder through additive manufacturing has compact texture without crack defects, the strength of extension exceeding 500MPa and the elongation exceeding 3%; the strengthperformance of the test sample is obviously superior to the strength performance of additive manufacturing test samples of AlSi10Mg, AlSi7Mg and AlSi12; and the performances of the test sample are also superior to the performances of additive manufacturing test samples of conventional 2000 series and 7000 series alloys. The alloy powder can be used for preparing aluminum alloy parts with compacttexture, complicated shapes and high strength in an additive manufacturing method to meet the requirements of use occasions on high specific strength and complicated shapes in the fields of aviation,spaceflight and automobiles.

Description

technical field [0001] The invention relates to a preparation method of a high-strength aluminum alloy for additive manufacturing and powder thereof, and belongs to the technical field of aluminum alloy powder for metal additive manufacturing. Using the powder, the tensile strength of the sample processed by laser melting additive manufacturing process exceeds 500MPa, the elongation exceeds 3%, and the cost is relatively low. Background technique [0002] In the past five years, with the application of high-power lasers, metal additive manufacturing technology has achieved a breakthrough and rapid development. Metal additive manufacturing uses high-quality metal powder as raw material, adopts CAD model design and computer control, uses high-power laser, and manufactures parts through layer-by-layer melting. Through the use of high-power lasers and suitable process parameters, the relative density of the parts obtained through additive manufacturing can reach more than 99.5%...

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Problems solved by technology

[0004] The strength of the traditional high-strength 2000-series and 7000-series wrought aluminum alloys can reach 500-600MPa, but because of its wide solidification range, poor welding performance and high tendency to hot cracking

At present, the SLM manufacturing test results of these traditional high-strength aluminum alloys are not satisfactory, and the prepared samples often have crack defects, resulting in their tensile properties and fatigue properties being significantly lower than those of traditional deformed aluminum alloys, even lower than those of Al-Si The performance of the alloy

In recent years, Airbus has prepared AlMg4.5ScZrMn alloy (commercial code name) whose mechanical properties are comparable to those of deformed aluminum alloys (see: [1] A.B.Spieringset.al, Microstructure and mechanical properties of as-processed scandium modified aluminum using selective laser melting .CIRP Annals-Manufacturing Technology 65(2016) 213-216; [2] Bronke Renchowski (Airbus Defense and Space Co., Ltd.), Scandium-containing aluminum alloys for powder metallurgy technology, Chinese Patent : 201611272966.6), but because the content of the expensive element Sc in the alloy reaches more than 0.6%, the price of the alloy powder is very high, which is 3 to 4 times the price of Al-Si alloy powder, which limits its wide application

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