Method for preparing foamed aluminium and aluminum alloy by secondary foaming with novel blowing agent

Abstract

The invention belongs to the preparation field of foaming metal and discloses a method for adopting the secondary foaming behavior of a novel foaming agent to prepare a foamed aluminum and an aluminum alloy; the steps include: 1, heating the aluminum or the aluminum alloy until smelting and preserving the temperature for 30min under the temperature of 660 to 720 DEG C, adding the powder of lime carbonate accounting for 0.5 to 3.0 percent of the weight portions of an aluminum liquor and stirring for 5 to 15 min with a rotating speed of 400 to 600rpm; 2, adding the powder of lime carbonate accounting for 0.5 to 4.0 percent of the weight portions of the aluminum liquor and after stirring for 3 to 7 min with a rotating speed of 700 to 1200rpm, quickly cooling and shaping; the hole rate is lower than that of the spherical hole foamed aluminum of 65 percent or an alloy blank; 3, preserving the temperature of the spherical hole foamed aluminum blank for 10 to 15min under the temperature of 300 to 570 DEG C; 4, arranging the spherical hole foamed aluminum blank into a die and leading the lime carbonate in the blank to be secondarily decomposed by heat under the temperature range of 810 to950 DEG C to generate the secondary foaming behavior and to be fasted cooled to obtain the foam, the aluminum and the product of the product of the irregular-shaped part of the aluminum alloy.

Description

technical field [0001] The invention relates to a method for preparing closed-cell foamed aluminum and foamed aluminum alloy, in particular to a method for preparing foamed aluminum and foamed aluminum alloy by using a novel foaming agent through secondary foaming. Background technique [0002] Aluminum foam and aluminum alloy are a new type of aluminum-based metal material containing a large number of uniform closed pores. Due to its unique physical structure, it has light weight (ρ<1), high specific strength and specific stiffness, and has sound insulation and insulation Various properties such as heat, flame retardancy, damping, impact energy absorption, and electromagnetic shielding have realized the lightweight and multifunctional structural materials, so they have broad application prospects. In the high-tech fields such as aerospace and aerospace, foamed aluminum and alloy special-shaped parts have become the frontier hotspots of international material research as ...

AI Technical Summary

Problems solved by technology

In the high-tech fields such as aerospace and aerospace, foamed aluminum and alloy special-shaped parts have become the frontier hotspots of international material research as ultra-light materials. It is difficult to prepare special-shaped parts by melt foaming, and the production of foamed aluminum special-shaped parts by powder metallurgy is costly. , Disadvantages of unstable process

Traditional aluminum foam uses titanium hydride as the foaming agent, which has the advantages of mature technology and large gas production. It begins to decompose at 340°C, and it decomposes obviously above 400°C. Bubbles form rapidly in aluminum melt (660°C), but it does not work at high temperatures. The bottom is extremely unstable, so the titanium hydride foaming agent needs to be subjected to physical grinding, heating oxidation, gel wrapping, metal wrapping and other artificial passivation treatments before use. The processing technology requires high requirements and the process parameters are difficult to master, which further increases production Cost, especially when it is used to prepare secondary foamed aluminum and aluminum alloy billets, the combustion and decomposition are seriously difficult to control, and it is difficult to ensure that a sufficient amount of titanium hydride remains in the billet, resulting in the failure of secondary foaming, so carbonic acid is considered Salt as a blowing agent to prepare aluminum foam and aluminum alloy has important application prospects

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