航空泡沫铝合金的制备与吸能性能研究

发布时间：2018-01-22 19:27

本文关键词： 粉末冶金尿素泡沫铝合金热处理吸能　出处：《中国民航大学》2016年硕士论文　论文类型：学位论文

【摘要】：泡沫铝因其独特的结构特点而具有很多优异的性能,包括有隔音、降噪、吸能等;作为一种新型的功能材料,目前已经逐步应用于航空、航天、电子、能源等工业与科技领域。此外,2024和6061铝合金材料具有密度小、比强度高、耐腐蚀等特点,可经热处理强化,在航空、建筑、汽车制造等领域应用广泛。但是,目前关于泡沫铝合金的研究相对较少。本课题采用填加造孔剂法制备开孔泡沫材料,实验过程主要经过混粉-冷压-水浴-干燥-烧结五步完成。本论文研究并确定了制备过程中最佳工艺参数(冷压压力、烧结温度);制备了孔径范围为0.8~2.0mm,孔隙率为50%~70%的泡沫铝、2024泡沫铝合金和6061泡沫铝合金;系统研究了孔径和孔隙率对泡沫材料吸能性能的影响;通过对泡沫铝合金的T6热处理,研究了固溶时效对泡沫铝合金性能的影响,确定了6061泡沫铝合金的最优热处理工艺参数。研究结果表明:以圆球形尿素为造孔剂,采用填加造孔剂法可以制备孔隙率为50%~70%的开孔泡沫材料;该方法工艺流程简单,可以准确控制泡沫材料的孔径大小和孔隙率。制备开孔泡沫材料的最佳工艺参数为:冷压压力500Mpa,保压时间4min;泡沫铝的最佳烧结工艺为氩气保护下650oC烧结3h,2024泡沫铝合金最佳烧结工艺为氩气保护下570oC烧结3h,6061泡沫铝合金最佳烧结工艺为氩气保护下610oC烧结3h。当孔径小于2mm时,相同孔隙率下,孔径越大,泡沫材料的屈服强度越高;当孔径范围相同时,泡沫材料的屈服强度随着孔隙率的增大而降低,应力平台也随之下降。T6热处理并不能有效增强2024泡沫铝合金的吸能性能,反而使材料本身塑性降低,在受压过程中更易发生断裂甚至坍塌;6061泡沫铝合金经过固溶(510oC+1h)和时效(190oC+2h)T6热处理,材料的屈服强度达到19.08Mpa,应力平台达到17.30Mpa,吸能性能提高了28.2%,因此T6热处理可以有效增强6061泡沫铝合金的吸能性能。
[Abstract]:Because of its unique structural characteristics, aluminum foam has many excellent properties, including sound insulation, noise reduction, energy absorption and so on. As a new functional material, it has been gradually applied in the fields of aviation, aerospace, electronics, energy and other industries and science and technology. In addition, 2024 and 6061 aluminum alloy materials have low density and high specific strength. Corrosion resistance can be strengthened by heat treatment, widely used in aviation, building, automobile manufacturing and other fields. At present, there is relatively little research on the foam aluminum alloy. In this paper, the porous foam materials are prepared by the method of adding pore-forming agent. The experimental process is mainly completed by mixing powder, cold pressing, water bath, drying and sintering. In this paper, the optimum process parameters (cold pressing pressure, sintering temperature) are studied and determined. The foamed aluminum alloy 2024 and 6061 foamed aluminum alloy with a pore size of 0.8 ~ 2.0 mm and a porosity of 50 ~ 70% were prepared. The effects of pore size and porosity on the energy absorption properties of foams were systematically studied. The effect of solution aging on the properties of foamed aluminum alloy was studied by T6 heat treatment. The optimum heat treatment parameters of 6061 foamed aluminum alloy were determined. The results showed that spherical urea was used as pore-forming agent. The porous foams with a porosity of 50% or 70% can be prepared by filling with pore-making agent. The process is simple and the pore size and porosity of foamed materials can be accurately controlled. The optimum process parameters for the preparation of porous foams are as follows: cold pressing pressure 500Mpa, holding pressure time 4 mins; The optimum sintering process of aluminum foam is that 650oC sintered for 3h and 2024 for 3h under argon protection. The optimum sintering process is 570oC sintered for 3h under argon protection. The optimum sintering process of 6061 foamed aluminum alloy is 610oC sintered in argon for 3 h. When the pore diameter is less than 2mm, the larger the pore size is, the higher the yield strength of foamed aluminum alloy is. When the pore size range is the same, the yield strength of foam material decreases with the increase of porosity, and the stress platform decreases. T6 heat treatment can not effectively enhance the energy absorption performance of 2024 foamed aluminum alloy. On the contrary, the plasticity of the material itself is reduced, and it is easier to fracture or even collapse in the process of compression. The yield strength of 6061 foamed aluminum alloy was 19.08 MPA after heat treatment with solution of 510oC 1h) and aging of 190oC 2hu T6. The stress platform reaches 17.30Mpaand the energy absorption property is improved by 28.20.Therefore, T6 heat treatment can effectively enhance the energy absorption performance of 6061 foamed aluminum alloy.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V252.2

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