粉末冶金法泡沫铝泡体连续性机理研究

发布时间：2018-03-08 09:26

本文选题：泡沫铝　切入点：粉末冶金法　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：泡沫铝是上世纪80年代兴起的一种新型材料,被称为结构-功能一体化材料。由于其特殊的结构特点,使其拥有许多传统材料无法媲美的特殊性质。它具有低密度、高孔隙率的结构特点,具有吸声、降噪、减震等功能性。泡沫铝目前在汽车、建筑、交通运输等领域应用较多。由于其独特性,使得近几年国内外对泡沫铝的研究和开发都十分活跃。本文采用粉末冶金法。即以纯铝粉、合金元素粉末、发泡剂(TiH_2粉末)为原料,通过挤压的方式制得泡沫铝预制体,最后在电阻炉内保温发泡制得泡沫铝材料。通过添加不同质量的Mg元素,研究了高添加量Mg元素对泡沫铝发泡行为的影响;探索了在不同体积倍数约束条件下泡沫铝在密闭型腔中的发泡行为以及不同镁元素添加量、不同发泡剂含量对泡沫铝结合发泡行为的影响。实验结果表明:高含量Mg元素可以改变泡沫铝基体内部氧化物相的组成;可以提高发泡过程中液相的熔体分数;可以在泡沫铝发泡早期改变泡体的形成方式;可以与基体中的Si元素反应生成微小Mg_2Si颗粒分散在孔壁中导致熔体的表观粘度增加。这些结果都对泡沫铝的发泡过程产生有利的影响,使最终的孔结构更加稳定。然而,过高的Mg元素也会对泡体结构产生不利影响,AlMg_4Si_7成分的泡沫铝发泡效果最佳。泡沫铝在密闭型腔中的发泡规律基本符合自由膨胀规律。随着Mg元素含量增加,泡沫铝结合发泡效果变得更好,当镁含量达到4Wt%时,泡沫铝基本能达到完全的冶金结合。
[Abstract]:Aluminum foam is a new type of material, known as structure-function integration material, which rose in -20s. Because of its special structural characteristics, it has many special properties that can not be compared with traditional materials. It has low density. High porosity structural characteristics, with sound absorption, noise reduction, shock absorption and other functions. Aluminum foam is widely used in automotive, construction, transportation and other fields. In recent years, the research and development of aluminum foam has been very active both at home and abroad. In this paper, the powder metallurgy method is used, that is, pure aluminum powder, alloy element powder, foaming agent TiH2 powder are used as raw materials, and the foamed aluminum preform is prepared by extrusion. Finally, the foamed aluminum material was prepared by heat preservation and foaming in resistance furnace. The effect of high mg content on foaming behavior of aluminum foam was studied by adding different mg elements. The foaming behavior of aluminum foams in the closed cavity under different volume multiple constraints and the addition of different magnesium elements were investigated. The experimental results show that the high content of mg can change the composition of the oxide phase in the aluminum foam matrix and increase the melt fraction of the liquid phase during the foaming process. The formation of foam can be changed in the early stage of foaming aluminum foam. The micro Mg_2Si particles dispersed in the pore wall can react with Si element in the matrix to increase the apparent viscosity of the melt. These results have a favorable effect on the foaming process of aluminum foam and make the final pore structure more stable. The foam aluminum foaming effect of AlMg4Si7 component is the best. The foaming law of aluminum foam in the closed cavity basically accords with the law of free expansion, and the content of mg element increases with the increase of mg content. The foaming effect of aluminum foam is better. When magnesium content reaches 4Wt%, aluminum foam can basically achieve full metallurgical bonding.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.4;TG146.21

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