泡沫铝芯夹层板的真空发泡制备研究
发布时间：2019-06-07 17:37
【摘要】：泡沫铝芯夹层板由泡沫铝芯和金属面板组成,具有低密度、高阻尼、高比强度、高吸能以及电磁屏蔽等性能,并在很大程度上解决了单一泡沫铝强度低的缺点。鉴于目前泡沫铝芯夹层板存在泡沫铝芯与表面层界面连接不够理想,力学性能受表面层与泡沫芯结合方式制约等问题,本文提出了一种新型的近净成型制备泡沫铝芯夹层板的方法——真空发泡法,并对真空发泡法制备泡沫铝芯夹层板进行了研究,主要研究结果如下：(1)以Al-Si12-Ca3合金为原料,采用真空发泡法成功制备出厚度20-35mm的泡沫铝芯夹层板,夹层板表面层厚度0.5-1mm,内部孔结构均匀,孔径2.5-7mm,孔隙率75-85%,表面层与泡沫铝芯为冶金结合。(2)制备了含有初始气孔的可真空发泡熔体,获得的最佳初始气孔制备工艺参数为：TiH2添加量0.3%,熔体温度630℃,发泡剂分散搅拌速度2000r/min,分散搅拌时间120s。将可真空发泡熔体在真空作用下充型制备泡沫铝芯夹层板,其最佳真空发泡工艺为：真空度10Pa,真空发泡时间30s。(3)对真空发泡法制备的泡沫铝芯夹层板进行拉伸性能和三点弯曲性能测试,结果表明：孔隙率对泡沫铝芯夹层板力学性能影响较大,孔隙率从75%增大到85%,抗拉强度从18.89MPa降低到10.73MPa,抗弯强度从16.20MPa降低到8.73MPa。与相同孔结构的泡沫铝芯相比,泡沫铝芯夹层板相比泡沫铝芯抗拉强度提高了24.57%,抗弯强度提高了13.67%。(4)初始气孔气泡形核以非均匀形核为主,形核速率与H2分子浓度和形核质点数成正比。真空作用下,熔体气泡内部气压与真空罐内气压形成的压力差是气泡膨胀的动力,真空罐内气压释放越快,气泡膨胀越快。整个气泡膨胀过程中,气泡膨胀速率先慢后快。(5)泡沫熔体的外层胞壁在真空膨胀作用及模具作用下,相邻胞壁互相挤压使其多边形化和平整化,熔体首先在模具表面结壳凝固形成表面层,自然冷却得到泡沫铝芯夹层板。
[Abstract]:The foam aluminum core sandwich plate is composed of foam aluminum core and metal panel, which has the properties of low density, high damping, high specific strength, high energy absorption and electromagnetic shielding, and solves the disadvantage of low strength of single aluminum foam to a great extent. In view of the fact that the interface connection between the foam aluminum core and the surface layer is not ideal, and the mechanical properties of the foam aluminum core sandwich plate are restricted by the combination mode of the surface layer and the foam core, and so on, In this paper, a new method of preparing foam aluminum core sandwich plate by near net molding, vacuum foaming method, is proposed, and the preparation of foam aluminum core sandwich plate by vacuum foaming method is studied. The main results are as follows: (1) the foam aluminum sandwich plate with thickness 20-35mm was successfully prepared by vacuum foaming method with Al-Si12-Ca3 alloy as raw material. The surface layer of the sandwich plate is 0.5 mm thick and the internal pore structure is uniform. The pore size is 2.5 脳 7 mm, the porosity is 75 鈮，
本文编号：2494971
[Abstract]:The foam aluminum core sandwich plate is composed of foam aluminum core and metal panel, which has the properties of low density, high damping, high specific strength, high energy absorption and electromagnetic shielding, and solves the disadvantage of low strength of single aluminum foam to a great extent. In view of the fact that the interface connection between the foam aluminum core and the surface layer is not ideal, and the mechanical properties of the foam aluminum core sandwich plate are restricted by the combination mode of the surface layer and the foam core, and so on, In this paper, a new method of preparing foam aluminum core sandwich plate by near net molding, vacuum foaming method, is proposed, and the preparation of foam aluminum core sandwich plate by vacuum foaming method is studied. The main results are as follows: (1) the foam aluminum sandwich plate with thickness 20-35mm was successfully prepared by vacuum foaming method with Al-Si12-Ca3 alloy as raw material. The surface layer of the sandwich plate is 0.5 mm thick and the internal pore structure is uniform. The pore size is 2.5 脳 7 mm, the porosity is 75 鈮，
本文编号：2494971
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