累积叠轧法制备镁碳多层复合材料

Fabrication of Magnesium Carbon Multilayered Composites by Accumulative Roll-Bonding

当前镁合金的研究主要集中于镁合金及其复合材料的制备与加工,但对制备轻金属纳米多层复合材料的研究很少。通过在镁合金板之间插嵌镁粉与多壁碳纳米管(CNTS)的球磨混合粉,然后在一定温度下采用累积叠轧(ARB)的方法,制备镁碳多层复合材料。分别用扫描电镜和光学显微镜来表征累积叠轧过程中材料微观组织的演变。结果表明所采用的工艺制备出了层界面之间机械结合较好的镁碳多层复合材料,由于部分镁合金层之间存在融合现象,其理论层厚为685 nm,实际层厚约为4μm。另外,在反复动态再结晶和层界面对晶粒长大的阻碍作用的共同作用下,材料中较薄的镁合金层具有较细小的晶粒。

The current studies on magnesium alloy mainly focus on the preparation of magnesium alloy and its composite materials, and the preparation of light metal nano-multilayer composites is rarely studied. In this paper, magnesium carbon muhilayer of materials is prepared by applying seven cycles of accumulative roll bonding under certain temperature to magne- sium sheets coated with ball-milled Mg/CNTS powders. The evolution of the microstructure on the process of accumulative roll-bonding is respectively characterized by scanning electron microscope and optical microscope. The results show that the interface bonding of the magnesium carbon muhilayer of materials is mechanical bonding under the process used in this pa- per. The theoretical thickness of magnesium carbon multi-layer is about 685 nm, and the actual thickness is about 4 I^m due to partial magnesium alloy layer integration. In addition, in the role of repeated dynamic recrystallization and obstacles of layer interface on grain growth, the material in a thin layer of magnesium alloy has a fine grain.