Mg含量和冷速对Mg-Cu-Zn-Y非晶复合材料微观结构及腐蚀行为的影响

Effects of Mg Content and Cooling Rate on Microstructure and Corrosion Behavior of Mg-Cu-Zn-Y Bulk Metallic Glass Composites

摘要:

采用水冷铜模法和水淬法制备得到Mg65+x(Cu0.66Y0.34)30- xZn5 (x=5，10，15)非晶及其复合材料。并通过XRD、SEM对材料结构进行表征，研究Mg含量和冷却速度对样品微观结构的影响。结果表明：由水冷铜模法得到的x=5样品为单一非晶，x=10和15样品是由非晶相与Mg固溶体相组成的非晶复合材料。而利用冷速较低的水淬法得到的样品为非晶复合材料，其主要由Mg，Mg2Cu，MgZnY和非晶相组成。通过研究合金在NaCl中性溶液中的腐蚀行为，发现随着Mg含量的增加，样品的耐腐蚀性能有所下降。并且对于同成分的合金，由冷速较快的水冷铜模法得到的样品耐蚀性相对较好。

Abstract:

Mg65+x(Cu0.66Y0.34)30-xZn5 (x=5, 10, 15) alloys and their matrix composites were prepared by water-cooled copper mold casting and water quenching. The microstructures of the bulk samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) in order to study the effects of Mg content and cooling rate. The results show that the alloy at x=5 prepared by water-cooled copper mold casting exhibits a fully glass structure. And the alloys at x=10 and 15 are mainly composed of the amorphous phase and Mg solid solution phase, which are amorphous composites. However, the amorphous composite materials prepared by low-cooling-rate water quenching mainly consist of Mg, Mg2Cu, MgZnY and the amorphous phase. The corrosion behavior of the alloys was studied in NaCl neutral solution. The results show that the precipitation of the crystal phase is increased with the increase of the Mg content, but at the same time the decrease of the corrosion resistance occurs. Furthermore, with the same composition, the samples prepared by water cooled copper mold casting at a high cooling rate have the best corrosion resistance while the samples prepared by water quenching at a low cooling rate have the worst.