(1. 大连理工大学 材料科学与工程学院，大连 116024；
2. 大连理工大学 三束材料改性国家重点实验室，大连 116024)
摘 要: 利用电磁搅拌技术，结合悬浮铸造方法，在浇铸AZ61镁合金的过程中加入微纳米颗粒CaC2，使CaC2弥散分布于母相金属液中，促进合金形核，改善合金铸造组织形态和分布，提高合金的力学性能。结果表明：利用电磁−悬浮铸造制备的镁合金，其显微组织细化，晶间β相细小并且网状结构减少，当CaC2悬浮剂加入量(质量分数)为0.36%时，镁合金的细化效果最佳，其晶粒最小尺寸为75 μm，抗拉强度为211.4 Pa，伸长率为8.5%，与普通金属型铸造制备的镁合金相比，晶粒尺寸减小64.3%；抗拉强度提高约24.2%；伸长率提高46.6%。
关键字: AZ61镁合金；CaC2；电磁−悬浮；显微组织；力学性能
（1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024;
2. State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams,
Dalian University of Technology, Dalian 116024, China）
Abstract: The electromagnetic suspension casting of AZ61 wrought magnesium alloy was studied using electromagnetic stirring technique and the suspension casting during the casting process. The electromagnetic suspension casting not only can diffuse CaC2 powders distribution into the melt evenly, but also can refine the development of dendrite. The results show that electromagnetic suspension casting is found to be effective on refining the microstructure of magnesium materials, thinning the β-Mg17Al12 and improving the distribution uniformity of β-Mg17Al12 phase. The 0.36% CaC2 addition refines the grains most effectively, and the size is 75 μm. The ultimate tensile strength of alloys is 211.4 MPa, and the elongation is 8.5%. The grain size decreases by 64.3%, and the ultimate tensile strength and the elongation of alloys increase by 24.2% and 46.6% respectively compared with those of the die-casting Mg alloys.
Key words: AZ61 magnesium alloy; CaC2; electromagnetic suspension; microstructure; tensile properties
