(1. 沈陽工業(yè)大學 材料科學與工程學院，沈陽 110178；
2. 北京航空航天大學 材料科學與工程學院，北京 100083)
摘 要: 采用銅模鑄造制備直徑為3 mm的Mg70−xZn25Ca5Cux(x=1, 2, 3.5, 5)系列合金。分別采用掃描電鏡(SEM)、X射線衍射儀(XRD)、力學性能試驗裝置研究合金的顯微組織、相組成和鑄態(tài)樣品的壓縮性能，并對斷口形貌進行分析。結果表明：Mg69Zn25Ca5Cu1可以形成直徑為3 mm的非晶合金，其強度和塑性應變分別為690 MPa和1.7%。與Mg-Zn-Ca合金相比，其非晶形成能力和塑性應變均有提高。同時這也是目前在直徑大于2 mm的Mg基非晶合金中所發(fā)現(xiàn)的最大塑性應變量。
關鍵字: Mg-Zn-Ca合金；Cu；非晶形成能力；力學性能
Mg-Zn-Ca alloys
（1. School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110178, China;
2. School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,
Beijing 100083, China）
Abstract: Mg70−xZn25Ca5Cux(x=1, 2, 3.5, 5) as-cast alloys with 3 mm in diameter were produced by using copper mold casting method. The microstructures, phase constitutes and mechanical properties of as-cast samples were investigated by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and compression tester. The fracture surfaces were also analyzed by SEM. The results show that the critical sample size for glass formation, the fracture strength and the plastic strain of Mg69Zn25Ca5Cu1 alloy are 3 mm in diameter, 690 MPa and 1.7%, respectively. Both of the glass forming ability and the plastic deformation are improved obviously compared with Mg-Zn-Ca alloys. Up to now the plastic strain is the largest one in the samples with diameter larger than 2 mm for Mg-based bulk metallic glasses.
Key words: Mg-Zn-Ca alloy; Cu; glass forming ability; mechanical properties
