(1. 河南科技大学 材料科学与工程学院，洛阳 471023；
2. 河南科技大学 河南省有色金属材料科学与加工技术重点实验室，洛阳 471023)
摘 要: 采用单辊快速凝固法制备出Mg80-xAlxCu15Y5(x=0，1)合金薄带，再将薄带在不同温度下进行退火处理，利用XRD、DSC和HRTEM分析Al元素对Mg80-xAlxCu15Y5(x=0，1)合金薄带的非晶形成能力及热稳定性的影响。结果表明：Al的加入使得Mg-Cu-Y合金的玻璃转变温度和初始结晶温度升高，过冷液相区宽度ΔTx因Al部分置换Mg而增大，约化玻璃转变温度Trg从0.616升至0.631，合金的非晶形成能力及热稳定性提高。随着退火温度的升高，Mg79Al1Cu15Y5合金的晶化率低于Mg80Cu15Y5合金的。当退火温度为523 K时Mg80-xAlxCu15Y5(x=0，1)合金均发生明显晶化，在非晶基体上弥散析出大量HCP-Mg和Mg2Cu纳米颗粒；当温度升高至573 K时，Mg79Al1Cu15Y5合金中有针状AlMg化合物相形成。
关键字: 镁基非晶合金；非晶形成能力；热稳定性；晶化
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Henan Key Laboratory of Advanced Non-ferrous Metals,
Henan University of Science and Technology, Luoyang 471023, China）
Abstract:Mg80-xAlxCu15Y5(x=0,1) alloy ribbons were prepared by single-roll rapidly solidification method. Then the samples were annealed at various temperatures. The effects of Al on the glass forming ability (GFA) and thermal stability of Mg80-xAlxCu15Y5(x=0,1) alloys were studied by XRD, DSC and HRTEM. The results show that Al addition enhances the glass transition temperature and the onset temperature of crystallization of Mg-Cu-Y alloy. The width of supercooled liquid region ΔTx is found to become larger with partial substitution of Mg by Al, and the reduced glass transition temperature Trg increases slightly from 0.616 to 0.631, which result in the improvement of the glass forming ability and thermal stability. With the increase of annealing temperature, the crystallization degree of Mg79Al1Cu15Y5 alloy is lower than that of Mg80Cu15Y5 alloy. The remarkable crystallization behavior of Mg80-xAlxCu15Y5(x=0,1) alloys occurs after being annealed at 523 K, while the dispersed precipitation of HCP-Mg and Mg2Cu nanoparticles takes place in the amorphous phase matrix. The acicular-shaped AlMg compound phase is formed in Mg79Al1Cu15Y5 alloy annealed up to 573 K.
Key words: Mg-based amorphous alloys; glass forming ability; thermal stability; crystallization
