Mg-TM-Ln型镁基纳米结构材料研究  

Study on Mg-TM-Ln Type Nanostructured Materials

作　　者：孙国元[1] 陈光[1] 孙强金[1] 

机构地区：[1]南京理工大学金属纳米材料与技术联合实验室,江苏南京210094

出　　处：《稀土》2004年第5期51-57,共7页Chinese Rare Earths

基　　金：江苏省自然科学基金项目资助(BK2001053)

摘　　要：讨论了Mg-Cu-Y、Mg-Ni-Y和Mg-Zn-Y等三种重要的Mg-TM-Ln型的多组元Mg基纳米结构材料的成分构成、制备过程、微观结构和力学性能以及它们的形成机制。其中,制备方法涉及非晶部分晶化法、机械合金化/粉末冶金法(MA/PM法)和快速凝固(原子雾化)/粉末冶金法(RS/PM法)。结果表明,在Mg-Cu-Y系合金中,分布于非晶相基体之上的纳米晶体相使非晶合金的断裂应力增加。而不同成分的旋淬Mg-Cu-Y非晶条带弯曲断裂韧性的不同,很可能是由于存在于它们之中的纳米晶颗粒的性质有别而造成;在Mg-Ni-Y系合金中,Y部分地置换Ni将严重地影响其晶化行为,使得Mg-Ni-Y三元非晶合金中的纳米晶体相颗粒变得更加细小,而合金晶化行为的改变则导致了其杨氏模量的明显变化;在所有的金属合金中,RS/PMMg97Zn1Y2合金的比强度是最高的。而在所有的Mg基合金中,RS/PMMg-Zn-Y合金具有最佳的综合性能。Compositions, preparation methods,microstructures, mechanical properties and their forming mechanism of three kinds of Mg-based multi-components nanostructured alloys of Mg-TM-Ln type, including Mg-Cu-Y, Mg-Ni-Y and Mg-Zn-Y,were discussed in this paper.The preparation processes includes the method of crystallization based on amorphous, mechanical alloying/ powders metallurgy (MA/ PM) and rapid solidification (atomized powders) / powders metallurgy (RS/ PM).It is concluded that the nanocrystalline particles uniformly dispersed in the amorphous matrix can lead to a further increase in fracture stress in the alloy system of Mg-Cu-Y. The difference in the bending ductility of melt-spun ribbon of Mg-Cu-Y alloys may be attributed to the nature of the nanocrystalline particle in glassy matrix. A partial substitution of Ni by Y in the alloys of Mg-Ni-Y affects the crystallization behavior of amorphous phase seriously and results in finer microstructure, and then consequently the alteration of the crystallization behavior leads to the change of the Young's modulus of the alloys.The specific strength of RS/PM Mg_(97)Zn_1Y_2 is the highest among all metallic alloys and the RS/PM Mg-Zn-Y alloys have the best combination of tensile yield strength and plastic elongation among all kinds of Mg-based alloys.

关 键 词：Mg基纳米结构材料 时效脆性 热-电行为 杨氏模量 长周期六边形的结构 

分 类 号：TB383[一般工业技术—材料科学与工程]