Y对ZK60镁合金组织与性能的影响研究  

Effect of Y Concentration on the Microstructures and Mechanical Properties of ZK60 Alloys

作　　者：赵阔[1] 张莉[1] 孙扬善[1] 白晶[1] 

机构地区：[1]东南大学材料科学与工程学院江苏省先进金属材料高技术研究重点实验室,江苏南京211189

出　　处：《中国材料进展》2009年第7期72-77,共6页Materials China

基　　金：国家科技支撑计划(2006BAE04B07)资助

摘　　要：以ZK60为母合金,通过添加不同量的稀土元素Y,制备了2种Mg-Zn-Y-Zr合金。用扫描电镜和X射线衍射对合金铸态组织进行观测和分析发现,在ZK60合金中添加质量分数为1.04%的Y后,组织中析出I相(Mg3Zn6Y)。当Y的加入量增至2.10%,合金组织中主要析出W相(Mg3Zn3Y2)伴有微量的I相。I相和W相呈层片状分布在晶界处,有少量呈棒状,分布在晶内。这些细小、弥散分布的第二相对合金产生显著的强化作用,改善了合金的热加工性能,使得ZK60合金易热裂的缺点得到明显改善,在340～380℃温度范围内挤压没有发生热裂。实验表明,添加Y的挤压棒材的拉伸强度有较大幅度提高,延伸率略有增加。Based on wrought magnesium alloy ZK60, two alloys with different amount of Y addition have been prepared. Microstrncture observations reveal the existence of the ternary I phase distributing at grain boundaries and showing lamellar morphology. When yttrium addition increases to two percent, the microstructure of the alloy studied consists of the c^-Mg matrix and ternary phases of I and W. With the increase of yttrium addition, the temperature of ternary eutectic rises and the as-cast microstrncture is refined. Formation of tiny precipitates has been found during homogenizing treatment, which plays an important role in alloy strengthening. Investigations of extrusion indicate that no hot cracking occurs within the temperature range of 340 - 380℃ , yttrium addition improves the deformation ability of the alloy and thermal dynamic recrystallization occurs during hot extrusion in all the alloys studied.

关 键 词：镁合金 Mg—Zn-Y—Zr 添加元素 钇 热挤压 

分 类 号：TG146.22[一般工业技术—材料科学与工程]