快速凝固Mg-6Zn-5Ce合金的微观组织研究

摘要

The atomization-twin rolls quenching technology has been utilized to successfully prepare the rapidly solidified Mg-6Zn-5Ce alloys in the form of flakes. The microstructures, phase compositions and thermal stability ot the rapidly solidified alloy have been investigated by TEM, XRD and DSC, respectively. The results indicate that the alloy is characteristic of fine microstructures and the grain size is about 5μm. Moreover, a large number of dispersed precipitates are mostly near spherical in shape. Through the EDS analysis, the precipitates are MgxZnyCez phases (atomic ratio of Zn/Ce is 2: 1) with high melting points.%采用雾化-双辊急冷法成功地制备了快速凝固Mg-6Zn-5Ce(质量分数,下同)合金薄片,并利用透射电子显微镜、X射线衍射仪和差示扫描分析仪对其微观组织、物相种类和热稳定性进行了研究.研究发现,快速凝固Mg-6Zn5-5Ce合金的组织细小,晶粒尺寸约为5μm.合金中均匀分布着细小、弥散的第二相颗粒,经分析可知,这种以球状为主的颗粒为高熔点的MgxZnyCez三元相,其Zn/Ce原子比约为2∶1.