喷射沉积含Nd镁合金挤压坯中第二相孪生与LPSO结构相形成  

Twinning of Second Phase and Formation of LPSO Structure in Extruded Billets of Nd-Contained Magnesium Alloy by Spray Deposition

作　　者：李振亮[1] 岳松波 刘飞[1] 李欣[1] 段宝玉[1] Li Zhenliang;Yue Songbo;Liu Fei;Li Xin;Duan Baoyu(Inner Mongolia University of Science&Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学

出　　处：《稀有金属材料与工程》2019年第11期3721-3726,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51364032);内蒙古自然科学基金项目(2018MS05039)

摘　　要：采用喷射沉积技术制备Mg-9Al-3Zn-1Mn-9Ca-1Nd合金沉积坯,对其进行挤压预变形(挤压温度为340℃,挤压比为25:1)。利用SEM、TEM和XRD研究镁合金第二相孪生、Mg-Nd-Zn型LPSO结构相的形成以及LPSO结构相与第二相孪生之间的关系。结果表明:在Al2(Ca,Nd)型C15相上形成了6H-LPSO结构相,C15粒子周围应力高度集中使分切应力提高且C15粒子周围形成的位错缠结区是C15粒子发生孪生的主要原因;纳米级C15粒子钉扎位错、抑制再结晶晶粒长大是(0002)基面织构及柱面(1010)和锥面(1011)织构形成的主要原因;当平均尺寸较小的纳米级C15粒子内Nd含量较高时C15粒子易形成LPSO结构相,而平均尺寸较大的微米级C15粒子内Nd含量较低时C15粒子易发生孪生。The deposited billets of Mg-9Al-3Zn-1Mn-9Ca-1Nd alloy were prepared by spray deposition technique and pre-deformed by extrusion(extrusion temperature 340℃,extrusion ratio 25:1).The formation of Mg-Nd-Zn type LPSO structure on the second phase of magnesium alloy and the relationship between the LPSO phase and the twinning of the second phase were studied by SEM,TEM and XRD.The results show that the 6H-LPSO structure phase is formed on the Al2(Ca,Nd)-type C15 phase.The formation of dislocation entanglement around the C15 particles and the high concentration of stress around C15 particles are the main cause of the twinning of the C15 particles.The nano-scale C15 particles,pinning dislocations and inhibition of recrystallization grain growth,are the main reasons for the formation of(0002)basal and prismatic(101-0)and pyramidal(101-1)textures.However,it is easy to form LPSO structure phase when the Nd content is higher in the smaller C15 particles,while the C15 particles are prone to twinning when the Nd content is lower in the micron-sized C15 particles with larger average size.

关 键 词：镁合金 C15粒子 LPSO 织构 第二相孪生 

分 类 号：TG146.22[一般工业技术—材料科学与工程]