重力对Sn-20%Ni合金的初生相形态和包晶反应的影响  

Effect of Gravity on Primary Phase Morphology and Peritectic Reaction of Sn-20% Ni Alloy

作　　者：张佳俊 罗兴宏[1,2] 孔亚非 张桂圆 李洋 ZHANG Jiajun;LUO Xinghong;KONG Yafei;ZHANG Guiyuan;LI Yang(Shi-Changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China)

机构地区：[1]中国科学院金属研究所师昌绪先进材料创新中心,沈阳110016 [2]中国科学技术大学材料科学与工程学院,沈阳110016

出　　处：《材料研究学报》2023年第2期111-119,共9页Chinese Journal of Materials Research

基　　金：载人空间站工程项目。

摘　　要：使用高度为50 m的落管研究了Sn-20%(质量分数) Ni包晶合金在重力和微重力作用下的凝固行为。用金相显微镜(OM)观察了合金的凝固组织并使用图像处理软件IPP(Image Pro Plus)统计了样品中的初生相、包晶相以及终凝相的含量,使用能谱仪(EDS)和X射线衍射(XRD)仪分析了样品凝固组织中的成分分布和组成相。结果表明,Sn-20%Ni包晶合金的凝固以初生相在固液界面前沿形核、枝晶生长和包晶反应的形式进行,重力对初生相的生成和包晶反应都有显著的影响,在微重力作用下的微观组织配比、分布以及合金元素的分布都与在重力作用下明显不同。在重力的作用下残余初生相的含量和残余初生相和包晶相的总量总是比在重力作用下的低,而包晶相的含量则总是比在微重力作用下的高。同时,样品中溶质元素的分布与残余初生相和包晶相的总量的分布趋势基本一致。结果表明,微重力环境有利于Sn-20%Ni合金初生相的形核和长大,而重力环境则促进包晶反应,其原因与重力导致的浮力对流和晶核沉积有关。The solidification behavior of a Sn-20%(mass fraction) Ni peritectic alloy in conditions of ordinary gravity and microgravity were comparatively studied by using a 50-meter-high drop tube. The solidified microstructure of the alloy was observed by optical metalloscopy(OM), the percentages of residual primary phase, peritectic phase and final solidification phase in the samples were counted by IPP(Image Pro Plus) software, and the solute distribution and phase composition in the samples were determined by means of energy dispersive spectrometer(EDS) and X-ray diffractometer(XRD). The results show that the solidification process of Sn-20% Ni may involve the primary phase nucleation at solid-liquid interface front, dendrite growth and peritectic reaction. Gravity has significant effect on both the primary phase formation and peritectic reaction, resulting in significant difference in the partition and distribution of phases as well as the distribution of alloying elements obtained in the conditions of microgravity and ordinary gravity respectively. The amount of residual primary phase and the total amount of residual primary phase plus peritectic phase in ordinary gravity condition is always lower than those in microgravity condition, while the quantity of peritectic phase is always higher. In addition, the distribution of solute element in the samples are basically consistent with those of the total amount of residual primary phase plus peritectic phase. These results indicate that the microgravity environment is favorable to the formation and growth of primary phase of the Sn-20% Ni alloy, in the contrary, the gravity environment promotes peritectic reaction, which is related to buoyancy convection and crystal nucleus deposition induced by gravity.

关 键 词：金属材料 Sn-Ni合金 包晶反应 落管 微重力 凝固 

分 类 号：TG146.1[一般工业技术—材料科学与工程]