摘要
采用自制热台建立了环形温度梯度场,利用丁二腈-水(SCN-H_(2)O)溶液开展了原位相分离观测实验,“模拟”了微重力条件下难混溶合金粉末中核/壳结构形貌的演化过程。结果表明:第二相(L_(2))微球在向试样中心迁移过程中尺寸不断变化。首先,初始L_(2)相在两相区内因碰撞而尺寸变大,但变化不明显;其次,部分L_(2)相在超过双节点温度位置进入单相区后,尺寸减小;最后,随着试样温度降低,L_(2)相因剧烈碰撞而尺寸急速增大,形成核结构。此外,核是由尺寸较大的L_(2)相微球经多次碰撞后在试样中心凝固而形成的。
An annular temperature gradient field was established by a self-made hot stage,and in-situ observation on the phase separation using SCN-H2O solution was performed to“simulate”the evolutionary procedure of the core/shell structure forming in immiscible alloy powders under microgravity conditions.The results show that the size of the second phase(L_(2))microspheres keeps changing during the migration to the specimen center.Firstly,the initial L_(2)phase becomes larger in the two-phase region due to collisions,but it is not obvious.Secondly,the size decreases after L_(2)phases exceed the binodal-temperature position and enter the single-phase region.Finally,with the decreasing temperature of specimen,the size of L_(2)phase increases rapidly due to fierce collisions and forms a core structure.In addition,the core structure is formed by the L_(2)phase microspheres experiencing multiple collisions in the center of the specimen.
作者
李梅
师晟祺
秦丽霞
彭银利
周先辉
LI Mei;SHI Shengqi;QIN Lixia;PENG Yinli;ZHOU Xianhui(School of Intelligent Manufacturing,Nanyang Institute of Technology,Nanyang 473004,China;Engineering Research Center of Additive Manufacturing Aeronautical Materials of Henan Province,Nanyang 473004,China)
出处
《粉末冶金工业》
CAS
北大核心
2023年第5期69-73,112,共6页
Powder Metallurgy Industry
基金
国家自然科学基金资助项目(52201044)
河南省自然科学基金资助项目(212300410213)
南阳市科技攻关资助项目(KJGG025)
河南省大学生创新创业训练计划资助项目(202211653009)。
关键词
核/壳结构
L_(2)
相分离
难混溶
原位观测
core/shell structure
L_(2)
phase separation
immiscible
in-situ observation
