Mechanism and mitigation of spontaneous Ga whisker growth on Cr_2GaC
Mechanism and mitigation of spontaneous Ga whisker growth on Cr_2GaC
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Cr_2GaC上Ga晶须自发生长的机理及抑制
DOI：
10.1007/s11431-018-9442-9
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Sun Zhengming
中科院分区：
文献类型：
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作者：
Zhang Peigen;Ding Jianxiang;Liu Yushuang;Yang Li;Tian Wubian;Ouyang Jian;Zhang Yamei;Sun Zhengming
在M_(n+1)AX_n(简称MAX)相材料上，A元素晶须的自发生长对其实际应用构成了障碍，因为它的稳定性受到了质疑。本文研究了在烧结的Cr2GaC样品上自发生长的Ga晶须。确定了自发生长的元素来源是Cr2GaC材料中的游离Ga，而不是Cr2GaC颗粒中的晶格原子，这消除了人们对Cr2GaC材料稳定性的怀疑。Ga晶须的生长行为和形貌遵循一个新的催化模型，该模型很好地解释和预测了晶须的生长行为。基于该模型的抑制策略原则上很简单：阻止或限制在Cr2GaC材料中的游离态Ga；避免了Cr2GaC颗粒的解理面，获得了高密度的Cr2GaC材料。
Spontaneous growth of A-element whiskers on M_(n+1)AX_n (MAX for short) phase materials poses a barrier to their practical applications,since it casts doubts on their stability.In this study,Ga whisker growth on sintered Cr_2GaC samples was investigated.The elemental source for spontaneous growth of Ga whiskers is identified as the free Ga contained in the Cr_2GaC material,not the lattice atoms from Cr_2GaC grains,which removes the doubts on the stability of Cr_2GaC material.The growth behavior and morphologies of the Ga whiskers follow a new catalysis-based model,with cleavage planes of Cr_2GaC grains involved as nucleation sites.This model explains and predicts well the growth behavior of the whiskers.The mitigation strategy based on this model is in principle simple:to prevent free Ga in Cr_2GaC material or limit it to a certain level;to avoid cleavage plane of Cr_2GaC grains;to achieve high density of the Cr_2GaC material.