Age-hardening behavior of a single-crystal Cu-Ti alloy
Age-hardening behavior of a single-crystal Cu-Ti alloy
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单晶铜钛合金的时效硬化行为
DOI：
10.1016/j.matlet.2014.05.128
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
A. Iwase
中科院分区：
文献类型：
--
作者：
S. Semboshi;E. Hinamoto;A. Iwase
研究了723 K时效Cu-4 mol% Ti单晶合金的显微组织和硬度，并与常规多晶试样进行了比较。由于缺乏晶界，只有亚稳的β′-Cu4Ti析出物在晶粒中分散得很好，并在晶粒中连续生长，而没有像多晶样品那样不连续地转变为稳定的β-Cu4Ti层合物。硬度随时效增加而增大，在约12 h时达到最大值，这是由于β′-Cu4Ti的精细分散所致。在进一步时效过程中，单晶试样的硬度比多晶试样的硬度下降更缓慢。单晶试样的硬度逐渐降低是由于β′-Cu4Ti的逐渐生长。相反，多晶试样硬度的快速下降是由于粗β-Cu4Ti的不连续形成，伴随着细β ' -Cu4Ti析出的消耗。
The microstructure and hardness of a single-crystal Cu-4 mol% Ti alloy aged at 723 K are studied, and compared with those for conventional poly-crystal specimens. Only the metastable β′-Cu4Ti precipitates are dispersed finely and grown continuously in grains without discontinuous transformation into the stable β-Cu4Ti laminates as found in poly-crystal specimens, because of lack of grain boundaries. Hardness increases with aging and reaches a maximum at approximately 12 h, which is attributed to the fine dispersion of β′-Cu4Ti. On further aging, hardness decreases more gradually in single-crystal specimens than in poly-crystal specimens. The gradual decrease in hardness for single-crystal specimens is due to the gradual growth of β′-Cu4Ti. Conversely, the rapid decrease in the hardness of poly-crystal specimens is due to the discontinuous formation of coarse β-Cu4Ti, that accompanies the consumption of fine β′-Cu4Ti precipitates.