Precipitation Behavior During Aging in α Phase Titanium Supersaturated with Cu
Precipitation Behavior During Aging in α Phase Titanium Supersaturated with Cu
复制标题
过饱和 Cu α 相钛时效过程中的析出行为
DOI：
10.1007/s11661-016-3344-7
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Mitsuhara;M.;Masuda;T.;Nishida;M.;Kunieda;T.;Fujii;H.
在1063 K（790 °C）下固溶处理之后，观察到Ti-2.3 mass pct Cu（Ti-2.3Cu）在673 K至873 K（400 °C至600 °C）下的时效硬化。研究了时效期间形成的析出物与硬度变化之间的关系。在673 K（400 °C）时效期间，硬度快速增加至200小时，随后缓慢增加至1000小时。在873 K（600 °C）时，硬度立即开始下降。透射电子显微镜观察表明，在α相中生长出直径为20 ~ 40 nm的细小盘状沉淀物。结果表明，这些析出相与位错相互作用，提高了硬度。在873 K（600 °C）下，观察到长度为1μm的沉淀物和长度为200 nm的Ti 2Cu颗粒。硬度的降低可能是由于沉淀物的形成降低了α相中Cu的浓度。在沉淀物的原子分辨率成像中观察到三个原子层的亮/暗对比度和hcp结构的小原子位移。这表明沉淀物不仅仅是Cu富集区，并且具有与Ti 2Cu相类似的周期性结构，Ti 2Cu相在这些时效温度下是热稳定的。
Age hardening of Ti-2.3 mass pct Cu (Ti-2.3Cu) at 673 K to 873 K (400 °C to 600 °C) after solution treatment at 1063 K (790 °C) was observed. The relationship between precipitates formed during aging and changes in hardness was investigated. During aging at 673 K (400 °C), the hardness increased rapidly up to 200 hours, and subsequently increased more slowly up to 1000 hours. At 873 K (600 °C), the hardness began to decrease immediately. Transmission electron microscopy showed that fine disk-shaped precipitates of 20 to 40 nm in diameter grew in theαphase. It is concluded that these precipitates interacted with dislocations and increased the hardness. At 873 K (600 °C), precipitates of 1µm in length and Ti2Cu particles of 200 nm in length were observed. The decrease in hardness may have resulted from the precipitate formation decreasing the concentration of Cu in theαphase. Bright/dark contrast of the three atomic layers and small atomic shift of the hcp structure were observed in the atomic resolution imaging of the precipitates. This suggests that the precipitates are not just Cu-enriched zones and have structures with similar periodicity to the Ti2Cu phase, which is thermally stable at those aging temperatures.