Effects of trace La additions on the microstructures and properties of nanoprecipitates strengthened Cu-Zr alloys
Effects of trace La additions on the microstructures and properties of nanoprecipitates strengthened Cu-Zr alloys
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微量La添加对纳米沉淀强化Cu-Zr合金组织与性能的影响
DOI：
10.1557/jmr.2014.382
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发表时间：
2015-01-28
影响因子：
2.7
通讯作者：
Chen, Zongning
中科院分区：
文献类型：
--
作者：
Wang, Tongmin;Li, Mingyu;Chen, Zongning
研究了微量La对Cu-0.2wt%Zr合金显微组织和力学性能的影响。对Cu-Zr合金进行了传统的热机械加工。采用等时时效和等温时效两种方法对时效工艺进行了优化。根据硬度和电导率测试结果，最佳时效工艺为85%冷轧后400 ℃等温150 min。如果铸态试样进行时效处理，La的加入明显细化了组织。然而，在冷轧后，La的加入对时效样品的晶粒尺寸没有显著影响。结合扫描电镜和透射电镜观察了析出相的分布和形貌，确定析出相为Cu 5 Zr。La的加入可同时提高铸态时效后试样的硬度和电导率，而冷轧态时效后试样的硬度和强度提高，电导率略有下降。XRD和TEM结果表明，La的加入提高了合金的晶格常数和位错密度。
The effects of trace La additions on the microstructures and mechanical properties of Cu-0.2 wt% Zr alloy have been investigated. Traditional thermo-mechanical processing was applied to the Cu-Zr alloys. Isochronal aging and isothermal aging were used to optimize the aging conditions. According to the hardness and conductivity tests, the optimized aging condition should be 150 min isothermal holding at 400 degrees C following 85% cold-rolling. If the as-cast sample is subjected to aging, the addition of La obviously refines the microstructures. After cold-rolling, however, the La addition has no significant effects on the grain size of the aged sample. SEM and TEM are combined to observe the distribution and morphology of the precipitates, which are identified to be Cu5Zr. The addition of La can improve the hardness and conductivity simultaneously in the as-cast samples after aging, while it improves the hardness and strength and decreases the conductivity slightly in the cold-rolled samples after aging. XRD and TEM results show that the lattice parameter and the dislocation density are increased by the addition of La.