High-strength nanostructured Ti–12Mo alloy from ductile metastable beta state precursor
High-strength nanostructured Ti–12Mo alloy from ductile metastable beta state precursor
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DOI：
10.1016/j.msea.2010.03.044
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发表时间：
2010-06
期刊：
影响因子：
6.4
通讯作者：
F. Sun;F. Prima;T. Gloriant
中科院分区：
文献类型：
--
作者：
F. Sun;F. Prima;T. Gloriant
在这项研究中，通过冷坩埚悬浮熔炼（CCLM）方法合成了亚稳态β Ti-12Mo（wt.%）合金，然后在β域水中淬火。对淬火合金进行的拉伸试验显示出重要的延展性，达到断裂前伸长率的 45%。从淬火亚稳态β态开始，进行非等温电阻率和膨胀测量来检测相变，以控制纳米相沉淀序列。加热后，XRD 分析和 TEM 观察显示，β 基质中有非常精细的纳米级 omega 和 alpha 沉淀。拉伸测试结果表明，经过适当的热机械处理后，具有非常高的强化效果，在两步退火工艺后观察到这种效果尤其巨大，拉伸强度高达约1600MPa。这种高度增强的拉伸强度归因于通过 TEM 观察到的复杂晶粒内纳米结构，该结构由亚微米 β 晶粒内的两级 α 纳米沉淀物组成。
In this study, the metastable beta Ti–12Mo (wt.%) alloy was synthesized by the cold crucible levitation melting (CCLM) method and then quenched in water from the beta domain. The tensile test carried out on the as-quenched alloy showed an important ductility reaching 45% of elongation before fracture. From the as-quenched metastable beta state, non-isothermal electrical resistivity and dilatometry measurements were carried out to detect the phase transition in order to control the nanophase precipitation sequence. After heating, XRD analysis and TEM observations revealed a very fine nano-scale omega and alpha precipitation in the beta matrix. Tensile test results indicated a very high strengthening effect after appropriate thermo-mechanical treatments, which was observed particularly huge after a two-step annealing process where a tensile strength as high as around 1600MPa was obtained. This highly enhanced tensile strength was attributed to the complex intragranular nanostructure observed by TEM consisting of two-scale alpha nanoprecipitates inside sub-micrometer beta grains.