Enhanced superplasticity for (α + β)-hot rolled Ti–6Al–4V–0.1B alloy by means of dynamic globularization
Enhanced superplasticity for (α + β)-hot rolled Ti–6Al–4V–0.1B alloy by means of dynamic globularization
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DOI：
10.1016/j.matdes.2014.01.033
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发表时间：
2014-06
影响因子：
8.4
通讯作者：
Shibayan Roy;S. Suwas
中科院分区：
文献类型：
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作者：
Shibayan Roy;S. Suwas
摘要：热机械加工的 Ti-6Al-4V 合金，添加（0.1 wt.%）且不添加硼，在超塑性变形条件（温度，T= 850° C，初始应变速率，ε ̇= 3× 10-4 s− 1）下进行了拉伸试验。与不含硼的基础合金（~ 365%）相比，添加硼的合金表现出更高的延伸率（~ 430%）。添加硼合金的优异延展性归因于增强的 α/β 界面边界滑动。这是由于剧烈的动态球化导致变形微观结构中大量存在尺寸细化且分布狭窄的等轴初生 α 晶粒。变形过程中，TiB 颗粒周围确实会出现空腔；然而，这些空洞是极其局部的，不会引起宏观裂纹。
Abstract Thermo-mechanically processed Ti–6Al–4V alloy, with (0.1 wt.%) and without boron addition, has been subjected to tensile test under superplastic deformation conditions (Temperature, T= 850° C and initial strain rate, ε ̇= 3× 10-4 s− 1). The boron added alloy exhibited higher elongation (∼ 430%) in comparison to the base alloy without boron (∼ 365%). Superior ductility of the boron added alloy has been attributed to an enhanced α/β interfacial boundary sliding. This was caused by riotous dynamic globularization leading to the abundant presence of equiaxed primary α grains with refined sizes and narrow distribution in the deforming microstructure. Cavities do occur around TiB particles during deformation; the cavities are, however, extremely localized and do not cause macroscopic cracking.