Impacts of trace carbon on the microstructure of as-sintered biomedical Ti-15Mo alloy and reassessment of the maximum carbon limit.
Impacts of trace carbon on the microstructure of as-sintered biomedical Ti-15Mo alloy and reassessment of the maximum carbon limit.
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DOI：
10.1016/j.actbio.2013.10.034
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发表时间：
2014-02
影响因子：
9.7
通讯作者：
M. Yan;Ma Qian;Charlie Kong;M. Dargusch
中科院分区：
文献类型：
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作者：
M. Yan;Ma Qian;Charlie Kong;M. Dargusch
具有复杂三维形貌的晶界脆性碳化物的形成对生物医用钛合金的疲劳性能和耐腐蚀性都是不利的。对含碳量为0.032%的烧结态生物医用Ti-15Mo合金进行了详细的微观研究。在国标沿线观察到明显的富碳相，尽管碳含量远低于美国材料试验学会标准F2066规定的0.1%的最大碳限。透射电子显微镜分析表明，富碳相为面心立方Ti2C。三维层析重建显示，Ti2C结构具有与原始α-Ti相似的形貌。纳米压痕证实了GB Ti2C相的高硬度和高杨氏模数。为了避免在Ti-15Mo中形成GB碳化物，根据Thermo-Calc的预测，碳含量应控制在0.006%。对生物医用非合金钛、钛-6Al-4V和钛-16Nb中碳化物的形成也进行了类似的分析和表征。
The formation of grain boundary (GB) brittle carbides with a complex three-dimensional (3-D) morphology can be detrimental to both the fatigue properties and corrosion resistance of a biomedical titanium alloy. A detailed microscopic study has been performed on an as-sintered biomedical Ti–15Mo (in wt.%) alloy containing 0.032 wt.% C. A noticeable presence of a carbon-enriched phase has been observed along the GB, although the carbon content is well below the maximum carbon limit of 0.1 wt.% specified by ASTM Standard F2066. Transmission electron microscopy (TEM) identified that the carbon-enriched phase is face-centred cubic Ti2C. 3-D tomography reconstruction revealed that the Ti2C structure has morphology similar to primary α-Ti. Nanoindentation confirmed the high hardness and high Young’s modulus of the GB Ti2C phase. To avoid GB carbide formation in Ti–15Mo, the carbon content should be limited to 0.006 wt.% by Thermo-Calc predictions. Similar analyses and characterization of the carbide formation in biomedical unalloyed Ti, Ti–6Al–4V and Ti–16Nb have also been performed.