Precipitates in biomedical Co-Cr-Mo-C-N-Si-Mn alloys
Precipitates in biomedical Co-Cr-Mo-C-N-Si-Mn alloys
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生物医学 Co-Cr-Mo-C-N-Si-Mn 合金中的析出物
DOI：
10.1007/s11661-011-1009-0
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
S.Mineta (Alfirano)
中科院分区：
文献类型：
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作者：
冨永雄一;久保健志;細矢憲,大塚浩二;S.Mineta (Alfirano)
研究了ASTM F 75/F 799 Co-28 Cr-6 Mo-0.25C-0.175N-（0 to 1）Si-（0 to 1）Mo（质量百分数）合金热处理前后的显微组织，特别注意了氮对相的影响和析出相的溶解。所采用的热处理温度和保持时间分别为1448至1548 K（1175至1275 °C）和0至43.2 ks。结果表明，添加Si和未添加Si的铸态合金中，分别出现了块状致密的π相沉淀和由M2 X型沉淀和γ相组成的片层状胞状团。氮的加入引起胞状沉淀，而硅的加入抑制了胞状沉淀并促进了π相的形成。透射电子显微镜（TEM）和扫描电子显微镜（SEM）分析表明，γ1→γ2+ M2 X可能是板层细胞集落形成的机制。氮在M2 X型、η相和π相沉淀物中富集，但被排除在M23 X6型沉淀物之外。根据合金组成的不同，在不同的热处理条件下，在所有的合金中观察到完全的沉淀溶解。氮的加入减少了在低的热处理温度下完全沉淀溶解所需的时间。在高温下，即，1548 K（1275 °C）时，沉淀物完全溶解被部分熔融所延迟，部分熔融伴随着沉淀物如π相的形成，导致完全和不完全沉淀物溶解区域之间的边界具有C-弯曲形状。
The microstructures of biomedical ASTM F 75/F 799 Co-28Cr-6Mo-0.25C-0.175N-(0 to 1)Si-(0 to 1)Mo alloys (mass pct) were investigated before and after heat treatment, with special attention paid to the effect of nitrogen on the phases and the dissolution of precipitates. The heat treatment temperatures and holding periods employed ranged from 1448 to 1548 K (1175 to 1275 °C) and 0 to 43.2 ks, respectively. A blocky-denseπ-phase precipitate and a lamellar cellular colony, which consisted of an M2X type precipitate and aγphase, were mainly detected in the as-cast alloys with and without added Si, respectively. The addition of nitrogen caused cellular precipitation, while the addition of Si suppressed it and enhanced the formation of theπphase. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses suggested that a discontinuous reaction,i.e.,γ1→γ2+ M2X, might be a possible formation mechanism for the lamellar cellular colony. Nitrogen was enriched in the M2X type,η-phase, andπ-phase precipitates, but was excluded from the M23X6type precipitate. Complete precipitate dissolution was observed in all of the alloys under varied heat treatment conditions depending on the alloy composition. The addition of nitrogen decreased the time required for complete precipitate dissolution at low heat-treatment temperatures. At high temperatures,i.e., 1548 K (1275 °C), complete precipitate dissolution was delayed by the partial melting that accompanied the formation of the precipitates such as theπphase resulting in the boundary between the complete and incomplete precipitate dissolution regions in having a C-curved shape.