A New Polycrystalline Co-Ni Superalloy
A New Polycrystalline Co-Ni Superalloy
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DOI：
10.1007/s11837-014-1175-9
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发表时间：
2014-10
期刊：
影响因子：
2.6
通讯作者：
M. Knop;P. Mulvey;F. Ismail;A. Radecka;K. Rahman;T. C. Lindley;B. Shollock;M. Hardy;M. Moody;Tomas L Martin;P. Bagot;D. Dye
中科院分区：
文献类型：
--
作者：
M. Knop;P. Mulvey;F. Ismail;A. Radecka;K. Rahman;T. C. Lindley;B. Shollock;M. Hardy;M. Moody;Tomas L Martin;P. Bagot;D. Dye
2006年，人们发现了一种新有序的L12相Co3(Al,W)，它可以在面心立方(fcc) A1 Co基体中相干形成。从那时起，一个社区已经发展起来，试图将这些合金推向燃气轮机的实际应用。提出了一种新的候选多晶 Co-Niγ/γ′ 高温合金 V208C，其标称成分为 36Co-35Ni-15Cr-10Al-3W-1Ta (at.%)。该合金是通过传统的粉末冶金高温合金方法生产的。锻造后，获得约 56% 的 γ' 分数和 88 nm 的二次 γ' 尺寸，晶粒尺寸为 2.5μm。固溶线温度为1000℃。密度为 8.52 g cm−3，与具有该γ'水平的现有镍合金相似。该合金表现出流变应力异常，室温下的屈服强度为 920 MPa，800°C 下的屈服强度为 820 MPa，与 Mar-M247 相似。这些值明显高于迄今为止文献中提出的传统固溶和碳化物强化钴合金或γ/γ′钴高温合金的值。其抗氧化性在 800°C 下 100 h 的质量增加为 0.08 mg cm−2，也与现有高温镍高温合金相当。这些结果表明，钴基和钴镍高温合金在未来的燃气轮机应用中可能具有一定的前景。
In 2006, a new-ordered L12phase, Co3(Al,W), was discovered that can form coherently in a face-centered cubic (fcc) A1 Co matrix. Since then, a community has developed that is attempting to take these alloys forward into practical applications in gas turbines. A new candidate polycrystalline Co-Niγ/γ′ superalloy, V208C, is presented that has the nominal composition 36Co-35Ni-15Cr-10Al-3W-1Ta (at.%). The alloy was produced by conventional powder metallurgy superalloy methods. After forging, aγ′ fraction of ~56% and a secondaryγ′ size of 88 nm were obtained, with a grain size of 2.5μm. The solvus temperature was 1000°C. The density was found to be 8.52 g cm−3, which is similar to existing Ni alloys with this level ofγ′. The alloy showed the flow stress anomaly and a yield strength of 920 MPa at room temperature and 820 MPa at 800°C, similar to that of Mar-M247. These values are significantly higher than those found for either conventional solution and carbide-strengthened Co alloys or theγ/γ′ Co superalloys presented in the literature thus far. The oxidation resistance, with a mass gain of 0.08 mg cm−2in 100 h at 800°C, is also comparable with that of existing high-temperature Ni superalloys. These results suggest that Co-based and Co-Ni superalloys may hold some promise for the future in gas turbine applications.