Strengthening effects and thermal stability of the ultrafine grained microstructure of a nickel base superalloy at room and elevated temperatures
Strengthening effects and thermal stability of the ultrafine grained microstructure of a nickel base superalloy at room and elevated temperatures
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镍基高温合金超细晶组织的室温和高温强化效果和热稳定性
DOI：
10.1016/j.matchar.2018.08.055
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发表时间：
2018-11
影响因子：
4.7
通讯作者：
Lavernia Enrique J
中科院分区：
文献类型：
--
作者：
Xia Tian;Xie Yuehuang;Yang Chao;Zeng Wei;Bi Zhongnan;Liang Jiamiao;Zhu Guoliang;Wang Jun;Zhang Deliang;Lavernia Enrique J
一种掺5 vol的超细晶镍基高温合金。% y2o3纳米颗粒，Alloy 718-5 vol。采用高能机械铣削718合金加工切屑、火花等离子烧结、热挤压和热处理相结合的粉末冶金工艺制备了%Y2O3合金，研究了其在室温和650 ℃下的显微组织和力学性能。研究表明，y2o3纳米颗粒与基体Al发生反应，形成y4al2o9纳米颗粒（平均直径12.5 nm），在970 ℃（0.78Tm， K中合金的固相温度）下热处理稳定。由于y4al2o9纳米颗粒具有较高的热稳定性和有效的钉住晶界，合金的UFG显微组织（平均晶粒尺寸为179 nm）在热处理过程中保持稳定。晶粒边界和纳米颗粒强化使热处理后的718-5合金 vol。% y2o3合金具有显著的室温抗拉屈服强度1870 MPa。结果表明，在650 °C时，UFG显微组织的晶界强化效应仍然显著，但与室温相比明显减弱。在650 ℃时，尽管UFG显微组织中不存在γ′和γ″相，但晶界强化和纳米颗粒强化效应可能与测试温度无关，并保持了800 MPa的较高抗拉屈服强度。
An ultrafine grained (UFG) nickel base superalloy doped with 5 vol.%Y2O3nanoparticles, Alloy 718-5 vol.%Y2O3, was fabricated by a powder metallurgy route which combines high energy mechanical milling of Alloy 718 machining chips, spark plasma sintering, hot extrusion and heat treatment, and its microstructure and mechanical properties at room temperature and 650 °C were studied. The study showed that the Y2O3nanoparticles reacted with Al from the base alloy and transformed to Y4Al2O9nanoparticles (average diameter: 12.5 nm) which were stable during heat treatment at 970 °C (0.78Tm, whereTmis the solidus temperature of the alloy in K). As a result of the high thermal stability of Y4Al2O9nanoparticles and their effective pinning of the grain boundaries, the UFG microstructure (average grain size: 179 nm) of the alloy was stable during heat treatment. Grain boundary and nanoparticle strengthening rendered the heat treated Alloy 718-5 vol.%Y2O3alloy with a notable room temperature tensile yield strength of 1870 MPa. It was demonstrated that the grain boundary strengthening effect associated with the UFG microstructure was still significant at 650 °C, but clearly decreased from its level at room temperature. The grain boundary strengthening and nanoparticle strengthening effects which are likely to be independent of test temperature sustain a reasonably high tensile yield strength of 800 MPa at 650 °C, despite the absence of γ′ and γ″ precipitates in the UFG microstructure.
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DOI：
10.1016/0001-6160(89)90053-9
发表时间：
1989-09
期刊：
Acta Metallurgica
影响因子：
--
作者：
G. Schaffer;M. Loretto;R. Smallman;J. Brooks
通讯作者：
G. Schaffer;M. Loretto;R. Smallman;J. Brooks
DOI：
10.1007/s11661-006-1041-7
发表时间：
2006-12
期刊：
Metallurgical and Materials Transactions A
影响因子：
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作者：
D. Srinivasan;P. R. Subramanian
通讯作者：
D. Srinivasan;P. R. Subramanian
影响因子：
4.7
作者：
Azadian, S;Wei, LY;Warren, R
通讯作者：
Warren, R
DOI：
10.1016/j.msea.2008.02.056
发表时间：
2009-03
影响因子：
6.4
作者：
C. Saldana;Pin Yang;J. Mann;W. Moscoso;D. D. Gill-D.;S. Chandrasekar;K. Trumble
通讯作者：
C. Saldana;Pin Yang;J. Mann;W. Moscoso;D. D. Gill-D.;S. Chandrasekar;K. Trumble
DOI：
10.4028/www.scientific.net/msf.638-642.2363
发表时间：
2010-01
期刊：
Materials Science Forum
影响因子：
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作者：
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通讯作者：
X. Xie;S. Fu;Shuangqun Zhao;J. Dong