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Microstructure of Bi-containing zirconium alloys

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Rare Metals 2022年第10期41卷 3566-3573页

作者： Han-Pei Zhao Mei-Yi Yao Jiao Huang Jin-Long Zhang Jian-Chao Peng Bang-Xin Zhou Laboratory for Microstructure Shanghai UniversityShanghai200444China Institute of Materials Shanghai UniversityShanghai200072China

The effect of Bi addition(0.05 wt%-0.50 wt%)on the microstructure of zirconium alloys,including T5(Zr-0.7 S n-1.0 Nb-0.3 Fe-0.1 Cr),S5(Zr-0.8 Sn-0.35 Nb-0.4 Fe-0.1 Cr),Zr-4(Zr-1.5 Sn-0.2 Fe-0.1 Cr) and Zr-1 Nb,was investigated by transmission electron microscopy(TEM),energy-dispersive spectroscopy(EDS) and selected area electron diffraction(SAED).Results show that with the increase in Bi content,h-Zr(Fe,Cr,Nb)2,o-Zr(Fe,Sn,Bi)_(2) and Zr-Fe-Cr-Nb-Sn-Bi second-phase particles(SPPs) precipitate successively in the T5+xBi and S5+xBi alloys;in the Zr-4+xBi alloys,h-Zr(Fe,Cr)2,o-Zr(Fe,Sn,Bi)2,Zr-Fe-Cr-Sn-Bi and Zr-Fe-Cr-Bi SPPs are detected successively.While as for Zr-1 Nb+xBi alloys,Bi-free SPPs appear.The addition of Bi promotes the precipitation of SPPs with Sn in the alloys.The concentration of Bi dissolved in α-Zr matrix increases with the decrease in Sn content in the alloys.Adding reasonable Bi has little influence on the solid solution content of Nb in α-Zr matrix.

关键词： Zirconium alloy Bismuth second-phase particles Microstructure

Anisotropy of mechanical properties of 2297-T87 Al–Li alloy thick plates

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2212-2223页

作者： Yuji Bai Zhixiu Wang Bo Jiang Mengqi Li Cong Zhu Xiaotong Gu Hai Li School of Materials Science and Engineering Changzhou UniversityChangzhou 213164China Jiangsu Key Laboratory of Material Surface Science and Technology Changzhou UniversityChangzhou 213164China

The tensile properties of 2297-T87 Al–Li alloy thick plates at different thickness position and in different direction were analyzed via tensile testing,optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),and transmission electron microscopy(TEM).Results indicated that the ultimate tensile strength(UTS)and yield strength(YS)of the alloy decreased firstly and then increased from the 1/8T position to the 1/2T position,whereas elongation to failure(Ef)decreased gradually such that its value along the rolling direction(RD)was higher than those along the transverse direction(TD)at the same thickness position.From the 1/8T position to the 3/8T position of the alloy,the UTS and YS along the TD were higher than those along the RD.At the 1/2T position of the alloy,the UTS,YS,and Ef along the RD were the highest,whereas those along the normal direction(ND)were the lowest.Microstructural observations further revealed that the anisotropy of tensile properties was related to grain morphology,crystal texture,second-phase particles,and Li atom segregation.

关键词： 2297 alloy thick plate tensile properties anisotropy grain morphology second-phase particles

phase transformation behavior of Ti_(49)Ni_(49.5)Fe_1V_(0.5) and Ti_(48)Ni_(48.5)Fe_1V_(2.5) alloys after different heat treatments

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Rare Metals 2014年第1期33卷 16-20页

作者： Yang-Yang Liu Fu-Shun Liu School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics

The effects of heat treatments on the phase transformation behavior of Ti49Ni49.5Fe1V0.5and Ti48Ni48.5Fe1V2.5 alloys were investigated. The results indicate that the alloys subjected to different heat treatments have B2 structure at room temperature. All the specimens exhibit a twostage B2 → R → B19r martensitic transformation on cooling, but a B19’ → B2 one-stage reverse martensitic transformation on heating except aged A1 alloy, which undergoes an abnormal two-stage transformation upon heating. The phase transformation temperatures are affected by heat treatments and V content, which can be attributed to the variation of the second-phase particles content in the matrix.

关键词： Keywords Heat treatments phase transformationbehavior Ti-Ni-Fe-V alloy second-phase particles

Microstructure and corrosion behavior of Zr–1.0Cr–0.4Fe–xMo alloys

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Rare Metals 2015年第2期34卷 118-124页

作者： Tian-Guo Wei Lu Zhang Zhi Miao Hong Liu Bai-Feng Luan Wen Wang Chong-Sheng Long Reactor Fuel and Materials Key Laboratory Nuclear Power Institute of China Nuclear and Radiation Safety Ministry of Environmental Protection Institute of Material Science and Technology Chongqing University

Possibility of using Mo as an alloying element in Zr-based alloys was attractive in terms of microstructure refinement and mechanical properties strengthening. In this research, Zr–1.0Cr–0.4Fe–xMo（0, 0.2, 0.4, and 0.6） alloys with different Mo contents were prepared by vacuum arcmelting method, the microstructure and the corrosion resistance of these alloys were investigated. Addition of Mo has a refinement effect on the microstructure; with the increase of Mo content, the a-laths in the as-cast samples and the grain size in the annealed samples decrease. Zr–1.0Cr–0.4Fe–xMo alloys have large numbers of fine second-phase particles（SPPs） in the matrix, the area fraction of the SPPs is more than 10 %. With the increase of Mo content, the population density of the SPPs increases significantly, while the average diameter of the SPPs decreases. Mo addition also affects the texture; the intensity of basal pole texture aligning normal direction decreases with the increase of Mo content in the alloys.Compared with Zr-4 and Zr–1Nb, Zr–1.0Cr–0.4Fe–xMo alloys have excellent corrosion resistance in 500 ℃/10.3 MPa steam. The corrosion rates of Mo-containing alloys are higher than that of Mo-free alloy, which is mainly attributed to the solute Mo atoms in the Zr matrix.Change of the SPPs features due to the increase of Mo content alleviates the degradation of corrosion resistance in some degree, but it is not the dominant factor.

关键词： Zr-based alloys Mo addition Microstructures second-phase particles Corrosion behavior

CONTINUUM VOID NUCLEATION MODEL FOR Al-Mg ALLOY SHEET BASED ON MEASURED PARTICLE DISTRIBUTION

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Acta Mechanica Solida Sinica 2009年第5期22卷 391-398页

作者： C.J.Butcher Department of Mechanical Engineering University of New BrunswickFrederictonNBCanadaE 3B 5A3

Void nucleation within measured particle fields of an aluminum alloy is investigated to develop a continuum nucleation model which reflects nucleation at the individual particle scale. A nucleation model for heterogeneous particle distributions is synchronized with the continuum model of Chu and Needleman using the average nucleation strain. The parameters in the continuum model are identified from the particle fields and are evaluated over the range of stress states observed in sheet metal forming. The synchronized continuum nucleation model achieves very good agreement with the nucleation trends for three measured particle fields in uniaxial tension, plane strain, and equal-biaxial tension.

关键词： void nucleation ductile fracture second-phase particles aluminum