At different annealing temperatures, the saturation magnetostrictions and the correlation between the permeability μi and the temperature T （μi-T curves） of the Co66Fe4Mo2Si16B12 alloy were investigated using a sm...At different annealing temperatures, the saturation magnetostrictions and the correlation between the permeability μi and the temperature T （μi-T curves） of the Co66Fe4Mo2Si16B12 alloy were investigated using a small-angle magnetization tester and core tester. The experimental results showed that the μi-T curves had different shapes at different ranges of annealing temperature; the permeability μi of the alloy improved with the increase of the annealing temperatures below 460℃; when the alloy was annealed above 480℃, the poor magnetic properties were considered to be caused by larger saturation magnetostriction.展开更多
The process of γ(fcc)→γ(fcc)+γ'(L12)phase transformation was simulated by using microscopic phase-field method for the low supersaturation NiAl9Fe6 alloy.It is found that in the γ' phase,the ordering degr...The process of γ(fcc)→γ(fcc)+γ'(L12)phase transformation was simulated by using microscopic phase-field method for the low supersaturation NiAl9Fe6 alloy.It is found that in the γ' phase,the ordering degree of Al atoms is obviously higher than that of Fe atoms,and the ordering of Al atoms precedes their clustering,while the case of Fe atoms is opposite.The α site is mainly occupied by Ni atoms,while the β site is occupied in common by Al,Fe and Ni atoms.At order-disorder interphase boundary,the ordering degree of Al atoms is higher than that of Fe atoms,and at the β site,the Fe atomic site occupation probabilities vary from high to low during ordering;the Al atomic site occupation probabilities are similar to those of Fe atoms,but their values are much higher than those of Fe atoms;Ni atoms are opposite to both of them.Meanwhile,during the ordering transformation,γ' phase is always a complex Ni3(AlFeNi)single-phase,and it is precipitated by the non-classical nucleation and growth style.Finally,in the alloy system,the volume of γ' ordered phase is less than that of γ phase,and the volume ratio of order to disorder is about 77%.展开更多
By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L...By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L12 Al3Ti-base intermetallic compound. The results are presented using the density of states (DOS) and one-electron properties, such as relative binding tendency between the atom and the model cluster, and hybrid bonding tendency between the alloying element and the host atoms. By comparing the four models of Ti4Al14X cluster, the effect of the Fe, Ni or Cu atom on the physical properties of Al3Ti-based L12 intermetallic compounds is analyzed. The results indicate that the addition of the Fe, Ni or Cu atom intensifies the relative binding tendency between Ti atom and Ti4Al14X cluster. It was found that the Fermi level (EF) lies in a maximum in the DOS for Ti4Al14Al cluster; on the contrary, the EF comes near a minimum tn the DOS for Ti4Al14X (X=Fe, Ni and Cu) cluster. Thus the L12 crystal structure for binary Al3Ti alloy is unstable, and the addition of the Fe, Ni or Cu atom to Al3Ti is benefical to stabilize L12 crystal structure. The calculation also shows that the Fe, Ni or Cu atom strengthens the hybrid bonding tendency between the central atom and the host atoms for Ti4Al14X cluster and thereby may lead to the constriction of the lattice of Al3Ti-base intermetallic compounds.展开更多
Cavitation erosion behavior of as-welded Cu12Mn8Al3Fe2Ni alloy in 3.5% NaCl aqueous solution was studied bymagnetostrictive vibratory device for cavitation erosion. The results show that the cavitation erosion resista...Cavitation erosion behavior of as-welded Cu12Mn8Al3Fe2Ni alloy in 3.5% NaCl aqueous solution was studied bymagnetostrictive vibratory device for cavitation erosion. The results show that the cavitation erosion resistance ofthe as-welded Cu12Mn8Al3Fe2Ni alloy is much more superior to that of the as-cast one. The cumulative mass lossand the mass loss rate of the as-welded Cu12Mn8Al3Fe2Ni alloy are almost 1/4 that of the as-cast one. SEM analysisof eroded specimens reveals that the as-cast Cu12Mn8Al3Fe2Ni alloy is attacked more severely than the as-weldedone. Microcracks causing cavitation damage initiate at the phase boundaries.展开更多
Influence of microstructure on electrochemical behavior of nanocrystalline Fe88Si12 alloy has been investigated in 3.5 wt% NaCl solution. The results show that FFe88Si12 alloy with optimal corrosion resistance is comp...Influence of microstructure on electrochemical behavior of nanocrystalline Fe88Si12 alloy has been investigated in 3.5 wt% NaCl solution. The results show that FFe88Si12 alloy with optimal corrosion resistance is composite of ordered Fe3Si and disordered Fe(Si) phases and grain size of 40 nm. Because the ordered Fe3Si structure is beneficial to form SiO2 film, which possesses good corrosion resistance compared with the Fe2O3 film from disordered Fe(Si). Moreover, although the decreased grain size is conducive to form preservative, as the grain size decreases to 10 nm, the grain boundary increases to above 30 vol%, which is the active sites for corrosion attack.展开更多
Cu-12% Fe （in weight） composite was prepared by casting, pretreating, and cold drawing. The microstructure was observed and Vickers hardness was measured for the composite at various drawing strains. Cu and Fe grain...Cu-12% Fe （in weight） composite was prepared by casting, pretreating, and cold drawing. The microstructure was observed and Vickers hardness was measured for the composite at various drawing strains. Cu and Fe grains could evolve into aligned filaments during the drawing process. X-ray diffraction （XRD） was used to analyze the orientation evolution during the drawing process. The axial direction of the filamentary structure has different preferred orientations from the radial directions. The strain of Fe grains linearly increases with an increase in the drawing strain up to 6.0, and deviates from the linear relation when the drawing strain is higher than 6.0. With an increase in the drawing strain, the microstructure scales of Fe filaments exponentially decrease. The density of the interface between Cu and Fe phases exponentially increases with an increase in the aspect ratio of Fe filaments. There is a similar Hall-Perch relationship between the hardness and Fe filament spacing. The refined microstructure from drawing deformation at drawing strains lower than 3.0 can induce a more significant hardening effect than that at drawing strains higher than 3.0.展开更多
This study describes the development of a one-pot strategy to produce spherical alloy microparticles for advanced near-net-shape manufacturing processes, including additive manufacturing and powder injection molding. ...This study describes the development of a one-pot strategy to produce spherical alloy microparticles for advanced near-net-shape manufacturing processes, including additive manufacturing and powder injection molding. The Al Si12 eutectic alloy(ca. 12 wt% Si) system was chosen as the model with which the main experiments were carried out. The proposed process synergistically integrates a few common,low-cost processing techniques including the mixing of Al micrometer size particles with silicon and sodium chloride, heat-treating the mixture at temperatures of 650–810°C, and the dissolution of salt in water to produce spherical Al Si12 alloy particles without the need to rely on costly melting and atomizing techniques. This new process can use laow-cost source Al and Si powders as the raw materials to produce10–200 um-sized spherical particles of Al Si12. The Ansys-CFX computational fluid dynamics software was used to analyze the flow behavior of Al Si12 liquid droplets and particle size refinement in the narrow voids of the sample.展开更多
文摘At different annealing temperatures, the saturation magnetostrictions and the correlation between the permeability μi and the temperature T （μi-T curves） of the Co66Fe4Mo2Si16B12 alloy were investigated using a small-angle magnetization tester and core tester. The experimental results showed that the μi-T curves had different shapes at different ranges of annealing temperature; the permeability μi of the alloy improved with the increase of the annealing temperatures below 460℃; when the alloy was annealed above 480℃, the poor magnetic properties were considered to be caused by larger saturation magnetostriction.
基金Project(50671084)supported by the National Natural Science Foundation of ChinaProject(Z200714)supported by Graduate Starting Seed Fund of Northwestern Polythechnical University,China
文摘The process of γ(fcc)→γ(fcc)+γ'(L12)phase transformation was simulated by using microscopic phase-field method for the low supersaturation NiAl9Fe6 alloy.It is found that in the γ' phase,the ordering degree of Al atoms is obviously higher than that of Fe atoms,and the ordering of Al atoms precedes their clustering,while the case of Fe atoms is opposite.The α site is mainly occupied by Ni atoms,while the β site is occupied in common by Al,Fe and Ni atoms.At order-disorder interphase boundary,the ordering degree of Al atoms is higher than that of Fe atoms,and at the β site,the Fe atomic site occupation probabilities vary from high to low during ordering;the Al atomic site occupation probabilities are similar to those of Fe atoms,but their values are much higher than those of Fe atoms;Ni atoms are opposite to both of them.Meanwhile,during the ordering transformation,γ' phase is always a complex Ni3(AlFeNi)single-phase,and it is precipitated by the non-classical nucleation and growth style.Finally,in the alloy system,the volume of γ' ordered phase is less than that of γ phase,and the volume ratio of order to disorder is about 77%.
文摘By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L12 Al3Ti-base intermetallic compound. The results are presented using the density of states (DOS) and one-electron properties, such as relative binding tendency between the atom and the model cluster, and hybrid bonding tendency between the alloying element and the host atoms. By comparing the four models of Ti4Al14X cluster, the effect of the Fe, Ni or Cu atom on the physical properties of Al3Ti-based L12 intermetallic compounds is analyzed. The results indicate that the addition of the Fe, Ni or Cu atom intensifies the relative binding tendency between Ti atom and Ti4Al14X cluster. It was found that the Fermi level (EF) lies in a maximum in the DOS for Ti4Al14Al cluster; on the contrary, the EF comes near a minimum tn the DOS for Ti4Al14X (X=Fe, Ni and Cu) cluster. Thus the L12 crystal structure for binary Al3Ti alloy is unstable, and the addition of the Fe, Ni or Cu atom to Al3Ti is benefical to stabilize L12 crystal structure. The calculation also shows that the Fe, Ni or Cu atom strengthens the hybrid bonding tendency between the central atom and the host atoms for Ti4Al14X cluster and thereby may lead to the constriction of the lattice of Al3Ti-base intermetallic compounds.
文摘Cavitation erosion behavior of as-welded Cu12Mn8Al3Fe2Ni alloy in 3.5% NaCl aqueous solution was studied bymagnetostrictive vibratory device for cavitation erosion. The results show that the cavitation erosion resistance ofthe as-welded Cu12Mn8Al3Fe2Ni alloy is much more superior to that of the as-cast one. The cumulative mass lossand the mass loss rate of the as-welded Cu12Mn8Al3Fe2Ni alloy are almost 1/4 that of the as-cast one. SEM analysisof eroded specimens reveals that the as-cast Cu12Mn8Al3Fe2Ni alloy is attacked more severely than the as-weldedone. Microcracks causing cavitation damage initiate at the phase boundaries.
文摘Influence of microstructure on electrochemical behavior of nanocrystalline Fe88Si12 alloy has been investigated in 3.5 wt% NaCl solution. The results show that FFe88Si12 alloy with optimal corrosion resistance is composite of ordered Fe3Si and disordered Fe(Si) phases and grain size of 40 nm. Because the ordered Fe3Si structure is beneficial to form SiO2 film, which possesses good corrosion resistance compared with the Fe2O3 film from disordered Fe(Si). Moreover, although the decreased grain size is conducive to form preservative, as the grain size decreases to 10 nm, the grain boundary increases to above 30 vol%, which is the active sites for corrosion attack.
基金Project supported by the National Natural Science Foundation of China （Nos. 11202183 and 50671092）, the National Science ＆ Tech- nology Pillar Program during the Eleventh Five-Year Plan Period （No. 2009BAG12A09）, the National High Technology Research and Development Program （863） of China （No. 2011AAllA101）, and the Zhejiang Provincial Natural Science Foundation of China （No. Y4100193）
文摘Cu-12% Fe （in weight） composite was prepared by casting, pretreating, and cold drawing. The microstructure was observed and Vickers hardness was measured for the composite at various drawing strains. Cu and Fe grains could evolve into aligned filaments during the drawing process. X-ray diffraction （XRD） was used to analyze the orientation evolution during the drawing process. The axial direction of the filamentary structure has different preferred orientations from the radial directions. The strain of Fe grains linearly increases with an increase in the drawing strain up to 6.0, and deviates from the linear relation when the drawing strain is higher than 6.0. With an increase in the drawing strain, the microstructure scales of Fe filaments exponentially decrease. The density of the interface between Cu and Fe phases exponentially increases with an increase in the aspect ratio of Fe filaments. There is a similar Hall-Perch relationship between the hardness and Fe filament spacing. The refined microstructure from drawing deformation at drawing strains lower than 3.0 can induce a more significant hardening effect than that at drawing strains higher than 3.0.
基金supported by the Technology Innovation Program(10063427,development of eco-friendly smelting technology for the production of rare metal production for lowering manufacturing costs using solid oxide membrane)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)the Competency Development Program for Industry Specialists of the Korean Ministry of Trade,Industry and Energy(MOTIE),operated by Korea Institute for Advancement of Technology(KIAT).(No.P0002019,HRD Program for High Value-Added Metallic Material Expert)supported by the Basic Research Laboratory Program through the Ministry of Education of the Republic of Korea(2019R1A4A1026125)。
文摘This study describes the development of a one-pot strategy to produce spherical alloy microparticles for advanced near-net-shape manufacturing processes, including additive manufacturing and powder injection molding. The Al Si12 eutectic alloy(ca. 12 wt% Si) system was chosen as the model with which the main experiments were carried out. The proposed process synergistically integrates a few common,low-cost processing techniques including the mixing of Al micrometer size particles with silicon and sodium chloride, heat-treating the mixture at temperatures of 650–810°C, and the dissolution of salt in water to produce spherical Al Si12 alloy particles without the need to rely on costly melting and atomizing techniques. This new process can use laow-cost source Al and Si powders as the raw materials to produce10–200 um-sized spherical particles of Al Si12. The Ansys-CFX computational fluid dynamics software was used to analyze the flow behavior of Al Si12 liquid droplets and particle size refinement in the narrow voids of the sample.
