Recent progress on research activities of phase diagrams in our laboratory has been presented. Experimental studies and thermodynamic calculations based on CALPHAD (Calculation of Phase Diagrams) method have been cond...Recent progress on research activities of phase diagrams in our laboratory has been presented. Experimental studies and thermodynamic calculations based on CALPHAD (Calculation of Phase Diagrams) method have been conducted in the following alloy systems.1.Database on microalloying steels including carbide, nitride and sulfide is now being constructed.2.ADAMIS (Alloy Database for Micro-Solders) containing 8 elements of Ag, Bi, Cu,In, Sb, Sn, Zn and Pb has been constructed, which can handle all combinations of these elements and all composition ranges.3.A thermodynamic database of Cu-base alloys including Cu-X binary system and Cu-Fe, Cu-Ni, Cu-Cr base ternary systems has been constructed.4.Experimental and thermodynamic calculations on Fe, Ni, Co and Ti aluminides have been conducted.5.Experimental and thermodynamic calculations on Co base magnetic recording media have been conducted.6.Thermodynamic analysis of interaction between magnetic and chemical orderings has been performed.By utilizing the information on phase diagrams, the following advanced materials have been developed. (A)New type of high speed steel with high hardness about Hv≈1000 by carbide dispersion carburizing method. (B)New Pb-free machinable stainless steel using titanium carbosulphide. (C)New Pb-free solder for Die-attaching use. (D)Shape memory alloys; Cu-base, Ferromagnetic Ni-base and Fe-base. (E)Invar alloys. (F)Egg-type powder.Typical examples of phase diagrams, phase stability, database and its application for the development of advanced materials will be presented.展开更多
A new two-step synthetic method was successfully developed to simplify the recrystallization process of lithium difluoro(oxalate)borate(LiODFB).Meanwhile,the purity of LiODFB as-prepared was determined by NMR,ICP-AES ...A new two-step synthetic method was successfully developed to simplify the recrystallization process of lithium difluoro(oxalate)borate(LiODFB).Meanwhile,the purity of LiODFB as-prepared was determined by NMR,ICP-AES and Karl Fisher measurements,respectively.The as-prepared LiODFB presents a high purity up to 99.95%.Its metal ions and water contents are under good control as well.Besides,its structure information and thermal properties were confirmed by FTIR,Raman and DSC-TGA analyses,respectively.LiODFB exerts fine thermostability and hypo-water-sensitivity and its structure information agrees well with previous literature.Furthermore,a combination of phase diagram and Raman spectroscopy were utilized to study the thermal phase behavior and ions coordination of LiODFB-DMC binary system to optimize the synthesis and recrystallization process.Although there are three types of molecular interaction forms(CIPs,AGG-IIa,AGG-IIIb)in LiODFB-DMC binary system,LiODFB can only be isolated as large single crystal solvate as LiODFB·(DMC)3/2 by slowly cooling subjected to the nucleation kinetics.Therefore,the fundamental information of our work is helpful in accelerating the application of LiODFB in Li-ion secondary batteries.展开更多
The room temperature phase diagram of Al-Zn-Cu system is the important basis for judging the phase constituents of the materials at the usage condition. New results about the room temperature phase diagram of the low ...The room temperature phase diagram of Al-Zn-Cu system is the important basis for judging the phase constituents of the materials at the usage condition. New results about the room temperature phase diagram of the low copper side in the Al-Zn-Cu systems have been shown in this study. Miscibility gap of fcc phase in the Al-Zn-Cu system has also been studied by experimental diffusion-couple method and thermodynamic calculation. Properties of this miscibility gap have been known. It is practically significant for the study on the aging behavior and for the control of the microstructure and properties of the Al alloys with Zn and Cu element.展开更多
The coarsening of particles dispersed in a solution was found by Ostwald in 1900. Then, the following cubic law between mean radius (r-) and annealing time (t) was established by Lifshitz-Slyozov and Wagner in 1961. I...The coarsening of particles dispersed in a solution was found by Ostwald in 1900. Then, the following cubic law between mean radius (r-) and annealing time (t) was established by Lifshitz-Slyozov and Wagner in 1961. It should be noted,however,that the above equation is valid in the coarsening of B particles in A-B solution.Therefore,some modification is necessary in the case of multi-component materials.For instance,the coarsening of (Fe,Cr)aCb in γFe-M-C matrix is described s folows;According to Eq.(2),the coarsening rate of M23C6 in heat-resistant steel(9%Cr^1%W-0.1%C)depends on the diffusion rate of Cr,because.However,experimental data inform us that the rate-de-termining element is not Cr but W as shown in Fig.1The problem is solved by modifing the formula of M23C6 from (Fe,Cr,W)23C6to Fe4(Cr,W)19C6 in this case (Fig.2).Consequently,the coarsening equation is expressed as follows.展开更多
文摘Recent progress on research activities of phase diagrams in our laboratory has been presented. Experimental studies and thermodynamic calculations based on CALPHAD (Calculation of Phase Diagrams) method have been conducted in the following alloy systems.1.Database on microalloying steels including carbide, nitride and sulfide is now being constructed.2.ADAMIS (Alloy Database for Micro-Solders) containing 8 elements of Ag, Bi, Cu,In, Sb, Sn, Zn and Pb has been constructed, which can handle all combinations of these elements and all composition ranges.3.A thermodynamic database of Cu-base alloys including Cu-X binary system and Cu-Fe, Cu-Ni, Cu-Cr base ternary systems has been constructed.4.Experimental and thermodynamic calculations on Fe, Ni, Co and Ti aluminides have been conducted.5.Experimental and thermodynamic calculations on Co base magnetic recording media have been conducted.6.Thermodynamic analysis of interaction between magnetic and chemical orderings has been performed.By utilizing the information on phase diagrams, the following advanced materials have been developed. (A)New type of high speed steel with high hardness about Hv≈1000 by carbide dispersion carburizing method. (B)New Pb-free machinable stainless steel using titanium carbosulphide. (C)New Pb-free solder for Die-attaching use. (D)Shape memory alloys; Cu-base, Ferromagnetic Ni-base and Fe-base. (E)Invar alloys. (F)Egg-type powder.Typical examples of phase diagrams, phase stability, database and its application for the development of advanced materials will be presented.
基金Project(51371198)supported by the National Natural Science Foundation of ChinaProject(K1202039-11)supported by the Science and Technology Project of Changsha,China
文摘A new two-step synthetic method was successfully developed to simplify the recrystallization process of lithium difluoro(oxalate)borate(LiODFB).Meanwhile,the purity of LiODFB as-prepared was determined by NMR,ICP-AES and Karl Fisher measurements,respectively.The as-prepared LiODFB presents a high purity up to 99.95%.Its metal ions and water contents are under good control as well.Besides,its structure information and thermal properties were confirmed by FTIR,Raman and DSC-TGA analyses,respectively.LiODFB exerts fine thermostability and hypo-water-sensitivity and its structure information agrees well with previous literature.Furthermore,a combination of phase diagram and Raman spectroscopy were utilized to study the thermal phase behavior and ions coordination of LiODFB-DMC binary system to optimize the synthesis and recrystallization process.Although there are three types of molecular interaction forms(CIPs,AGG-IIa,AGG-IIIb)in LiODFB-DMC binary system,LiODFB can only be isolated as large single crystal solvate as LiODFB·(DMC)3/2 by slowly cooling subjected to the nucleation kinetics.Therefore,the fundamental information of our work is helpful in accelerating the application of LiODFB in Li-ion secondary batteries.
文摘The room temperature phase diagram of Al-Zn-Cu system is the important basis for judging the phase constituents of the materials at the usage condition. New results about the room temperature phase diagram of the low copper side in the Al-Zn-Cu systems have been shown in this study. Miscibility gap of fcc phase in the Al-Zn-Cu system has also been studied by experimental diffusion-couple method and thermodynamic calculation. Properties of this miscibility gap have been known. It is practically significant for the study on the aging behavior and for the control of the microstructure and properties of the Al alloys with Zn and Cu element.
文摘The coarsening of particles dispersed in a solution was found by Ostwald in 1900. Then, the following cubic law between mean radius (r-) and annealing time (t) was established by Lifshitz-Slyozov and Wagner in 1961. It should be noted,however,that the above equation is valid in the coarsening of B particles in A-B solution.Therefore,some modification is necessary in the case of multi-component materials.For instance,the coarsening of (Fe,Cr)aCb in γFe-M-C matrix is described s folows;According to Eq.(2),the coarsening rate of M23C6 in heat-resistant steel(9%Cr^1%W-0.1%C)depends on the diffusion rate of Cr,because.However,experimental data inform us that the rate-de-termining element is not Cr but W as shown in Fig.1The problem is solved by modifing the formula of M23C6 from (Fe,Cr,W)23C6to Fe4(Cr,W)19C6 in this case (Fig.2).Consequently,the coarsening equation is expressed as follows.
