Mechanical properties of U-0.95 mass fraction of Ti alloy quenching and aging treatment: a first principles study

Springer Science and Business Media LLC - Tập 3 - Trang 244-251 - 2014
Jian-Bo Qi1,2, Guang-Xin Wu1, Jie-Yu Zhang1
1School of Materials Science and Engineering, Shanghai University, Shanghai, People’s Republic of China
2China North Nuclear Fuel Co. Ltd., Baotou, People’s Republic of China

Tóm tắt

First principles plane wave pseudopotential method was executed to calculate the mechanical properties with respect to the uranium-0.95 mass fraction of titanium (U-0.95 mass fraction of Ti) alloy for quenching and aging, including the elastic modulus, the value of shear modulus to bulk modulus (G/B) and the ideal tensile strength. The further research has also been done about the crack mechanism through Griffith rupture energy. These results show that the elastic moduli are 195.1 GPa for quenching orthorhombic α´ phase and 201.8 GPa for aging formed Guinier-Preston (G.P) zones, while G/B values are 0.67 and 0.56, respectively. With the phase change of uranium-titanium (U-Ti) alloy via the quenching treatment, the ideal tensile strength is diverse and distinct with different crystal orientations of the anisotropic α´ phase. Comparison of quenching and short time aging treatment, both of the strength and toughness trend to improve slightly. Further analysis about electronic density of states (DOS) in the electronic scale indicates that the strength increases continuously while toughness decreases with the aging proceeding. The equilibrium structure appears in overaging process, as a result of decomposition of metastable quenching α´ phase. Thereby the strength and toughness trend to decrease slightly. Finally, the ideal fracture energies of G.P zones and overaging structure are obtained within the framework of Griffith fracture theory, which are 4.67 J/m2 and 3.83 J/m2, respectively. These results theoretically demonstrate strengthening effect of quenching and aging heat treatment on U-Ti alloy.

Tài liệu tham khảo

Baschwitz R, Colombie M, Foure M (1968) Etude du revenue des phases orthorhombiques metastables d’all-iages uranium-titane tetrant 4, 8 et 9, 5 at% de titane. J Nucl Mater 28:246–256 Federer JI (1969) Effect of alloy additions and heat treatments on the mechanical properties of U-0.5Ti alloy. U. S. Atomic Energy Commission Contract Report, Tenn, Report No. ORNL-TM-2482 Harding AG, Waldron MB (1958) Transformation in uranium alloys with high solute solubility in the B. C. C. gamma phase, part I. Preliminary observations on the “banded structure” produced by non equilibrium transformations in uranium alloys. Atomic Energy Research Establishment, Harwell, Report No. AERE-M/R-2673 Anagnostides M, Colombie M, Monti H (1964) Metastable phase in the alloys uranium-niobium. J Nucl Mater 11:67–76 Douglass DL (1961) The structure and mechanical properties of uranium-titanium martensites. Trans ASM 53:307–319 Anagnostidis M, Baschwitz R, Colombie M (1966) Phase metastables dans les alliages uranium-titane. Mem Sci Rev Met 63:163–168 Speer JG, Edmonds DV (1999) Aging of α ’a martensite in U-0.77Ti. Acta Mater 47(7):2197–2205 Yakel HL (1969) A Fortran-language program for plotting stereographic projections of lattice plane normals and directions. U. S. Atomic Energy Commission Contract Report, Tenn, Report No. W-7405-ENG-26 Hatt BA, Roberts JA (1960) The ω-phase in zirconium base alloys. Acta Mater 8:575–584 Hatt BA (1966) The orientation relationship between the gamma and alpha structures in uranium-zirconium alloys. J Nucl Mater 19:133–141 Stelly M (1972) Precipitation isotherme dans des alliages d’uranium-cinetique de precipitation. Commissariat a l’Energie, Atomique, Centre d’Etudes Nucleaires, Saclay, Report No. CEA-R-4326 Skriver HL, Andersen OK, Johansson B (1978) Calculated bulk properties of the actinide metals. Phys Rev Lett 41:42–45 Wills JM, Eriksson O (1992) Crystal structure stabilities and electronic structure for the light actinides Th, Pa and U. Phys Rev B 45:13879–13890 Söderlind P, Eriksson O, Johansson B et al (1994) Electronic properties of f-electron metals using the generalized gradient approximation. Phys Rev B 50:7291–7294 Söderlind P (2002) First-principles elastic and structural properties of uranium metal. Phys Rev B 66:085113 Hohenberg PC, Kohn W (1964) Inhomogeneous electron gas. Phys Rev 136:B864–B871 Kohn W, Sham LJ (1965) Self-consistent equations including exchange and correlation effects. Phys Rev 140:A1133–A1138 Kresse G, Furthmuller J (1996) Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys Rev B 54(16):11169–11186 Perdew JP, Burke K, Ernzerhof M (1996) Generalized gradient approximation made simple. Phys Rev Lett 77:3865–3868 Vanderbilt D (1990) Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Phys Rev B 41:7892–7895 Hill R (1952) The elastic behaviour of a crystalline aggregate. Proc Phys Soc 65:349–354 Monkhorst HJ, Pack JD (1976) Special points for Brillouin-zone integrations. Phys Rev B 13:5188–5192 Krenn CR, Roundy D, Morris JW (2001) Ideal strengths of bcc metals. Mater Sci Eng A 319–321:111–114 Clatterbuck DM, Chrzan DC, Morris JW (2003) The ideal strength of iron in tension and shear. Acta Mater 51:2271–2283 Chatterjee A, Niwa S, Mizukami F (2005) Structure and property correlation for Ag deposition on α-Al2O3: a first principle study. J Mol Graphics Model 23:447–456 Gong HR (2009) Electronic structure and related properties of Pd/TiAl membranes. Intermetallics 17:562–567