Interactions of solute atoms in biodegradable zinc alloys and their effect on alloy mechanical properties have been less investigated.In this work,the interactions between the common solutes(Li,Mg,Mn,Cu,and Ag)used in...Interactions of solute atoms in biodegradable zinc alloys and their effect on alloy mechanical properties have been less investigated.In this work,the interactions between the common solutes(Li,Mg,Mn,Cu,and Ag)used in the biodegradable Zn alloys,including a solute-solute pair with the same element or with two different elements,are investigated based on first-principles calculations.It is found that the energetically favorable configuration is the third nearest-neighboring for most solute-solute pairs in the bulk lattice because of the relatively strong electronic interaction between solute and Zn atoms or the relatively small local elastic deformation associated with the configuration.Considering that interfacial cleavage is a key fracture mode of zinc,the segregation ability of these solutes and their effect on the{1012}twin boundary cohesion are also examined.The result shows that Li tends to fully occupy its preferred site in the twin boundary,while Mg,Mn,Cu,or Ag has a concentration limitation in the twin boundary.The twin boundary cohesion can be significantly enhanced by the segregation of Mn,followed by Cu and Ag,because of the contribution of their d states close to the Fermi level.Furthermore,the co-segregation ability of two solute atoms in the twin boundary increases with increasing the binding tendency of these two solute atoms in the boundary.Mn and Li or Mg show a relatively strong co-segregation ability in the twin boundary.Adding Mn to Zn-Li or Zn-Mg alloys can significantly enhance the resistance to fracture of twin boundaries.展开更多
The enthalpies of mixing of L-arginine with 2,2,2-trifluoroethanol and their respective enthalpies of dilu- tion in aqueous solutions at 298.15, 303.15 and 310.15 K were determined as a function of the mole fraction b...The enthalpies of mixing of L-arginine with 2,2,2-trifluoroethanol and their respective enthalpies of dilu- tion in aqueous solutions at 298.15, 303.15 and 310.15 K were determined as a function of the mole fraction by flow microcalorimetric measurement. These experimental results were analyzed to obtain heterotactic enthalpic interaction coeffieients（hxy , hxy , hxy） according to the McMillan-Mayer theory. The hxy coefficients between L-arginine molecule studied and 2,2,2-trifluoroethanol molecule in aqueous solutions at 298.15, 303.15 and 310.15 K were found to be all negative. The results were discussed in terms of solute-solute interaction and solute-solvent interaction.展开更多
基金The authors acknowledge the financial support from the Australian Research Council(No.DP190102373)This work was supported by computational resources provided by the Australian Gov-ernment through National Computational Infrastructure(Raijin)and Pawsey supercomputing centre(Magnus)under the National Computational Merit Allocation Scheme(NCMAS).
文摘Interactions of solute atoms in biodegradable zinc alloys and their effect on alloy mechanical properties have been less investigated.In this work,the interactions between the common solutes(Li,Mg,Mn,Cu,and Ag)used in the biodegradable Zn alloys,including a solute-solute pair with the same element or with two different elements,are investigated based on first-principles calculations.It is found that the energetically favorable configuration is the third nearest-neighboring for most solute-solute pairs in the bulk lattice because of the relatively strong electronic interaction between solute and Zn atoms or the relatively small local elastic deformation associated with the configuration.Considering that interfacial cleavage is a key fracture mode of zinc,the segregation ability of these solutes and their effect on the{1012}twin boundary cohesion are also examined.The result shows that Li tends to fully occupy its preferred site in the twin boundary,while Mg,Mn,Cu,or Ag has a concentration limitation in the twin boundary.The twin boundary cohesion can be significantly enhanced by the segregation of Mn,followed by Cu and Ag,because of the contribution of their d states close to the Fermi level.Furthermore,the co-segregation ability of two solute atoms in the twin boundary increases with increasing the binding tendency of these two solute atoms in the boundary.Mn and Li or Mg show a relatively strong co-segregation ability in the twin boundary.Adding Mn to Zn-Li or Zn-Mg alloys can significantly enhance the resistance to fracture of twin boundaries.
基金Supported by the Natural Scientific Foundation of Shandong Province, China(NoZ2007B03)the Doctoral Fund of the Ministry of Education of China(New Teachers Fund)(No070422047)
文摘The enthalpies of mixing of L-arginine with 2,2,2-trifluoroethanol and their respective enthalpies of dilu- tion in aqueous solutions at 298.15, 303.15 and 310.15 K were determined as a function of the mole fraction by flow microcalorimetric measurement. These experimental results were analyzed to obtain heterotactic enthalpic interaction coeffieients（hxy , hxy , hxy） according to the McMillan-Mayer theory. The hxy coefficients between L-arginine molecule studied and 2,2,2-trifluoroethanol molecule in aqueous solutions at 298.15, 303.15 and 310.15 K were found to be all negative. The results were discussed in terms of solute-solute interaction and solute-solvent interaction.
