Enthalpies of formation and Lattice parameters of

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Enthalpies of formation and Lattice parameters of
Al-Ni-Cu compounds
Student Rongxiang Hu
hurongx_at_iit.edu Hsin-Ning Su
suhsinn_at_iit.edu Advisor Prof. Nash
nash_at_iit.edu This
work was supported by the National Science
Foundation under grant No.DMR0209624
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Phase diagram of Al-Ni-Cu
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Cu-Ni binary phase diagram
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Enthalpy of formation of AlxNiyCuz compounds
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Data about Al-Cu and Cu-Ni

• Atomic crystal structure
• Al (f.c.c.) Ni (f.c.c.) Cu (f.c.c)
• Bonding length
• r0(AlCu) 2.3389 0.0004 Å
• r0(AlNi) 2.3211 0.0007 Å

The enthalpy of formation "dH" is the cohesive
energy of a compound relative to the
composition-weighted average cohesive energies of
its pure elements.
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XRD of Al-Ni-Cu compounds
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Lattice parameters of Al-Ni-Cu compounds
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Lattice parameters of Al-Ni-Cu compounds
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Lattice parameters of Al-Ni-Cu compounds
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Conclusion

• Enthalpy of formation for Al0.5Ni(0.5-x)Cux
  decreased linearly with Cu
• content increasing so did that of
  Al0.4Ni(0.6-x)Cux When Ni content is
• constant, enthalpy of formation of AlxNiyCuz
  decreased with Cu
• content increasing which might be due to the low
  cohesive energy
• between Al and Cu
• B2 and A1 phase was detected in the
  Al0.3Ni0.2Cu0.5 compound, and
• the lattice parameter were 2.886Angstrom and
  3.6423Angstrom
• respectively
• Lattice parameters of Al0.5Ni(0.5-x)Cux and
  Al0.4Ni(0.6-x)Cux increased linearly
• with Cu atomic fraction increasing, because the
  bigger atomic radius of Cu
• compared with Ni and the longer bonding length of
  Al-Cu than that of Al-Ni

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Future work

• Enthalpy of formation measurement of compounds in
  the A1 phase and
• other phases these compounds might be more
  ductile
• Study of other Al-Ni-X ternary system

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• Thank you!

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Al-Cu binary phase diagram