Lattice parameter of compounds in the AlNiCo ternary system

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Lattice parameter of compounds in the Al-Ni-Co
ternary system

• 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-Co at 1000C
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XRD of Al-Ni-Co B2 Phase
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XRD of Al-Ni-Co B2 Phase
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Optical microscopy
Al0.4Ni0.5Co0.1(unetched)
Al0.4Ni0.4Co0.2(etched)
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Different phases in Al0.4Ni0.5Co0.1
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XRD of Al0.4Ni0.5Co0.1
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Different phases in Al0.4Ni0.4Co0.2
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XRD of Al0.4Ni0.4Co0.2
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Lattice parameter of Al-Ni-Co B2 phase
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Lattice parameter of Al-Ni-Co B2 phase
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Lattice parameter of Al-Ni-Co L10 phase
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Intensity of XRD

• Relative intensity of powder pattern lines
• IF2p (1cos22?) e-2M/sin2?cos?
• F-----structure factor,
  Fhkl?fne2pi(hunkvn l wn)
• (un vn wn ) ----atom
  arrangement
• f ------atomic scattering
  factor, a function of
• atom kind.

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Relative Intensity of B2(100) simulation
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Conclusion

• With the increase of Co content, the lattice
  parameters of Al0.5Ni(1-x)Cox and
  Al0.4Ni(1-x)Cox decrease
• XRD showed that except B2 phase, L10(Martensite)
  and L12 (? phase) phase formed in the
  Al0.4Ni0.4Co0.2 and Al0.4Ni0.5Co0.1, which also
  can be seen in the optical and SEM pictures
• XRD intensity simulation indicated that the Co
  goes into the Ni sublattice for the
  Al0.5Ni(1-x)Cox compounds

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Future work

• Measuring the physical properties of some
  Al-Ni-Co compounds to find the effect of Co to
  properties of NiAl
• Determining the enthalpies of formation from B2
  to Martensite transformation using DSC
• Finding out the relationship between lattice
  parameter of the Al-Ni-Co L10 phase and content
  of Co
• Determining the defect in the compounds of
  Al-Ni-Co system
• Measuring the formation enthalpies of other
  Al-Ni-Co compounds and determining their lattice
  parameters

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Thank you !