Effect of MeV ion irradiation on the coefficient of thermal expansion of Fe-Ni Invar alloys: A combinatorial study

Xuan Zheng, David G Cahill, Ji Cheng Zhao

Research output: Contribution to journalArticle


The effect of low-dose MeV ion irradiation on the thermal conductivity and coefficient of thermal expansion (CTE) of Fe-Ni alloys has been studied over the entire composition range using a combinatorial method. With our experimental precision of ±5%, the thermal conductivity of Fe-Ni alloys is unchanged by 2.3 MeV Ar+ irradiation at a fluence of 1.2 × 1014 ions cm- 2. The CTE of Fe-Ni Invar alloys with Ni concentrations between 30 and 37 at.% increases significantly upon 2.3 MeV Ar+ irradiation. At the Invar composition of Fe65 Ni35, the CTE increases from 0.5 × 10- 6 K- 1 before ion irradiation to 4.3 × 10- 6 K- 1 after irradiation for an ion fluence of 1.2 × 1014 ions cm- 2 or, equivalently, 0.1 displacements per atom. We attribute this increase in CTE to changes in atomic short-range order created by ion irradiation.

Original languageEnglish (US)
Pages (from-to)1236-1241
Number of pages6
JournalActa Materialia
Issue number4
StatePublished - Feb 1 2010



  • Coefficient of thermal expansion
  • Combinatorial study
  • Invar effect
  • Ion irradiation

ASJC Scopus subject areas

  • Ceramics and Composites
  • Metals and Alloys
  • Polymers and Plastics
  • Electronic, Optical and Magnetic Materials

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