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

✍ Scribed by Xuan Zheng; David G. Cahill; Ji-Cheng Zhao

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 268 KB
• Volume: 58
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2009.10.024

✦ Synopsis

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 þ irradiation at a fluence of 1:2 Â 10 14 ions cm À2 . The CTE of Fe-Ni Invar alloys with Ni concentrations between 30 and 37 at.% increases significantly upon 2:3 MeV Ar þ irradiation. At the Invar composition of Fe 65 Ni 35 , the CTE increases from 0:5 Â 10 À6 K À1 before ion irradiation to 4:3 Â 10 À6 K À1 after irradiation for an ion fluence of 1:2 Â 10 14 ions cm À2 or, equivalently, 0.1 displacements per atom. We attribute this increase in CTE to changes in atomic short-range order created by ion irradiation.