Oxidation, Volatilization, and Redistribution of Molybdenum from TZM Alloy in Air

Smolik, Galen Richard ; Petti, David Andrew ; Mccarthy, Kathryn Ann ; Schuetz, Stanley Thomas

Idaho National Laboratory

关键词: Radioactivity;    High Temperature Strength;    Re-Deposition;    Safety Issue;    Inertial Fusion;   

DOI  :  10.2172/911479
RP-ID  :  INEEL/EXT-99-01353
RP-ID  :  DE-AC07-99ID-13727
RP-ID  :  911479

美国|英语

来源: UNT Digital Library

【 摘 要 】

The excellent high temperature strength and thermal conductivity of molybdenum-base alloys provide attractive features for components in advanced magnetic and inertial fusion devices. Refractory metal alloys react readily with oxygen and other gases. Oxidized molybdenum in turn is susceptible to losses from volatile molybdenum trioxide species, (MoO3)m, in air and the hydroxide, MoO2(OH)2, formed from water vapor. Transport of radioactivity by the volatilization, migration, and re-deposition of these volatile species during a potential accident involving a loss of vacuum or inert environment represents a safety issue. In this report we present experimental results on the oxidation, volatilization and re-deposition of molybdenum from TZM in flowing air between 400 and 800°C. These results are compared with calculations obtained from a vaporization mass transfer model using chemical thermodynamic data for vapor pressures of MoO3(g) over pure solid MoO3 and an expression for the vapor pressures of MoO2(OH)2 from the literature. Calculations correlate well with experimental data.