Abstract
Thermodynamic calculations were carried out to simulate impurity removal from refractory metals by Ar-H2 plasma arc melting. The calculations enable us to estimate the impurity removal degree. Numerical agreement between the experimental and calculated results for the base metals Ti, V, Zr, Nb to Ta improve in that order. Addition of H2 to the plasma gas results in faster transfer of the system toward equilibrium-like state, while the equilibrium composition of the metal does not depend on the plasma gas, but on temperature. The examined impurities transfer to the gas phase in the form of atoms while hydride formation makes a minor contribution; thus, the major factor for better metal purification with Ar-H2 plasma is considered to be an increase in the molten-metal temperature.
Original language | English |
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Pages (from-to) | 849-852 |
Number of pages | 4 |
Journal | Vacuum |
Volume | 47 |
Issue number | 6-8 |
DOIs | |
Publication status | Published - 1996 |
Keywords
- Hydrogen plasma
- Plasma arc melting
- Refining
- Refractory metals
- Thermodynamic simulation
ASJC Scopus subject areas
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films