MIXING OF “TANTALUM-CARBON STEEL” SYSTEM BY COMPRESSION PLASMA FLOW

Abstract

A microstructure and phase and element compositions of a plasma-mixed “tantalum/U8A carbon steel” system have been investigated. Surface alloying of carbon steel with tantalum has been performed using a compression plasma flow (CPF). In this technique, the action of relatively short (~100 μs) and high-energy (up to 20 J/cm2) plasma pulses leads to the melting of the near-surface layer of the steel substrate together with the pre-deposited Ta film (~1 μm thick). A rapid liquid-phase mixing in the molten state occurs, resulting in the formation of new phases during fast re-solidification. It is observed that plasma treatment of the system causes both tantalum nitride and the tantalum-iron intermetallic compounds to form.