Evaluation of Powder's Thermal Behavior in Plasma Transferred-Arc Space (Ⅱ)——Study on Heat Transfer Between Powder Particle and Plasma

The heating processes of Fe-base alloy and B₄C particles in the plasma transferred-arc(PTA) space were theoretically evaluated in this article based on heat conduction theories.It was found that most of the Fe-base particles would be fully melted while they transporting through the central plasma field with 200 A_surfacing currents.And the particles with a diameter less than 0.5×10^-4 m migth be fully evaporated.However,for the boron carbide(B₄C) particles,only the one with a diameter less than 0.5×10^-4 m could be melted in the same PTA space.Most of B₄C particles are only preheated at its soild state when they were fed through the central field of PTA plasma when the surfacing current is equal or less than 200 A.When the arc current was smaller than 100 A,only the particles smaller than 0.5×10^-4 m could be melted in the PTA space for the Fe-base alloy.Almost none of the discussed B₄C particles could be melted in the 100 A PTA space.