EROSION OF A COPPER CATHODE IN A NONSTATIONARY ARC SPOT. 
I. EXPERIMENTAL INVESTIGATION

A. M. Esipchuk,a, b A. Marotta,a  
and L. I. Sharakhovskiib 

UDC 621.387.143.014.31

A study has been made of the dependence of the erosion 
of a copper cathode of an electric-arc heater on the basic operating 
parameters: the arc current, the velocity of movement of an arc spot, 
and the temperature of the electrode surface. The experiments were 
conducted in a coaxial electric-arc heater with a magnetic movement 
of the arc in an air medium for an arc current of 95-480 A and 
a magnetic field of 0.005-0.417 T. The duration of the experiment, 
the axial velocity of a plasma-forming gas, and the flow rate of a 
cooling water were held constant. It has been shown that there are 
two different erosion regimes: the microerosion regime characterized 
by a weak dependence on the current and the macroerosion regime with 
a strong dependence on the current; the transition from one regime 
to the other is realized upon the attainment of the critical value 
of the current, dependent on the magnetic field and the thermal regime 
of the electrode. The existence of a velocity interval in which the 
specific erosion is minimum has been shown, which confirms the predictions 
of the earlier thermal model of erosion of cold electrodes.

aGleb Wataghin Institute 
of Physics, Campinas State University, Campinas, Brazil (Instituto 
de Fisica "Gleb Wataghin," Universidade Estadual de Campinas, Sao Paulo, Brasil); email: aruy@ifi.unicamp.br; 
A. V. Luikov Heat and Mass Transfer Institute, 
bNational Academy of Sciences of Belarus, 15 P. Brovka Str., Minsk, 
220072, Belarus; email: leonidsh@tut.by. Translated from Inzhenerno-Fizicheskii 
Zhurnal, Vol. 77, No. 2, pp. 106-111, March-April, 2004. Original 
article submitted October 13, 2003.