By using a gas tunnel type plasma jet, the melting of aluminum alloy was carried out. In this plasma system high thermal efficiency could be obtained: the efficiency of this plasma jet was about 70%. The transferred energy from the plasma jet was large at a short operating distance. In this paper, the fundamental characteristics of this melting system were studied by changing the experimental conditions such as the distance from plasma torch, the power input to the torch. The melting time was increased as the melting distance was increased, which caused the decrease of the melting efficiency. This melting system had a higher melting efficiency when the power input (to_plasma torch) was large at a short melting distance. Furthermore, in order to investigate the property of melted aluminum alloy the thermal effect of plasma melting on the Vickers hardness of the specimen and the composition of the melted specimen were discussed. The hardness of this melting alloy became lower than that of as received aluminum alloy as well as the case of heat treatment.
Transactions of JWRI 21 (1), 17-22, 1992-06