An Experimental Study On Electrothermal Explosion Ultrahigh-Velocity Directional Spraying Technology

In the past tens of years, behaviours of the electrical explosion have been studied, but the mechanism of electrical explosion has not been throughoutly recognized yet.As a new-type thermal spraying technology, the electrothermal explosion directional ultrahigh-velocity spraying method has many unique advantages over the conventional spraying technologies, and possesses a quite capacious foreground in applications. However, it has attracted more attentions to produce ultrafine particles using the electrical explosion technology domestically and abroad currently. Excepting Japan, it has not been reported on the research of the electrothermal explosion spraying technology.Based on a great deal of experiments, the properties of WC-Co and Ti6A14V coatings prepared by self-designed spraying device, and energy-utilization ratio during the electrothermal explosion were studied and analyzed in this paper. The main work is as follows:1 The energy-utilization ratio during the heating of metal foils was calculated when the charging voltage is 4.0kV, 4.5kV and 4.6kV respectively. The properties of current, voltage, power and the metal foil resistance during the electrothermal explosion were analyzed in datail. The bihaviour and character of the electrothermal explosion were studied.2 The WC-Co and Ti6A14V coatings were prepared using the electrothermal explosion directional ultrahigh velocity spraying device. The microhardness, microstructure and grain size of the coatings were measured. Experimental results show that the microhardness of coatings are much higher than that of the original, and the coating contains quite a number of nanoparticles under 1 OOnm. The average grain size of WC-Co and Ti6A14V coatings is 200nm and 160nm respectively.