Influence of Acetylene on Ti Target Poisoning During Pulse-Enhanced Vacuum Arc Evaporation

Vacuum arc evaporation is a prospective technique to fabricate hard and wear material due to its high ion energy and plasma density. Nevertheless, target tends to be poisoned by the compound layer in common reactive gases such as acetylene. Then the coating deposition rate and the properties of the coatings would be strongly influenced. Thus, the formation of the compound layer has to be inhibited. Previous studies pointed out the potential of pulse-enhanced vacuum arc evaporation mode for inhibiting the formation of the compound layer. Within the presented study, motion of group spots (GSs), optical emission spectra, and substrate current based on PEVAE mode were examined entirely. The result shows that the area ratio of the compound layer in the target was decreased from about 75% to 42%. The ionization degree of titanium and mean substrate current could be substantially increased by up to 40% and 100%, respectively, in a mixture gas of nitrogen and acetylene due to larger plasma density indicated by higher spectra intensity of plasmas. All of the above made PEVAE prospective candidate to inhibit the formation of the compound layer. Beyond this PEVAE would lead to higher coating rate and denser coating in nitrogen plus acetylene atmosphere.