Abstract
Tungsten particles were sprayed by a novel plasma torch with hybrid water-gas stabilization (WSP®-H). Several spraying parameters were varied – arc current, argon flow rate, carrier gas flow rate and spraying distance. The temperature and velocity of the individual particles were monitored by the DPV 2000 optical sensor. Individual splats were collected on polished stainless steel substrates and analyzed by SEM to assess their melting, flattening and/or fragmentation. These features were correlated with the basic in-flight particle characteristics and conditions for production of dense coatings were sought for. Significant dependence of the splats morphology on spraying parameters was found, and important improvement of particle melting at WSP-H over conventional water stabilized plasma torch (WSP) was registered.
