Metal Coatings Deposited by Pulsed Vacuum-Arc Plasma Accelerator on Different Solid Substrates

A vacuum-arc pulsed plasma accelerator (APPA) operating at a discharge current of 750 A and a pulse duration of 110 μs with a repetition rate of 5 Hz was employed to deposit thin films and coatings under low- and medium-vacuum conditions. The aim of this study was to obtain metal coatings suitable for potential applications in the energy and chemical industries. SEM, AFM, and XRD techniques were used to investigate the structure and morphology of coatings formed on metallic and insulating substrates under the following conditions: residual pressure of 10−2–10−4 mbar and deposition times of 10–30 min. Under medium-vacuum conditions, thin and non-uniform metallic films with thicknesses ranging from 0.4 to 1.9 μm were deposited on metal substrates. The morphology of thick films deposited under low-vacuum conditions consisted of spherical metal particles of various sizes (0.1–1 μm), containing up to 30% carbon and 28% oxygen. On silicon substrates, spherical microparticles up to 4 μm in diameter with thin shells approximately 0.3 μm thick were formed. One possible mechanism for microsphere formation—the desorption of residual gases by the coating material—is discussed. The potential of the APPA method for producing metal shells, relevant to powder manufacturing due to the high energy density of the process and the intrinsic purity of vacuum technologies, is also considered. Porous coatings obtained using the APPA technique may be applicable in the fabrication of energy-related materials, such as battery anodes.