Coating formation of electro-thermal explosion spray in constrained capillary tube

The polyethylene capillary tube with 7 mm inner diameter was used for the experiment of electrical spraying of Mo wire.The coating topography,the shape and thickness of cross section,and the bonding between coating and substrate were analyzed.The results shows that explosion products of Mo wire in a constrained capillary tube forms a spraying spot,which consists of central coating and outer adhesive layer.When the spraying distance is 5~8 mm,the central coating is compact and uniform,bonding between coating and substrate is good,the diffusion occurs in the interface between them.While with the spraying distance increasing,the outer adhesive layer vanishes.Large coating could be formed by overlapping single spraying spot reasonably,and thick coating could be obtained by spraying several times.