Effect of stand-off distance in thermally sprayed copper coating

摘要

The present work demonstrates a two-step method to deposit copper over ABS plastic using electric arc thermal spray means. The energy dispersive spectroscopy confirmed the deposition of copper metal. The adhesive strength demonstrates an increasing trend as the stand-off distance increases from 11 to 17 cm, and decreases as the stand-off distance further increases till 23 cm. For surface roughness, porosity and coating thickness, an increasing trend was noticeable as the stand-off distance increases from 11 to 15 cm, and then assumes a decreasing trend till 23 cm of stand-off distance. The surface residual stress demonstrates decreasing course as the stand-off distance increases from 11 to 23 cm. Different factors engaged during the deposition of molten metal droplet on the ABS substrate such as thermal softening, oxide content, particle velocity and cooling rate dictated the characteristic outcome such as adhesive strength, roughness, porosity coating thickness and surface residual stress.