Abstract
The preparation of Cu based coatings, as well as a novel method for their fusion to a substrate using an air furnace, was studied. Optical microscopy was used to characterise the morphology of the precoated substrate (i.e. the coating before fusion) as well as the morphology and coating porosity of the Cu coating (i.e. the coating after fusion). The cross-section of the Cu coating was further observed by scanning electron microscopy and energy dispersive spectroscopy. The results showed that the batter contained 2·5 wt-% glycerins, and alcohol was used as the thinner. The smooth surfaces of the precoatings were smooth and without bubbles when they were heated for 120 min at 170°C. Diffusion, as well as 2 wt-% ammonium chloride, significantly contributed to the higher adhesion and cohesion strength after remelting in the furnace. The coating exhibited a dense structure with a faultless interface.
Acknowledgement
This research was supported by the National Natural Science Foundation of China (grant no. 51205001) and Scientific research fund for young of Anhui Polytechnic University (grant no. 2012YQ26).