Correlation between Al2O3 particles and interface of Al–Al2O3 coatings by cold spray

Abstract Al–Al 2 O 3 composite coatings with different Al 2 O 3 particle shapes were prepared on Si and Al substrate by cold spray. The powder compositions of metal (Al) and ceramic (Al 2 O 3 ) having different sizes and agglomerations were varied into ratios of 10:1 wt% and 1:1 wt%. Al 2 O 3 particles were successfully incorporated into the soft metal matrix of Al. It was found that crater formation between the coatings and substrate, which is typical characteristic signature of cold spray could be affected by initial starting Al 2 O 3 particles. In addition, when the large hard particles of fused Al 2 O 3 were employed, the deep and big craters were generated at the interface between coatings and hard substrates. In the case of pure soft metal coating such as Al on hard substrate, it is very hard to get proper adhesion due to lack of crater formation. Therefore, the composite coating would have certain advantages.