Cold spray is a promising potential material deposition process of which the main advantage is that the material to be sprayed is not heated to high temperatures. But one problem encountered is that the coatings for some powders are not well bonded to the substrate. The mechanisms of bonding of cold-sprayed coating to substrates are not at present clearly understood. This work considers the deposition of aluminum bronze by cold spray process onto stainless steel. The micro diffusion along the interface between the substrate and coating as well as the beta-phase depletion of the cold-sprayed coating is observed. Results obtained are important not only for understanding the interaction of the particles with the substrate but also for optimizing the spray parameters for the cold spray process.