Structural Integrity of Metal Deposits Obtained Using Cold Spray Solid-State Deposition

In the field of solid state metal deposition, bonding is induced based on the kinetic energy of the process. Cold spray, as the main technology in this field, is a relatively novel technique for depositing thin and thick coatings as well as three-dimensional large components at high production rates. In this process, particles of powder feedstock are directed towards the substrate using a heated propellent gas at supersonic velocities. The successive impacts of the particles result in a robust bond with the substrate as well as the previously deposited particles. The flexibility, high production rate, and high deposition efficiency have made cold spray a promising candidate for a wide range of applications, ranging from functional coatings, and repair applications to the production of freestanding parts. Innovative applications require a certain level of mechanical properties to cope with the prescribed service regulations. In this article, state of the art and the recent achievements on the structural integrity of solid-state deposits by cold spray are reviewed. Special attention is devoted to the effects of processing parameters and pre- and post-deposition treatments on static mechanical properties such as adhesion and cohesion strength as well as fatigue performance of the deposits.