In recent years, Cold Spray (CS) technology gained more and more attention within scientific and industrial communities and numerous studies are focusing on increasing the awareness of cold spray process as proven viable innovative Additive Manufacturing (AM) process. This work focuses on the Cold Spray process, especially High-Pressure Cold Spray (HPCS) and points out the unique technical properties of the technology. Most important advantages and disadvantages in comparison to other AM technologies will be discussed as well.

Unique to the innovative Cold Spray process is that the metal material which is added onto a substrate is not molten at all, it’s a cold deposition process. The feedstock for Cold Spray is metal powders and during the process the metal particles are accelerated to very high speeds (up to 2 -3 times supersonic speed). The high kinetic energy in the process leads to plastic deformation of the metal particles on the substrate, which assures very good bonding between the particles and the substrate. Building up layer by layer assures that the so-called hammering effect generates high densities and low porosities in the sprayed material.

Unlike, high-temperature AM processes e.g. fusion based processes, Cold Spray retains the original properties of the feedstock, to produce oxygen-free deposits and to maintain the underlying substrate materials during manufacture. Therefore, Cold Spray technology can be used for corrosion and wear resistant coatings, as well as for classical repair applications and building up 3-dimensional parts.

In space applications, materials with high strength to weight ratios and properties such as excellent tensile strength, fatigue strength, and fracture toughness combined with low density are needed. However, there are specific parts, such as launcher propulsion system components, where the focus of the properties is on heat conductivity, mechanical strength at elevated temperatures, and different material combinations. Present work reports the feasibility of Cold Spray Additive Manufacturing (CSAM) of such components with outstanding mechanical properties, large dimensions, and specific geometrical complexity to demonstrate the potential of the CSAM process as an innovative process for additive manufacturing.

The cold deposition process guarantees that substrates do not suffer from thermal energy input, i.e the components in general do not deform, compared to other high-temperature processes. Therefore, CSAM is also used in combination with other AM technologies, to add a second different metal material on a 3d printed part or for repair applications. Repair parts have already been heat treated and by using a high-temperature AM process the part will undergo at least a partial second heat treatment, which in many cases is not acceptable. Finally, this work shows a few repair applications while using Cold Spray technology.