kylmäruiskutus

Kylmäruiskutus, also known as cold spray or cold gas spray, is a solid-state coating and material deposition process. In this method, fine powder particles of a feedstock material are accelerated to high velocities through a de Laval nozzle by a heated gas, typically nitrogen or helium. The gas is heated to a temperature below the melting point of the powder particles, hence the term "cold."

As the particles impact a substrate, they deform and adhere to the surface, building up a coating layer by layer. The kinetic energy of the particles is the primary driver for adhesion, causing plastic deformation of both the particles and the substrate at the point of impact. This low-temperature process is advantageous for coating heat-sensitive materials or substrates, as it minimizes thermal effects like oxidation, phase transformation, or residual stresses.

Kylmäruiskutus can deposit a wide range of metallic and alloy powders, including copper, aluminum, zinc, nickel, and their alloys. It is used in various industrial applications such as wear-resistant coatings, corrosion protection, repair of worn parts, and additive manufacturing. The process allows for the deposition of dense, well-adhered coatings with minimal porosity and excellent mechanical properties. Its ability to work with materials that are difficult to process using traditional methods like welding or thermal spraying makes it a versatile technology.