What Does Laser Alloying Mean?
Laser alloying is a metal surfacing process that uses a laser beam as the source of energy. Prior to the laser alloying process, a coating material is deposited onto the base material. The coating material and the base material are then targeted by the laser beam. The laser beam fuses, or alloys, these two materials together.
Applications for laser alloying often include items that need increased wear resistance, such as certain areas on tooling. Another application is increasing the corrosion resistance of a base material. Using corrosion resistant materials on the surface of a susceptible base material can greatly increase its resistance to oxidation, so long as the materials are compatible with one another.
Corrosionpedia Explains Laser Alloying
One of the advantages of laser alloying is that the amount of base material diluted during the alloying process can be kept to a minimum. With the proper laser beam parameters, heat input can be significantly lower than other alloying, surfacing or cladding methods. This low dilution allows the coating material to retain many of its original properties. The low heat input that can be achieved by laser alloying reduces the size of the heat affected zone (HAZ), which allows the base material to retain much of its original properties. The reduced heat affected zone also means that short cooling times can be achieved, which can result in coatings with high hardness and excellent wear resistance.
The coating material can be applied in a variety of ways. One common way is as a film. This film must be very thin, about 100 microns, so as to not require large amounts of energy to melt it. Another way to apply the coating material is through a powder that is continuously fed to the base material in front of the laser beam.