While there are many welding processes you can utilize for cladding and hardfacing, not all are ideal for the deposition of large amounts of material where minimal heat and dilution are needed. The more common arc processes, such as gas tungsten arc welding (GTAW) or gas metal arc welding (GMAW), often require multiple layers to reach the proper chemistry and tend to deposit thicker layers with more heat input. To address these issues of arc processing, laser cladding with powder has been accepted; however, it has lower deposition rates and high “overspray” (material that does not stick to the clad). All of these approaches mean an increase in the total time it takes to complete the cladding process. By increasing the depositing rate while minimizing the amount of material needed to achieve the correct chemistry could save hundreds or thousands of pounds of clad material and result in significant cost savings for a company. A process that addresses these conditions is laser hot wire cladding, which may be a process worth considering if you clad large areas on an annual basis and would like to increase your production rate while minimizing your material costs. This white paper will focus on the advantages of laser hot wire cladding over other welding processes, outline the cost savings potential, and explain how to know if it’s the right process for your application.
Because of these characteristics, laser hot wire cladding has a lower dilution rate compared to other arc welding processes. Where other arc processes of similar deposition rates (GMAW or GTAW) have the dilution rates as high as 30 percent, laser hot wire cladding is similar to laser powder which is often in the little as 5 to 10 percent.
Powder laser cladding also offers many advantages over traditional arc welding methods. With laser powder cladding, all of the energy to heat and melt the powder and the substrate is coming from the laser. By using laser hot wire cladding with the same laser powder, some of the energy is coming from the resistance heating of the wire, which means you can melt the same amount of material faster.
Working with powder has many drawbacks. For instance, because most cladding processes feed the powder into the laser beam, a certain amount – typically around 10% – does not go into the puddle and therefore is wasted. So if you are using 100,000 lbs. of powder a year at $20.00/lb. and losing approximately 10% of it, that’s $200,000 of lost revenue.