Diode Laser Technology for Directed Material Deposition (DMD) Processes

The successful deployment of mobile battlefield repair for an agile army requires fast diagnosis and repair and/or replacement of damaged parts. Significant time compression and a compact footprint will be needed for mobile repair to serve in the field. The Direct Metal Deposition (DMD) offers promise due to its closed loop control of the dimension, however, the build rate or deposition rate has to be enhanced. Deposition rate enhancement for a machine with this limited foot print is a challenge since it limits the type, size and power of the laser energy source. Diode laser technology offers a solution due to its high power efficiency and small foot print, in comparison to CO2 and Nd:YAG systems. The Phase I program has demonstrated that laser aided DMD is possible with a 300 Watt diode laser having a wavelength of 810nm, with deposition rate comparable or slightly higher than that for CO2 laser of equivalent power. The goal for the Phase II is to develop a fiber-coupled diode laser based, DMD system platform, scalable to reach the high deposition rate goal of 8-10 inch3 per hour using a high power fiber-coupled diode laser. In order to achieve the stated goal, the Phase II program will construct a 5-axis DMD system with a 1 kW fiber coupled diode laser (the highest power available today), complemented by a research program for high deposition rate using a multi- kilowatt CO2 laser to provide a road map for future higher power systems. As a result of the Phase II, a diode laser based DMD system will be ready for commercialization that will accept higher powered diode lasers as they become commercially available, and its performance will be fully understood at those higher laser power levels. High power diode laser DMD technology will enable the introduction of DMD to the high volume manufacturing environment. POM is currently developing an engine application for the U.S. automotive industry that is designed to reduce complexity and cost, while improving the performance of the engine. This is the first target commercial application for diode laser DMD technology.