Electromagnetic powder deposition experiments

The Department of Defense (DoD) and commercial entities are dependent on ch emical plating and coating processes to replace worn or eroded material on damaged parts. Logistics Centers have been forced to consider replacement m aterials for repair operations due to the tightening of government regulati ons on the use of toxic and hazardous materials. This paper describes a new process capable of fulfilling many of these requ irements. Existing state of the art thermal sprag processes (HVOF, D-gun, p lasma spray) are limited to powder velocities of about 1 km/s because they rely on the thermodynamic expansion of gases. A new thermal spray process u sing electromagnetic forces can accelerate powder particles to a final velo city in excess of 2 km/s, At this velocity, powder particles have sufficien t kinetic energy to melt their own mass and an equivalent substrate mass on impact. The energetics of the process allow fusion bonding of greater stre ngth than that created by low velocity processes as well as improved coatin g density. This paper will describe the laboratory system designed and constructed to conduct proof of principle experiments, Results of the experiments will be presented along with high speed photographs of powder particles confirming system modeling and performance. The paper will conclude with a discussion of the future direction of the program.