Original Date: 11/03/1996
Revision Date: 01/18/2007
Information : Enhanced Gun Bore Protection
Oak Ridge National Laboratory (ORNL) is exploring new coatings and deposition methods for replacing the hexavalent chromium coatings in 120 mm gun tubes on M256 Abrams tanks. Although used as an electroplated bore coating in most gun barrels, hexavalent chromium creates environmental problems. The replacement coating should be environmentally safe, be able to withstand the 3500°K flame temperatures of modern high-impulse propellants, and provide a gun barrel life of 1500 rounds.
ORNL has identified rhenium and molybdenum-rhenium alloys as potential plating replacements. The study indicates these materials would be able to withstand the gaseous contaminants and high temperatures of modern high-impulse propellants. In addition, ORNL is evaluating deposition methods for ease of fabrication, physical characteristics of the lining, and cost considerations. Methods being addressed include physical vapor deposition (magnetron sputtering) and thermal spray deposition (plasma spraying). Although the study currently focuses on smooth bore gun barrels, ORNL anticipates the research to include rifled barrels in the near future.
For more information see the
Point of Contact for this survey.