Improved Gear Carburization Process

Carburization of steel alloys is a common practice used to increase the longevity of gear interfaces. By increasing the amount of carbon present in the near surface region of the steel, the hardness of the outer region of the material can be increased while maintaining ductility and toughness within the core of the part. Multiple processes exist for carburizing steel components with gas carburization and vacuum carburization being the most common. Both processes rely on gas circulation to carry carbon to the surface of the work piece. In parts with complex geometry, such as gear teeth or cavities, gas circulation may be restricted which limits the amount of carbon that can be transferred to the workpiece. Therefore, an innovative carburization process is sought that can provide uniform carbon coverage and case hardening depth for parts with complex geometries, such as internal spline gears. In response to Navy SBIR solicitation N102-142, United Protective Technologies, LLC (UPT) proposes the use of a modified plasma assisted chemical vapor deposition technique to provide uniform case hardening depth to parts with complex geometry.