Surface Treatments for Stainless Steel Actuators

ABSTRACT: Stainless steel ballscrew components, such as those found in landing gear and flap actuators on the C-130 aircraft, experience wear and subsequent failure due to corrosion, contamination and foreign object damage (FOD). High"dither"conditions, where the actuator undergoes a constant short-travel, high-frequency movement to maintain level flight, can also induce wear on actuator ballscrew and bearing components. The Air Force, as well as the commercial airline industry, incurs a high maintenance burden associated with frequent inspections and applications of lubricants in the field in an effort to keep actuators functioning at a high availability rate. In order to provide improved wear and damage tolerance of stainless steel and steel ball screws/jack screws for aircraft subsystems, IBC Materials and Technologies Inc. will develop a novel dual-layer surface treatment that combines surface hardening with a Diamond Like Carbon (DLC) coating. This dual-layer surface treatment will significantly increase the surface hardness as well as the lubricity of the steel actuator substrate, while maintaining high fatigue performance. Increasing the component hardness to levels higher than that of contaminants, and improving lubricity at/below levels of film lubricants, will help reduce maintenance and extend the lives of the actuators. BENEFIT: IBC"s advanced dual-layer Diamond Like Carbon (DLC) surface treatments will solve the current maintenance and wear issues caused by environmental contamination and corrosion of aircraft actuators. The increase in both surface hardness and lubricity of the steel actuator substrate will enable dry-running, maintenance free operation of the ballscrew actuators, significantly reducing inspection/maintenance and extending the wear lives of the actuators. IBC will apply the dual-layer DLC system using a single industrial processing furnace, which will minimize process time and overall processing cost.