|Acquisition Program: ||PMA 261 CH-53K Heavy Lift Helicopter Program|
| ||RESTRICTION ON PERFORMANCE BY FOREIGN CITIZENS (i.e., those holding non-U.S. Passports): This topic is “ITAR Restricted”. The information and materials provided pursuant to or resulting from this topic are restricted under the International Traffic in Arms Regulations (ITAR), 22 CFR Parts 120 - 130, which control the export of defense-related material and services, including the export of sensitive technical data. Foreign Citizens may perform work under an award resulting from this topic only if they hold the “Permanent Resident Card”, or are designated as “Protected Individuals” as defined by 8 U.S.C. 1324b(a)(3). If a proposal for this topic contains participation by a foreign citizen who is not in one of the above two categories, the proposal will be rejected.|| Objective: ||Develop a robust carburizing method for deep internal splines with a high aspect ratio.
|| Description: ||The most common carburizing processes for aerospace gearing are conventional gas carburizing and vacuum carburizing. Both of these methods rely on carburizing gas circulation to achieve uniform carburization of surfaces. For both carburizing methods, a high part aspect ratio (e.g. internal bore length to the internal bore diameter ratio of greater than 3:1) can cause a reduction / restriction of gas circulation to the internal volume of the part, which limits the producibility of the carburized internal features such as splines.
Innovative carburizing processes are sought for internal, potentially high aspect ratio surfaces that provides uniform coverage and case hardening depth and the avoidance of free-carbon formation or sooting. Target applications for this technology are gears ranging in size from 4 to 44 inches in diameter, including Herringbone Pinions with an internal aspect ratio of approximately 5:1. The proposed process should also be efficient in energy usage and time allotment and conducive to mass production.
|| ||PHASE I: Develop the concept and demonstrate the technical feasibility of the proposed carburizing method. Define mass production requirements and obstacles.
|| ||PHASE II: Develop and demonstrate the process through the carburization of representative internal spline samples along with evaluation and testing of the samples.
|| ||PHASE III: Complete all required qualification/certification testing and transition the technology to the Original Equipment Manufacturers (OEM's).
PRIVATE SECTOR COMMERCIAL POTENTIAL/|| ||DUAL-USE APPLICATIONS: An improved internal gear carburization process would be beneficial for commercial aviation, automotive and commercial and military nautical applications.
|| References: ||
1. AMS-2759/6 - Gas Nitriding and Heat Treatment of Low-Alloy Steel Parts. http://www.sae.org/technical/standards/AMS2759/6B
2. AMS-2759/7 - Carburizing and Heat Treatment of Carburizing Grade Steel Parts. http://www.sae.org/technical/standards/AMS2759/7A
3. Osterman, V.M., (2005, September). Heat Treating: Development Experience in Low-Torr Range Vacuum Carburizing. Industrial Heating. http://www.industrialheating.com/Articles/Feature_Article/9bb06f4ed965e010VgnVCM100000f932a8c0|
|Keywords: ||Carburize; Gear; Transmission; Hardening; Pressure; Gas|