Evaluation Methodology for Surface Engineering Techniques to Improve Powertrain Efficiency in Military Vehicles

The Assistant Secretary of Defense for Research and Engineering (ASDR&E) is sponsoring a research effort to investigate whether surface engineering techniques, to include superfinishing and the application of nickel-based coatings, can yield tangible gains in power transfer efficiency within military vehicle drivetrains. This report details the experimental methodology developed by the U.S. Army Research Laboratory to characterize efficiency and durability improvements available through the application of these surface engineering techniques to various mechanical components. The primary goal of the initial phase of evaluation is to experimentally measure the efficiency of gears and other tribological components with and without these surface treatments. At the basic research level, these experiments are conducted on test coupons. At the applied research level, experiments are conducted on a subsystem component of a vehicle drivetrain. A parallel basic research thrust includes computational modeling of interacting gears to advance predictive tools for improved gear surface design. Initial durability studies characterize the fatigue properties of each technique. Finally, friction and wear measurements are conducted on specimens representative of diesel engine components, in order to determine any benefits of surface treatment to reciprocating mechanical components. The original document contains color images. Prepared in collaboration with Ohio State University under grant no. W911NF-10-2-0033, and Southwest Research Institute.