Lightweight Gearbox Development for Propeller Gearbox System Applications Potential Coatings for Titanium Alloy Gears

摘要

The objective of the program is to develop the capability of titanium gears to sustain 126 million repetitive stress cycles at a surface contact stress of 132,000 psi (based on steel modulus of elasticity. The achievement of this goal will make titanium gears significantly attractive for the 1975 time period. Optimum titanium material composition was selected to provide desirable strength properties and compatibility to the selected surface coating system. Plated surface coatings, bonding techniques, heat treat processes, and surface lubrication coatings were investigated to provide an optimum system which would withstand the scheduled test requirements. Iron-plated coatings which were diffusion bonded to the titanium core and then carbonitrided to provide surface hardness were selected as the most promising system. (Author)