HIP AND HEAT TREATED TITANIUM CASTINGS FOR FORGED HELICOPTER COMPONENT REPLACEMENT

A cast titanium helicopter main rotor hub is being fabricated and evaluated for potential production implementation under an AMMRC* sponsored MANTECH program. A 250 pound casting is being developed to replace an 850 pound titanium forging to produce a 158 pound finish machined rotor hub. Because of reduced strategic material usage and the reduced machining costs, it is estimated that a significant savings will result from the casting substitution. Preliminary testing has shown that a hot isostatic processed (HIP) and heat treated casting possesses equivalent properties to a forged and heat treated part. Both small scale and full scale component testing are being conducted to verify that the cast hub is physically and functionally interchangeable with the production forged hub without sacrificing aircraft performance. This paper will discuss the processing, inspection techniques and testing involved to fabricate the HIP and heat treated titanium casting.