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Outstanding technical issues. HCAT Program Review August 2001 Toronto. Last meeting status Confusing results Previous HCAT generic data and beach exposure showed HVOF better C-HCAT showed same US-HCAT LG JTP data showed overall HVOF corrosion looked worse, but uniform rather than pitted
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Outstanding technical issues HCAT Program Review August 2001 Toronto
Last meeting status Confusing results Previous HCAT generic data and beach exposure showed HVOF better C-HCAT showed same US-HCAT LG JTP data showed overall HVOF corrosion looked worse, but uniform rather than pitted Data from AFRL on cracking and corrosion Current status Additional US testing done per Boeing methods Canadian corrosion testing complete Very interesting hydrogen embrittlement/stress corrosion cracking data Corrosion
Last meeting status Integrity (spalling at high load) still a concern Looked fine for commercial use High compressive residual stress coatings looked good concern over relying on stress Indications of satisfactory performance from initial tests of new parameters developed at Hill by Jerry S Big bar tests planned as unsure if small bars properly represent HVOF material Air Force and Navy have different requirements based on different use conditions land-based vs carrier-based There are different testing philosophies standard samples and coupon tests (lab procedures) large axial samples (Big Bars) to measure response to applied stress (Navy) large bend bars to simulate what happens in service (Air Force, Goodrich) rig tests (OEMs - Messier-Dowty, Goodrich) flight tests (airlines - Delta) Coating integrity - last meeting
Coating integrity - this meeting • To be covered this meeting • Additional data on newly optimized Hill 0.005” - 0.015” WC-Co coatings (Jerry Schell, John Sauer) • Hill/ALGLE bend tests on A-10 pistons • Additional data on 0.003” WC-Co coated at Southwest Aero • NAWC big bar high load, low cycle integrity tests • Rig tests (Messier-Dowty and Goodrich) • Flight tests Good and not-so-good results: Looks as though performance requirements can be met. But, depends on thickness and on deposition parameters (how the coating is optimized) - to be discussed by Jean-Gabriel and Jerry Schell