Slide 1

Status of AFRL characterization of Thermal Sprays for Engine Applications April 2, 2003 Robert Ware (937) 656-9146 Air Force Research Laboratory Susan Hill (937) 229-2109 John Ruschau (937) 656 9138 Nick Jacobs (937) 656-9115 University of Dayton Research Institute Robert Ware (937) 656-9146 Air Force Research Laboratory Susan Hill (937) 229-2109 John Ruschau (937) 656 9138 Nick Jacobs (937) 656-9115 University of Dayton Research Institute Slide 2 2 Thermal Sprays for Engine Applications Study Objectives Compare Performance of HVOF and Plasma Sprayed Coatings at room and elevated temperatures Fatigue Testing @ elevated temperature Delamination / Bond Strength Strain to Fracture Slide 3 3 High Temperature Fatigue Study Limited Fatigue Testing 0.010 thick coatings Detailed AFRL Characterization of a few points from PEWG Matrix Slide 4 4 High Temperature Fatigue Results 17-22 Steel, 300 F Slide 5 5 High Temperature Fatigue Results Inconel 901, 750 F Slide 6 6 Delam / Bond Strength Study Delamination after Loading, as a function of Life inch thick Flat Bars to facilitate bond button testing Measured by Immersion Ultrasonics (UT), Fluorescent Penetrant Inspection (FPI), and Bond Button Test Two thicknesses (3 mils, 10 mils) Five coatings HVOF: WC-Co; Cr 3 C 2 -20(Ni,Cr); T-400 PS: WC-Co; T-400 Slide 7 7 Sulzer Metco (#9-2) untested sample (calibration) 100% reflection (no delamination) good 0% reflection (total delamination) Nondestructive Inspection (NDI) for Delamination of Fatigue Specimens Ultrasonic Immersion Testing (Pulse Echo) 10 MHz, 0 deg, 0.25 probe diameter, 1 focus reflections from back wall show integrity of near wall NDI for Delamination, Previous Results Slide 8 8 9-2, Std (Untested) WC-Co-Cr NDI for Delamination, Previous Results WC-Co Delamination Inspection, R = -1, 160 ksi 3,500 cycles @ 160 ksi; R = -1, #23-9 10,000 cycles @ 160 ksi; R = -1, #9-9 WC-Co-Cr delaminates earlier than WC-Co Slide 9 9 9-2, Std (Untested) WC-Co-Cr NDI for Delamination, Previous Results WC-Co 100 cycles @ 185 ksi; R = -1, # 23-10 100 cycles @ 185 ksi; R = -1, # 9-10 1,000 cycles Delamination Inspection, R=-1, 185 ksi, 100 and 1000 cycles 1,000 cycles WC-Co-Cr delaminates earlier than WC-Co Slide 10 10 Delam / Bond Strength Study Loading in fatigue in 4pt Bend No area variation observed in ultrasonic inspection FPI showed cracking in thicker PS coatings Slide 11 11 Delam / Bond Strength Study Ultrasonic Inspection Results 4pt loading: Uniform attenuation observed next steps correlating to bond strength correlating to metallurgical mounts condition Slide 12 12 Delam / Bond Strength Study Fluorescent Penetrant Inspection Results 4 Point Loading: FPI showed cracking in 0.010 thick Plasma Sprayed WC-Co & T400 tension & compression 70 ksi, 1000 cycles no cracking in others WC-Co T400 0.010 0.003 Slide 13 13 Delam / Bond Strength Study Loading in Axial Tension Testing underway Slide 14 14 Delam / Bond Strength Study Ultrasonic Inspection Results Axial Loading Area variation as observed previously next steps correlating to bond strength correlating to metallurgical mounts condition Slide 15 15 Strain to Fracture Study Strain to Fracture (STF) Measured by Acoustic Emission in Axial Tension Two substrates (17-22; Inco 901) Three temperatures (R.T., 300F, 750F) Two thicknesses (3 mils, 10 mils) Five coatings HVOF: WC-Co; T-400; Cr 3 C 2 -20(Ni,Cr) PS: WC-Co; T-400 Slide 16 16 Strain to Fracture Study Test Setup Oven Transducer Slide 17 17 Strain to Fracture Study Sample Output Correlate loading to coating cracking events load, stress, strain and time stamp acoustic emission events: intensity, location, time stamp Slide 18 18 Thermal Sprays for Engine Applications Study Status High Temperature Fatigue Testing Complete Characterization of failed coupons ongoing Acoustic Emission Setup & Testing Imminent Bond Testing of Delaminations Altering Loading to try to induce delaminations