1 / 17

Kinetic Metallization

Kinetic Metallization. Application of Oxidation/Corrosion Resistant Coatings to Rocket Engine Combustion Chamber Liners. AeroMat 2004 June 10, 2004 Ralph Tapphorn and Don Ulmer David Grimmett, Boeing-Rocketdyne Linus Thomas-Ogbuji, NASA-GRC. Overview. Introduction to Kinetic Metallization

bolick
Download Presentation

Kinetic Metallization

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Kinetic Metallization Application of Oxidation/Corrosion Resistant Coatings to Rocket Engine Combustion Chamber Liners • AeroMat 2004 • June 10, 2004 • Ralph Tapphorn and Don Ulmer • David Grimmett, Boeing-Rocketdyne • Linus Thomas-Ogbuji, NASA-GRC

  2. Overview • Introduction to Kinetic Metallization • Application • Oxidation/Blanching Resistant Coatings for Combustion Chamber Liners • Coating Properties • Tensile Properties • Thermal Conductivity • Oxidation Test Results • TGA • Cyclic Oxidation • Summary/Future Work

  3. Kinetic Metallization • Impact Consolidation Process • Feed-stock: fine powder • Accelerant: inert light gas • Solid-state Consolidation • No Bulk Melting • No Liquid Chemicals • Environmentally Innocuous • No Particle or Hazardous Gas Emission

  4. He TCU PFU Process Flow • Powder fluidized using pressurized He gas (PFU) • Powder/gas mix thermally conditioned to improve deposition efficiency (TCU) • Deposition nozzle produces highly collimated spray pattern • Area coverage using X-Y rastering of nozzle and/or rotation of substrate Deposition Nozzle Substrate

  5. KM–CDS First KM-CDS Shipped!! Buyer: US Naval Academy Located: NAVSEA-Carderock • Coating Development System • Desk sized • Production unit • Same footprint • Remove spray enclosure

  6. Application SSME Main Combustion Chamber (MCC) • MCC liner life in LOX/H2 engine limited by thermal ratcheting failure initiated by cyclic oxidation/ reduction (“blanching”) of copper alloy liner • Desire high conductivity coating that forms adherent, self healing oxide that is stable in H2 • Candidate coatings include Cu-xCr, where x = 20 to 30 vol.% • Study initiated to select optimum composition of Cu-XCr based on mechanical properties and oxidation resistance

  7. Advantages • KM vs. Thermal Spray • Eliminates: • Porosity • Oxygen pickup • Interlayer bond coats • Vacuum chamber

  8. Coating Properties KM Cu-Cr Deposit • Bulk Cu-Cr specimens machined from 10-mm thick KM deposits • Tensile • Thermal Conductivity • Three Cu-Cr compositions evaluated: • Cu-20vol.%Cr • Cu-25vol.%Cr • Cu-30vol.%Cr Copper Substrate Thermal Expansion Specimens Tensile Specimens Thermal Conductivity Specimens

  9. Tensile Properties • KM Cu-Cr tensile properties equivalent to wrought • Strength increases (ductility decreases) with increasing Cr content Wrought KM

  10. Fractography • Ductile, microvoid coalescence observed at room temperature

  11. Thermal Conductivity • KM Cu-Cr thermal conductivity equivalent to wrought • Conductivity decreases with increasing Cr content

  12. Oxidation Behavior • Evaluation of KM Cu-Cr coated GRCop-84 TGA coupons included: • Coating Adhesion • Static Oxidation • Cyclic Oxidation • Three Cu-Cr compositions evaluated: • Cu-20vol.%Cr • Cu-25vol.%Cr • Cu-30vol.%Cr KM Cu-Cr Coated GRCop-84 TGA Coupons KM Cu-25vol.%Cr GRCop-84

  13. Note: Arrows indicate failure in epoxy Coating Adhesion • Coating adhesion improved by post-deposition heat treatment

  14. Static Oxidation • Formation of continuous Cr2O3 layer underneath external CuO slows oxidation rate • Oxidation rate decreases with increasing Cr content CuO Cr2O3 20Cr Cu-Cr coating 25Cr

  15. Cu-25vol.%Cr 25.0 Cr Cu-20vol.%Cr 20.0 Cr 650ºC 750ºC Cyclic Oxidation • Cyclic Temperature 77 ºK to 1023 ºK • Best oxidation resistance Cu-Cr Coating with 25vol% Cr • Spalling observed

  16. Summary • Kinetic Metallization achieves high density, adherent Cu-Cr coatings • Eliminates need for interlayer bond coat • Eliminates oxygen pickup during spray process • Best balance of oxidation protection and mechanical properties offered by Cu-25vol.%Cr

  17. Future Work • NASA initiated new program to evaluate KM NiCrAlY coatings for next-generation LOX/kerosene engines • Preliminary work has shown that low porosity, well-adherent KM NiCrAlY coatings can be applied to GRCop-84 • No grit blasting surface preparation required • No interlayer bond coat required KM NiCrAlY

More Related