Applications - APS coatings - Applications of APS coatings Typical spray materials Oxide ceramics: Cr 2 O 3, Al 2 O 3, Al 2 O 3 /TiO 2 Compounds: Ni/C G, AlSi/Polyester, [WC/Co(Cr), Cr 3 C 2 /NiCr] Metals: Mo, NiCrBSi, CoCrWC, CoCrMoSi, CuAl(Fe), CuNi(In) Aim for surfaces of components build of cheap base materials or base materials that fufill structural demands (strength, formability) in an optimal way Partially in combination with corrosion protection Partially in combination with special surface properties like high or low wettability by different media Abradable coatings for clearance control Coatings with tribological function 1
Printing machines Ink ductor rollers in offset printing machines High resistance against wear by pigments in ink Ink is easily both picked up and transferred after adequate coating finishing APS sprayed Cr 2 O 3 APS sprayed Ni5Al bond coat Terolab Services König & Bauer Coatings with tribological function Printing machines Anilox rollers in flexo printing machines APS sprayed high purity Cr 2 O 3 (laser engraved) High wear resistance of small webs, easy ink take-up and cleaning Only metal free coatings permit homogeneous laser engraving and therefore suitable quality König & Bauer Coatings with tribological function 2
Printing machines Anilox rollers SOT, Salzgitter Coatings with tribological function Cooking pans APS Al 2 O 3 layer as wear resistant support for anti-sticking coating layer compound Easy cleaning of light-weight cast aluminum alloy pans 3
Textile industries Grooved rollers, godets, templates for guidance of fibres APS Al 2 O 3 /TiO 2 Depending on the specific demands coating surfaces need to be smoothened by brushing, grinding and / or polishing to avoid fibre damage Terolab Services Seals Seal rings with high wear resistance and low friction APS Cr 2 O 3 Post-treatment by polishing Related applications: - pump shafts - protective bushings Terolab Services 4
Piston rings APS Mo/NiCrBSi and coatings including molybdenum carbide compete against Al 2 O 3 or diamond impregnated hard chromium or PVD coating solutions Piston rings APS Mo/NiCrBSi coating Microhardness: ~ 500 HV0.3 Coating porosity has tribologoical function because of storage of oil in lubricating pockets 5
Hydraulic pistons APS Cr 2 O 3 /TiO 2 on APS Ni5Al bond coat Suitable for off-shore applications after sealing Hunger Hydraulik Automotive in-line engines APS iron based coatings with Mo addition Iron oxides provide to some extent lubrication Coating porosity has tribologoical function becasuse of storage of oil in lubricating pockets Special production line at Volkswagen and prototype production for Formula 1 engines Chemnitz University of Technology Chemnitz University of Technology 6
Automotive in-line and V-engines PTWA and HVCW of plain steel wires Cooperation project with Daimler Chrysler, Ford, Gehring, General Motors and Porsche water blasted, coated, honed I, honed II coating substrate Doctor blades APS Al 2 O 3 /TiO 2 or Cr 2 O 3 coated blades improve lifetime compared to uncoated spring steel significantly 7
Turbine blade roots APS CuNiIn coatings for titanium compressor blade roots prevent adhesive wear Compressors (gas turbines) Abradable coatings greatly improve efficiency of axial flow compressors by minimizing air leaks APS Al 2 O 3 (more and more replaced by HVOF WC/Co) on the compressor rotor and APS or powder flame sprayed Ni/C G on the casing APS AlSi/Polyester coatings are alternative abradable coatings APS Al 2 O 3 for protection of labyrinth seal webs on rotors combined with soft counterbody surfaces APS Al 2 O 3 effectively limits titanium fire in gas turbines compressor section Clearance control 8
Gas turbine blades and vanes Hot gas corrosion protective MCrAlY (M := Ni,Co) coatings are the traditional major application of vacuum plasma spraying MCrAlY coatings form a protective alumina scale with excellent bond to the metallic base and yttria prevents grain growth and therefore detrimental effect on thermal shock resistance Institute of Materials Technology, Dortmund Hot gas corrosion protection Gas turbine blades and vanes APS YPSZ (partially stabilized zirconia, ZrO 2 /Y 2 O 3 ) thermal barrier coatings Combustion chambers with up to 4.5 m diameter and up to 3.5 t weight For aero engines aviation approval required Thermal insulation 9
Gas turbine blades and vanes APS ZrO 2 /Y 2 O 3 thermal barrier coatings on MCrAlY bond coats Institute of Materials Technology, Dortmund Thermal insulation Gas turbine blades and vanes APS ZrO 2 /Y 2 O 3 thermal barrier coatings on MCrAlY bond coats Improved life-time of turbine components due to lower thermal load of the core material Maximum component surface temperature: ~ 1250 C Despite intensive long-term research no improvement by alternative material solution achieved up to now Major problem: Sintering at service temperature results in decreased fracture toughness temperature thermal barrier coating bond coat substrate Thermal insulation 10
Electrical insulation APS Al 2 O 3 for electrical insulation α-phase is desired, because of high electrical resistance, but mostly γ-phase is produced during thermal spraying Moisture needs to be excluded in order to provide sufficient shielding effect of high-γ content Al 2 O 3 coatings dynamo components Electrical insulation Implants VPS cp Ti, Ti6Al4V and / or hydroxyapatite coated hip, knee and tooth implants Very high demands concerning coating purity Titanium (alloys) do not corrode in human tissue (biocompatible) and hydroxyapatite coatings can partially dissolve and provide bone growth during re-precipitation (bioactive) Terolab Services Biocompatible and -active coatings 11
Hardmagnetic NdFeB coatings VPS NdFeB to prevent oxidation which has detrimental effect on the magnetic properties Substrate temperature control needed for good magnetic properties Up to now only laboratory scale production Sensor and actuator coatings Hardmagnetic NdFeB coatings APS Al 2 O 3 -MgO (Spinell) or YPSZ coatings provide high oxygen ion diffusivity Current (produced by ion flux) at given temperature is a measure for oxygen content in exhaust gas Specific Bosch product replaced by alternative technology Lambda probe Sensor and actuator coatings 12
Target production for PVD processes (sputtering) Depending on the desired type of PVD coating and the size of targets different thermal spray processes can be applied For arc-pvd CrN coating production usually VPS of chromium is carried out, because chromium strongly oxidizes during spraying under atmospheric conditions VPS chromium sputter targets Institute of Materials Technology, Dortmund Material build-up Thank you for your attention! Thanks 13