PLATINUM GROUP SILICIDE MODIFIED ALUMINIDE COATING PROCESS AND PRODUCT

• Main Authors: LAVERY, PATRICK R, ROSE, BERNARD R
• Format: Patent
• Language: English; French
• Published: 08.03.2005
• Edition: 5
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

Process for producing novel coated nickel and/or cobalt superalloy bodies having increased resistance to oxidation, corrosion and thermal fatigue at high temperatures. The process comprises applying a thin layer of a platinum-group metal, siliciding and heating to an elevated temperature to diffuse and integrate the silicided platinum-group metal into the surface of the superalloy body. Then the superalloy body is exposed to a diffusion powder composition containing sources of aluminum or aluminum/chromium metals and heated in a hydrogen or inert gas atmosphere to an elevated temperature to codeposit and diffuse aluminum or aluminum and chromium into the silicided platinum-group metal-treated surface. Finally, the superalloy body is heated to its solvus temperature to form a ductile surface having an outer zone comprising a platinum-group metal aluminide, optionally ductilized by the solutioning therein of beta chromium. An inner stabilizing zone of silicon-rich phases is formed during said diffusion processes.