Making spray-formed articles using a polymeric mandrel

• Main Authors: LARRY VAN VAN REATHERFORD, OLUDELE OLUSEGUN POPOOLA
• Format: Patent
• Language: English
• Published: 21.02.2001
• Edition: 7
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; 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

Method of making valve seats by thermally spraying bulk material includes the steps of: (i) preparing a cylindrical polymeric mandrel 10 having an outside dimension not greater than the desired inside dimension of the desired insert, the mandrel having no means to provide for separation of the sprayed material from the mandrel, (ii) thermal spraying separate particles 28 of one or more types of steel or nickel alloys in the presence of a controlled oxidising medium under conditions that allow firstly, melting of the mandrel and its infiltration into the sprayed material and secondly to form a subsequent polymer free dense metallic bulk composite material (iii) after cooling, machining and cutting into discrete seat shapes for use in internal combustion engines. Successive layers of metal particles may be applied stop the initial layer and the mandrel.