# US 9,517,535 B2 · Method for repairing a piece > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,535 B2 - Document ID: US9517535B2 - Status: Granted - Kind: B2 - Application number: 13/921,553 - Filed: 2013-06-19 - Published: 2013-12-19 - Granted: 2016-12-13 - Earliest claimed: 2012-06-19 - Assignees: GE Avio S.r.l. - Applicants: AVIO S.p.A. - Inventors: Giovanni Paolo Zanon; Agostino Scialpi - Web page: https://patentgrep.com/patent/US9517535B2 ## CPC - B23P 6/00: Restoring or reconditioning objects (straightening or restoring form of sheet metal, metal rods, metal tubes, metal profiles, or specific articles made therefrom B21D1/00, B21D3/00; repairing defective or damaged objects by casting techniques B22D19/10) - C23C 26/00: Coating not provided for in groups C23C2/00 - C23C24/00 - Y10T 29/49746: by applying fluent material, e.g., coating, casting - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A material is deposited on the surface of a piece to be repaired, by means of two steps of electro-spark deposition alternated with an intermediate compaction step, which reduces the surface asperity of a layer of material deposited before another material is deposited; the compaction phase is defined by shot peening, performed by means of shots supported by at least one flexible element supported projecting from a rotating shaft. ## Claims ### Claim 1 A method for repairing a piece, comprising the steps of: performing a first electro-spark deposition step so as to form a first layer of material on a surface to be repaired forming part of said piece; performing at least a second electro-spark deposition step so as to form a second layer of material on said first layer; performing an intermediate compaction step between said first and said at least second electro-spark deposition steps, so as to reduce surface asperities of the first layer of material before initiating the second deposition step; wherein said compaction step comprises the step of shot peening, performed by a plurality of shots supported by at least one flexible element, which extends radially with respect to an axis and the additional step of rotating the at least one flexible element about said axis thereby impacting the plurality of shots against the layer being compacted. ### Claim 2 (depends on 1) The method according to claim 1, wherein the deposited material is the same as the original material of the surface to be repaired. ### Claim 3 (depends on 1) The method according to claim 1, comprising further shot peening after said second electro-spark deposition step, in order to reduce surface asperities of the second layer of material. ### Claim 4 (depends on 1) The method according to claim 1, wherein said axis, during shot peening, is maintained in a position substantially parallel to the shot peened surface. ### Claim 5 (depends on 1) The method according to claim 1, further including a step of assessing the compaction quality as a function of shot peening intensity, by way of preliminary experimental tests; said shot peening being carried out with parameters to obtain a shot peening intensity corresponding to a desired level of compaction quality. ### Claim 6 (depends on 1) The method according to claim 1, wherein the step of shot peening is performed at a rotation rate of about 5000 rpm. ### Claim 7 A method for repairing a piece comprising the steps of: depositing by electro-spark deposition a first layer of material on a surface of a piece being repaired; depositing by electro-spark deposition a material so as to form a second layer of material on the first layer of material; performing an intermediate compaction step between the first and second material deposition steps so as to reduce surface asperities of the first layer of material before the second deposition step by rotating a plurality of confined shots against the deposited layer thereby permitting the depositing of a higher volume of material; and performing in an alternating manner the depositing by electro-spark deposition additional layers of material and the compacting of each of the additionally deposited layers of material to reduce surface asperities in each subsequently deposited layer prior to the next layer being deposited until a chosen deposited material thickness is achieved. ### Claim 8 (depends on 7) The method for repairing a piece as in claim 7 wherein the step of compacting surface asperities comprises shot peening using a plurality of shots on at least one flexible element. ### Claim 9 (depends on 8) The method for repairing a piece as in claim 8 wherein the at least one flexible element comprises a flexible tab. ### Claim 10 (depends on 8) The method for repairing a piece as in claim 8 wherein the at least one flexible element comprises flexible strands. ### Claim 11 (depends on 10) The method for repairing a piece as in claim 10 wherein the flexible strands comprise wires. ### Claim 12 (depends on 10) The method for repairing a piece as in claim 10 wherein the flexible strands comprise bristles. ### Claim 13 (depends on 7) The method for repairing a piece as in claim 7 wherein the material for both the first and second deposition steps is the same. ### Claim 14 (depends on 7) The method for repairing a piece as in claim 7 including the further step of machining the deposited material to obtain a desired material dimension. ### Claim 15 (depends on 7) The method according to claim 7, wherein the step of shot peening is performed by a device rotating at 5000 rpm and for a time of about 2 minutes.