# US 2013/0156626 A1 · Method for manufacturing a part by metal injection moulding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156626 A1 - Document ID: US20130156626A1 - Status: Published application - Kind: A1 - Application number: 13/720,577 - Filed: 2012-12-19 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Rolls-Royce Deutschland Ltd & Co KG - Inventors: Dan ROTH-FAGARASEANU; Lukas SCHRUEFER - Web page: https://patentgrep.com/patent/US20130156626A1 ## CPC - B22F 7/02: of composite layers {(B22F7/002 takes precedence)} - B22F 3/225: {by injection molding} - B22F 5/009: {of turbine components other than turbine blades (of turbine blades B22F5/04)} - B22F 5/04: of turbine blades - B22F 7/06: of composite workpieces or articles from parts, e.g. to form tipped tools {(B22F7/002 takes precedence)} - B22F 7/062: {involving the connection or repairing of preformed parts} - B22F 2005/005: {Article surface comprising protrusions} - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER ## Abstract A method for manufacturing a part includes metal injection molding of metal powder mixed with a binder to produce individual components of the part as separately molded green compact sections which are then debindered to form brown compact sections. At least one of the brown compact sections is subjected to a pre-sintering process to undergo a first shrinkage. The pre-sintered brown compact section and a further brown compact section are joined together to form a multi-part brown compact which is subsequently subjected to a main sintering process, where the pre-sintered brown compact section undergoes less shrinkage than the further brown compact section to draw together and firmly connect the pre-sintered brown compact section and the further brown compact section. ## Claims ### Claim 1 A method for manufacturing a part, comprising: producing individual components of the part as separately molded green compact sections by metal injection molding of metal powder mixed with a binder, and then removing the binder from the green compact sections to form debindered brown compact sections; subjecting at least one of the brown compact sections to a pre-sintering process in which it undergoes a first shrinkage; connecting together the at least one pre-sintered brown compact section and at least one further brown compact section to form a multi-part brown compact; and subsequently subjecting the multi-part brown compact to a main sintering process whereby the connected brown compact sections undergo shrinkage, with the at least one pre-sintered brown compact section undergoing a second shrinkage less than a shrinkage of the at least one further brown compact section to draw together and firmly connect to one another the at least one pre-sintered brown compact section and the at least one further brown compact section. ### Claim 2 (depends on 1) The method in accordance with claim 1, wherein the pre-sintered brown compact section and the further brown compact section are connected to one another before the main sintering process by positively engaging connecting elements provided on joining surfaces of the brown compact sections to be connected. ### Claim 3 (depends on 2) The method in accordance with claim 2, and further comprising providing the brown compact section to be pre-sintered with dimensions such that, before being subjected to the pre-sintering process, it cannot be connected to the further brown compact section, and during the pre-sintering process shrinks sufficiently such that it can be connected to the two further brown compact section. ### Claim 4 (depends on 2) The method in accordance with claim 2, and further comprising providing the connecting elements of the brown compact sections as positively engaging projections and recesses, with the projections tapering towards the contact surface between the brown compact sections having at least one chosen from a dovetail and a club shape, and the recesses having a matching and complementary shape. ### Claim 5 (depends on 4) The method in accordance with claim 4, and further comprising providing the projections the brown compact section which is pre-sintered, and the recesses on the further brown compact section. ### Claim 6 (depends on 4) The method in accordance with claim 4, and further comprising providing the recesses the brown compact section which is pre-sintered, and the projections on the further brown compact section. ### Claim 7 (depends on 4) The method in accordance with claim 4, and further comprising providing the projections with a convex curvature and the recesses with a concave curvature. ### Claim 8 (depends on 1) The method in accordance with claim 1, and further comprising: connecting together at least three brown compact sections and jointly sintering the connected at least three brown compact sections in the main sintering process, and providing that one of the at least three brown compact sections is a connecting part with two connecting elements such that it can be joined together with two further brown compact sections before the main sintering process; pre-sintering either the brown compact section which is the connecting part or the two further brown compact sections; and then connecting to one another the two further brown compact sections using the brown compact section which is the connecting part for the main sintering process. ### Claim 9 (depends on 8) The method in accordance with claim 8, and further comprising providing the brown compact section which is the connecting part with two projections acting as connecting elements. ### Claim 10 (depends on 8) The method in accordance with claim 8, wherein the brown compact section which is the connecting part draws the two other brown compact sections against one another during the main sintering process. ### Claim 11 (depends on 1) The method in accordance with claim 1, and further comprising providing a part of rotationally symmetrical design where the connected brown compact includes an inner brown compact section and an outer brown compact section enclosing the inner brown compact section, optionally providing connecting elements to connect the inner and outer brown compact sections, providing that the inner brown compact section is the pre-sintered brown compact section and, via the main sintering process of the connected brown compact, causing the outer brown compact section to press against the inner brown compact section. ### Claim 12 (depends on 1) The method in accordance with claim 1, wherein the at least one pre-sintered brown compact section and the further brown compact sections consist of a same material and have substantially identical shrinkage properties. ### Claim 13 (depends on 1) The method in accordance with claim 1, wherein the at least one pre-sintered brown compact section undergoes a volume shrinkage of at least 2% during pre-sintering. ### Claim 14 A method for manufacturing a part, comprising: producing separately molded green compact sections by metal injection molding of metal powder mixed with a binder, and then removing the binder from the green compact sections to form debindered brown compact sections; connecting together at least three brown compact sections and then jointly sintering the connected at least three brown compact sections in a sintering process; providing that one of the at least three brown compact sections being connected together is a connecting part that is connected with at least two further brown compact sections before the sintering process, the connecting part undergoing different shrinkage than the at least two further brown compact sections during the sintering process so that the at least two further brown compact sections and the connecting part are drawn together during the sintering process to be firmly connected to one another via the connecting part. ### Claim 15 (depends on 14) The method in accordance with claim 14, wherein the connecting part and the further brown compact sections consist of a same material and have substantially identical shrinkage properties, and further comprising subjecting either the connecting part or the further brown compact sections to a pre-sintering process in which pre-shrinkage takes place before the sintering process. ### Claim 16 (depends on 14) The method in accordance with claim 14, and further comprising providing the connecting part with different shrinkage properties as compared with the further brown compact sections. ### Claim 17 (depends on 16) The method in accordance with claim 16, and further comprising providing the different shrinkage properties due to differences in at least one chosen from a type of metal powder particles, a size of the metal powder particles, a material of the metal powder particles and a binder used to bind the metal powder particles.