# US 5,350,107 A · Iron aluminide alloy coatings and joints, and methods of forming > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,350,107 A - Document ID: US5350107A - Status: Granted - Kind: A - Filed: 1993-09-08 - Granted: 1994-09-27 - Earliest claimed: 1990-10-26 - Assignees: EG&G Idaho, Inc. - Inventors: Richard N. Wright; Julie K. Wright; Glenn A. Moore - Web page: https://patentgrep.com/patent/US5350107A ## CPC - B22F 3/23: involving a self-propagating high-temperature synthesis or reaction sintering step {(making cermets by reaction sintering C22C1/051)} - C22C 1/047: comprising intermetallic compounds {(C22C1/0441 takes precedence)} - B22F 2201/10: Inert gases - B22F 2201/20: Use of vacuum - 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 - C22C: ALLOYS (treatment of alloys C21D, C22F) ## Abstract A method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, includes the following steps: a) providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; b) after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; c) heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600.degree. C. to less than the melting point of the lower melting point body; d) applying pressure on the juxtaposed surfaces; and e) maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. The method can also effectively be used to coat a body with an iron aluminide coating. ## Claims ### Claim 1 A method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, the method comprising the following steps: providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600.degree. C. to less than the melting point of the lower melting point body; applying pressure on the juxtaposed surfaces; and maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. ### Claim 2 (depends on 1) The method of joining two bodies together of claim 1 wherein the applied pressure is from about 10 MPa to 200 MPa. ### Claim 3 (depends on 1) The method of joining two bodies together of claim 1 wherein the aluminum and iron metals are provided in a selected s stoichiometric ratio on the joint surface, the stoichiometric ratio being effective to produce an iron aluminide alloy joint predominantly comprising Fe.sub.3 Al. ### Claim 4 (depends on 1) The method of joining two bodies together of claim 1 wherein the aluminum and iron metals are provided in a selected s stoichiometric ratio on the joint surface, the stoichiometric ratio being effective to produce an iron aluminide alloy joint predominantly comprising FeAl. ### Claim 5 (depends on 1) The method of joining two bodies together of claim 1 wherein the aluminum metal and iron metal are provided on the joint surface in powder form. ### Claim 6 (depends on 1) The method of joining two bodies together of claim 1 wherein the aluminum metal and iron metal are provided on the joint surface in a form of separate metal foils. ### Claim 7 (depends on 1) The method of joining two bodies together of claim 1 wherein the aluminum metal and iron metal are provided on the joint surface in a form of a homogenous polymer bound sheet. ### Claim 8 (depends on 1) The method of joining two bodies together of claim 1 wherein the aluminum metal and iron metal are provided in elemental form. ### Claim 9 (depends on 1) The method of joining two bodies together of claim 1 wherein at least one of the bodies being joined predominately comprises an iron aluminide. ### Claim 10 (depends on 1) The method of joining two bodies together of claim 1 wherein each body being joined predominately comprises metal. ### Claim 11 (depends on 1) The method of joining two bodies together of claim 1 wherein one of the bodies being joined is a ceramic. ### Claim 12 (depends on 1) The method of joining two bodies together of claim 1 wherein each body being joined predominately comprises an iron aluminide. ### Claim 13 (depends on 1) The method of joining two bodies together of claim 1 wherein the bodies being joined constitute different materials and have different melting points. ### Claim 14 A method of joining two bodies together, at least one of the bodies being predominantly composed of metal, the two bodies each having a respective joint surface for joining with the joint surface of the other body, the two bodies having a respective melting point, the method comprising the following steps: providing aluminum metal and iron metal on at least one of the joint surfaces of the two bodies; after providing the aluminum metal and iron metal on the one joint surface, positioning the joint surfaces of the two bodies in juxtaposition against one another with the aluminum and iron positioned therebetween; heating the aluminum and iron on the juxtaposed bodies to a temperature from greater than or equal to 600.degree. C. to less than the melting point of the lower melting point body; and maintaining the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy joint which bonds the juxtaposed surfaces and correspondingly the two bodies together. ### Claim 15 (depends on 14) The method of joining two bodies together of claim 14 wherein the aluminum and iron metals are provided in a selected stoichiometric ratio on the joint surface, the stoichiometric ratio being effective to produce an iron aluminide alloy joint predominantly comprising Fe.sub.3 Al. ### Claim 16 (depends on 14) The method of joining two bodies together of claim 14 wherein the aluminum and iron metals are provided in a selected stoichiometric ratio on the joint surface, the stoichiometric ratio being effective to produce an iron aluminide alloy joint predominantly comprising FeAl. ### Claim 17 (depends on 14) The method of joining two bodies together of claim 14 wherein the aluminum metal and iron metal are provided in elemental form. ### Claim 18 (depends on 14) The method of joining two bodies together of claim 14 wherein at least one of the bodies being joined predominately comprises an iron aluminide. ### Claim 19 (depends on 14) The method of joining two bodies together of claim 14 wherein each body being joined predominately comprises metal. ### Claim 20 (depends on 14) The method of joining two bodies together of claim 14 wherein one of the bodies being joined comprises a ceramic. ### Claim 21 (depends on 14) The method of joining two bodies together of claim 14 where in each body being joined predominately comprises an iron aluminide. ### Claim 22 A method of alloy coating a body with an iron aluminide alloy, the body having a melting point, the method comprising the following steps: providing aluminum metal and iron metal on a surface of the body to be alloy coated; heating the aluminum and iron to a temperature from greater than or equal to 600.degree. C. to less than the melting point of the body; applying pressure on the aluminum and iron against the body surface; and maintaining the pressure and the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy which adheres to and coats the surface. ### Claim 23 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the applied pressure is from about 10 MPa to 200 MPa. ### Claim 24 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the aluminum and iron metals are provided in a selected stoichiometric ratio on the surface, the stoichiometric ratio being effective to produce an iron aluminide alloy coating predominantly comprising Fe.sub.3 Al. ### Claim 25 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the aluminum and iron metals are provided in a selected stoichiometric ratio on the surface, the stoichiometric ratio being effective to produce an iron aluminide alloy coating predominantly comprising FeAl. ### Claim 26 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the aluminum metal and iron metal are provided on the surface in powder form. ### Claim 27 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the aluminum metal and iron metal are provided on the surface in a form of separate metal foils. ### Claim 28 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the aluminum metal and iron metal are provided on the surface in a form of a homogenous polymer bound sheet. ### Claim 29 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the aluminum metal and iron metal are provided in elemental form. ### Claim 30 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the applied coating has a thickness of from about 1 micron to about 10,000 microns. ### Claim 31 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the body being coated is a metal body. ### Claim 32 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the body being coated is a ceramic body. ### Claim 33 (depends on 22) The method of alloy coating a body with an iron aluminide alloy of claim 22 wherein the body being coated is predominantly composed of an iron aluminide. ### Claim 34 A method of alloy coating a body with an iron aluminide alloy, the body having a melting point, the method comprising the following steps: providing aluminum metal and iron metal on a surface of the body to be alloy coated; heating the aluminum and iron to a temperature from greater than or equal to 600.degree. C. to less than the melting point of the body; and maintaining the temperature for a time period effective to form the aluminum and iron into an iron aluminide alloy which adheres to and coats the surface. ### Claim 35 (depends on 34) The method of alloy coating a body with an iron aluminide alloy of claim 34 wherein the aluminum and iron metals are provided in a selected stoichiometric ratio on the surface, the stoichiometric ratio being effective to produce an iron aluminide alloy coating predominantly comprising Fe.sub.3 Al. ### Claim 36 (depends on 34) The method of alloy coating a body with an iron aluminide alloy of claim 34 wherein the aluminum and iron metals are provided in a selected stoichiometric ratio on the surface, the stoichiometric ratio being effective to produce an iron aluminide alloy coating predominantly comprising FeAl. ### Claim 37 (depends on 34) The method of alloy coating a body with an iron aluminide alloy of claim 34 wherein the aluminum metal and iron metal are provided in elemental form. ### Claim 38 (depends on 34) The method of alloy coating a body with an iron aluminide alloy of claim 34 wherein the applied coating has a thickness of from about 1 micron to about 10,000 microns. ### Claim 39 (depends on 34) The method of alloy coating a body with an iron aluminide alloy of claim 34 wherein the body being coated is metal body. ### Claim 40 (depends on 34) The method of alloy coating a body with an iron aluminide alloy of claim 34 wherein the body being coated is ceramic body. ### Claim 41 (depends on 34) The method of alloy coating a body with an iron aluminide alloy of claim 34 wherein the body being coated is predominantly composed of an iron aluminide.