Reaction bonded carbide, nitride, boride, silicide or sulfide bodies

Claim 1

A method of joining solid carbide, boride, nitride, silicide or sulfide bodies, comprising the steps of: (a) providing a first solid body consisting essentially of: (i) 5 to 100 mole % of first phase or phases selected from the group consisting of: a boride, carbide, nitride, silicide or sulfide, or combinations thereof, of elements in groups 2a, 3a, 4a, 2b, 3b (including the lanthanide and actinide series), 4b, 5b, 6b, 7b and 8; and (ii) 0-95 mole % of second phase or phases of metal, intermetallic compound, alloy, or oxide, or combinations thereof; (b) providing a second solid body consisting essentially of material with phase or phases selected from the group consisting of: boride, oxide, carbide, nitride, silicide, or sulfide, or combinations thereof, of elements in groups 2a, 3a, 4a, 2b, 3b (including the lanthanide and actinide series), 4b, 5b, 6b, 7b and 8; a metal; an alloy; an intermetallic compound; or carbon; or combinations thereof; (c) providing an intermixture of precursors capable of reacting exothermically, said precursors being selected to yield an exothermic reaction product comprising at least 5 to 100 mole % of a first reaction product phase or phases of boride, carbide, nitride, silicide, sulfide or combinations thereof, of elements of groups 2a, 3a, 4a, 2b, 3b (including the lanthanide and actinide series), 4b, 5b, 6b, 7b and 8, and 0-95 mole percent of a second reaction product phase or phases of metal, intermetallic compound, alloy, oxide or combinations thereof; (d) laminating said mixture of precursors between portions of said solid bodies to be joined to form an intermediate laminate; and (e) heating said laminate in the absence of atmospheric reactants to a heat sufficient to initiate an exothermic reaction which joins said solid bodies.

Claim 2

A method of joining solid carbide, boride, nitride, silicide or sulfide bodies, comprising the steps of: (a) providing a first solid body consisting essentially of: (i) 5 to 100 mole % of first phase or phases selected from the group consisting of: a boride, carbide, nitride, silicide or sulfide, or combinations thereof, of elements in groups 2a, 3a, 4a, 2b, 3b (including the lanthanide and actinide series), 4b, 5b, 6b, 7b and 8; and (ii) 0-95 mole % of second phase or phases of metal, intermetallic compound, alloy, or oxide, or combinations thereof; (b) providing a second solid body consisting essentially of material with phase or phases selected from the group consisting of: boride, oxide, carbide, nitride, silicide, or sulfide, or combinations thereof, of elements in groups 2a, 3a, 4a, 2b, 3b (including the lanthanide and actinide series), 4b, 5b, 6b, 7b and 8; a metal; an alloy; an intermetallic compound; or carbon; or combinations thereof; (c) providing an intermixture of precursors capable of reacting exothermically, said precursors being selected to yield an exothermic reaction product comprising at least 5 to 100 mole % of a first reaction product phase or phases of boride, carbide, nitride, silicide, sulfide or combinations thereof, of elements of groups 2a, 3a, 4a, 2b, 3b (including the lanthanide and actinide series), 4b, 5b, 6b, 7b and 8, and 0-95 mole percent of a second reaction product phase or phases of metal, intermetallic compound, alloy, oxide or combinations thereof; (d) laminating said mixture of precursors between portions of said solid bodies to be joined to form an intermediate laminate; and (e) heating said laminate in the absence of atmospheric reactants to a heat sufficient to initiate an exothermic reaction which joins said solid bodies.

Claim 5

A method as claimed in any of claims 1 to 3 characterised in that step (d) comprises forming a joining layer of said mixture between opposing surfaces of said bodies.

Claim 6

A method as claimed in any of claims 1 to 4 characterised in that said opposing surfaces are cleaned prior to performing step (d).

Claim 7

A method as claimed in any of claims 1 to 5 characterised in that the laminating step comprises pressing said precursors between said bodies at pressures of at least 35 kg/cm 2 , preferably at least 140 kg/cm 2 and in particular approximately 420 kg/cm 2 .

Claim 8

A method as claimed in any of claims 1 to 6 characterised in that step (a) comprises providing a first solid body consisting essentially of a TiB 2/ Al composite.

Claim 9

A method as claimed in any of claims 1 to 6 characterised in that said precursors are selected to yield an exothermic reaction sintered joint consisting essentially of: (a) 30-95 mole % of at least a boride, carbide, nitride, silicide, sulfide or a combination therof of one or more of elements of groups 2a, 3a exclusive of B, 4a, 2b, 3b, including lanthanide and actinide series elements, 4b, 5b, 6b, 7b and 8, and (b) 5-70 mole % of a second phase(s) of metal, alloy, intermetallic compound, or combination thereof, of one or more of the elements of groups 3a exclusive of B, 4a, lb, 2b, 4b, 5b, 6b, 7b and 8; and (c) said joint containing less than about 4 weight % oxygen.

Claim 10

A method as claimed in any of claims 1 to 6 characterised in that said precursors are selected to yield exothermic reaction sintered joint consisting essentially of: (a) 10-90 mole % of boride phase or phases, being boride of one or more of the elements of groups 3b including lanthanide and actinide series elements, 4b, 5b and 6b, and (b) 10-90 mole % of oxide phase or phases, being oxide of one or more of the elements of groups 3a, 4a, 3b, 4b, 5b, 6b and 8.

Claim 11

A method as claimed in any of claims 1 to 6 characterised in that the precursors are selected to yield an exothermic reaction sintered joint consisting essentially of: (a) 5-95 mole % of nitride phase or phases, being nitride of one or both of Al and Si, and (b) 5-95 mole % of a second phase or phases, being boride, carbide, silicide, sulfide, or a combination thereof, of one or more of the elements of groups 3b, including lanthanide and actinide series elements, 4b, 5b and 6b; and (c) said joint containing less than about 4 weight % oxygen.

Claim 12

A method as claimed in any of claims 1 to 6 characterised in that step (a) comprises providing a polycrystalline TiB 2 first body, step (b) comprises providing a polycrystalline alpha alumina second body, and step (c) comprises providing a precursor mixture of boride, carbide, nitride, or silicide of Ti or Al, or mixtures thereof.

Claim 14

A method as claimed in any of claims 1 to 6 characterised in that said first and second bodies are selected to consist of essentially the same phase or phases.

Claim 15

A method as claimed in any of claims 1 to 6 characterised in that the exothermic reaction product is selected to consist of essentially the same phase or phases as one of said bodies.

Claim 17

A method as claimed in any of claims 1 to 6 characterised in that step (a) comprises providing a polycrystalline TiB 2 first body, step (b) comprises providing a metallic second body, and step (c) comprises providing a precursor mixture of boride, carbide, nitride or silicide of Ti, Al, Ni, or Fe, or mixtures thereof.

Claim 19

A method as claimed in any of claims 1 to 6 characterised in that step (c) comprises providing precursors selected from the group consisting of: hydride and boride of Ti, Ni, Fe or Al, or mixtures thereof.

Claim 20

A method as claimed in any of claims 1 to 6 characterised in that step (a) comprises providing a polycrystalline TiB 2 first body, step (b) comprises providing a silicon nitride second body, and step (c) comprises providing a precursor mixture of silicide, .boride, nitride, carbide or hydride of Ti, Si, or B or mixtures thereof.