Tooling system for superplastic forming of metals

Claim 2

A tooling system for superplastic forming of a workpiece, comprising: a shell, said shell comprising an upper subshell and a lower subshell; an upper die member disposed within said upper subshell, said upper die member composed of liquid hardenable material; a lower die member disposed within said lower subshell, said lower member composed of liquid hardenable material, said upper member having a surface exposed from said upper subshell and said lower member having a surface exposed from said lower subshell, said upper member surface and said lower member surface defining a die cavity when said upper member and said lower member are joined together; means for releasably securing said upper subshell and said lower subshell together; p1 means for heating the die cavity; a source of pressurized gas; a gas conduit, said gas conduit connecting said source of gas to the cavity for providing pressurized gas to the workpiece in the cavity in order to superplastically form the workpiece; a resiliant venting means associated with said securing means for relieving excessive gas pressure within the cavity.

Claim 3

The system of claim 1 wherein said venting means includes springs mounted on said shell, said springs exerting a force tending to close said upper and said lower subshells together, said springs having a tension allowing gas pressure in the cavity to automatically separate said upper subshell from said lower subshell when the gas pressure in the cavity exceeds a desired value.

Claim 4

The system of claim 1 wherein said liquid hardenable material is ceramic.

Claim 5

The system of claim 1 further including a thermo-couple connected to said means for heating.

Claim 6

The system of claim 1 wherein said means for heating comprises an upper heating element within said upper member and a lower heating element within said lower member.

Claim 7

The system of claim 5 wherein said upper heating element and said lower heating element are spaced between one eighth and one quarter of an inch from the cavity.

Claim 8

The system of claim 1 wherein said shell has an oblate spheroid shape when said upper subshell and said lower subshell are secured together.

Claim 9

The system of claim 1 wherein said means for releasably securing is at least one fastener.

Claim 10

The system of claim 8 wherein at least one fastener comprises a plurality of fasteners positioned at junctures of said upper subshell and said lower subshell.

Claim 11

A tooling system for superplastic forming of a workpiece capable of superplastic deformation, comprising: a die, said die comprising an upper die member and a lower die member, said upper die member having a surface which is mateable with a surface of said lower die member so that said upper die member can be joined to said lower die member, said upper die member having a surface portion and said lower die member having a surface portion, said portion of said upper member in conjunction with said portion of said lower member defining a die cavity for superplastic forming of a workpiece therein: a shell, said shell comprising an upper shell member partially enclosing said upper die member and a lower shell member partially enclosing said lower die member; a heating element, said heating element embedded in said die for heating the workpiece; an electrical power supply connected to said heating element; a supply of pressurized gas; a gas tube connecting said supply of gas to the cavity, said gas tube mounted within said die member; a plurality of clamps for securing said upper and said lower shells members together at their peripheral edges in order to enclose said die; a supply of quenching fluid; means for providing fluid from said supply of fluid to the cavity in order to quench the workpiece formed therein; at least one spring mounted between an end of at least one of said plurality of clamps and peripheral portions of said upper and said lower subshells, said at least one spring having a tension strength allowing said upper shell to separate from said lower shell when the gas pressure in the cavity exceeds a desired value in order to release gas under pressure therefrom to provide automatic venting of excessive gas pressure within the cavity.

Claim 12

A tooling system for superplastic forming of a workpiece capable of superplastic deformation, comprising: a die, said die comprising an upper die member and a lower die member, said upper die member having a surface which is mateable with a surface of said lower die member so that said upper die member can be joined to said lower die member, said upper die member having a surface portion and said lower die member having a surface portion, said portion of said upper member in conjunction with said portion of said lower member defining a die cavity for superplastic forming of a workpiece therein: a shell, said shell comprising an upper shell member partially enclosing said upper die member and a lower shell member partially enclosing said lower die member; a heating element, said heating element embedded in said die for heating the workpiece; an electrical power supply connected to said heating element; a supply of pressurized gas; a gas tube connecting said supply of gas to the cavity, said gas tube mounted within said die member; a plurality of clamps for securing said upper and said lower shells members together at their peripheral edges in order to enclose said die; a supply of quenching fluid; means for providing fluid from said supply of fluid to the cavity in order to quench the workpiece formed therein; at least one spring mounted between an end of at least one of said plurality of clamps and peripheral portions of said upper and said lower subshells, said at least one spring having a tension strength allowing said upper shell to separate from said lower shell when the gas pressure in the cavity exceeds a desired value in order to release gas under pressure therefrom to provide automatic venting of excessive gas pressure within the cavity.

Claim 13

The system of claim 10 wherein said shell has an oblate spheroid shape when said upper shell member and said lower shell member are joined together.

Claim 14

The system of claim 10 wherein the workpiece has a border for sealing the cavity in order to prevent gas from escaping therefrom.

Claim 15

The system of claim 10 wherein said heating element is spaced between one eighth of an inch and one quarter of an inch from the cavity.

Claim 16

The system of claim 10 further including a thermo-couple connected to said heating element for monitoring the temperature thereof.

Claim 17

The system of claim 10 wherein said upper die member is composed of liquid hardenable ceramic material.

Claim 18

The system of claim 15 wherein said liquid hardenable material has high compressive strength and low thermal conductivity relative to the workpiece.

Claim 19

The system of claim 10 wherein said lower die member is composed of liquid hardenable ceramic material.

Claim 20

The system of claim 17 wherein said liquid hardenable material has high compressive strength and low thermal conductivity relative to the workpiece.

Claim 21

A tooling system for superplastic forming of a metal workpiece comprising: an upper die member, said upper die member composed of liquid hardenable ceramic material; a lower die member, said lower die member composed of liquid hardenable ceramic material, said upper die member having a face and said lower die member having a face, said members being joinable at said faces, said upper die member face having a recessed portion and said lower die member face having a recessed portion, said upper face portion and said lower face portion defining a cavity therebetween for superplastic forming of the workpiece, at least one of said portions of said upper and said lower die member faces having a die surface; an upper shell member, said upper shell member containing said upper die member, said upper shell member having a peripheral portion; a lower shell member, said lower shell member containing said lower die member, said lower shell member having a peripheral portion mateable with said peripheral portion of said upper die member so that said upper shell member may be joined to said lower shell member at said peripheral portions of said upper member and at said peripheral portion of said lower member in order that said upper shell member and said lower shell member form an oblate spheroid shell; a clamp mounted at said peripheral portion of said upper shell member and at said peripheral portion of said lower shell member for releasably securing said upper shell member and said lower shell member together in order to contain gas under pressure therein, said clamp being spring loaded for automatic venting of excessive gas pressure from the cavity. an upper heating element mounted within said upper die member, said upper heating element positioned between one eighth of an inch and one quarter of an inch from the cavity; a lower heating element mounted within said lower die member, said lower heating element positioned between one eighth of an inch and one quarter of an inch from the cavity; a pressurized gas supply; a gas conduit connecting said gas supply to at least one of said portions of said upper and lower die member faces for providing gas under pressure to the cavity; a quenching fluid supply; a quenching fluid conduit connecting said quenching fluid supply to at least one of said portions of said upper and said lower die member faces for providing quenching fluid to the workpiece in the cavity; a thermo-couple connected to said upper heating element and said lower heating elements for monitoring the temperature of said upper and said lower heating elements; an electrical power supply connected to said upper heating element and said lower heating element for supplying electrical power thereto.

Claim 22

A tooling system for superplastic forming of a metal workpiece comprising: an upper die member, said upper die member composed of liquid hardenable ceramic material; a lower die member, said lower die member composed of liquid hardenable ceramic material, said upper die member having a face and said lower die member having a face, said members being joinable at said faces, said upper die member face having a recessed portion and said lower die member face having a recessed portion, said upper face portion and said lower face portion defining a cavity therebetween for superplastic forming of the workpiece, at least one of said portions of said upper and said lower die member faces having a die surface; an upper shell member, said upper shell member containing said upper die member, said upper shell member having a peripheral portion; a lower shell member, said lower shell member containing said lower die member, said lower shell member having a peripheral portion mateable with said peripheral portion of said upper die member so that said upper shell member may be joined to said lower shell member at said peripheral portions of said upper member and at said peripheral portion of said lower member in order that said upper shell member and said lower shell member form an oblate spheroid shell; a clamp mounted at said peripheral portion of said upper shell member and at said peripheral portion of said lower shell member for releasably securing said upper shell member and said lower shell member together in order to contain gas under pressure therein, said clamp being spring loaded for automatic venting of excessive gas pressure from the cavity. an upper heating element mounted within said upper die member, said upper heating element positioned between one eighth of an inch and one quarter of an inch from the cavity; a lower heating element mounted within said lower die member, said lower heating element positioned between one eighth of an inch and one quarter of an inch from the cavity; a pressurized gas supply; a gas conduit connecting said gas supply to at least one of said portions of said upper and lower die member faces for providing gas under pressure to the cavity; a quenching fluid supply; a quenching fluid conduit connecting said quenching fluid supply to at least one of said portions of said upper and said lower die member faces for providing quenching fluid to the workpiece in the cavity; a thermo-couple connected to said upper heating element and said lower heating elements for monitoring the temperature of said upper and said lower heating elements; an electrical power supply connected to said upper heating element and said lower heating element for supplying electrical power thereto.

Claim 23

The system of claim 19 wherein said liquid hardenable material in said upper die member is liquid hardened with an upper duct for receiving said upper heating element and said liquid hardenable material in said lower die member is liquid hardened with a lower duct for receiving said lower heating element.