Claims
- 1. A method of manufacture of a product having increased resistance to creep and crack propagation from prealloyed powder of a nickel-based superalloy, said method comprising the steps of:
- (a) preparing a prealloyed powder of a nickel-based superalloy, particles of said powder having a size limited by screening, and having segregated elements on their surface;
- (b) subjecting said powder to a preheat treatment of internally precipitating said segregated elements in stable phases inside said particles of powder, said preheat treatment being carried out under low pressure or without pressure and at a temperature below an incipient melting point of said superalloy;
- (c) subjecting said powder to a consolidation treatment by hot compaction under high pressure for manufacturing said product; and
- (d) subjecting said product to a stage of enlarging the sizes of metallurgical grain of the alloy beyond the boundaries of the powder particles by heating at a temperature above the solvus temperature of the alloy.
- 2. A method of manufacture of a product having increased resistance to creep and crack propagation from prealloyed powder of a nickel-based superalloy, said method comprising the steps of:
- (a) preparing a prealloyed powder of a nickel-based superalloy, particles of said powder having a size limited by screening, and having segregated elements on their surface;
- (b) subjecting said powder to a preheat treatment of internally precipitating said segregated elements in stable phases inside said particles of powder, said preheat treatment being carried out under low pressure or without pressure and at a temperature below an incipient melting point of said superalloy;
- (c) subjecting said powder to a consolidation treatment by hot compaction under high pressure for manufacturing said product;
- (d) said hot compaction treatment comprising a stage of enlarging the sizes of metallurgical grain of said superalloy beyond boundaries of said particles by heating under high pressure at a temperature above a solvus temperature of said superalloy.
- 3. A method according to claim 1 or 2, wherein said preheat treatment is carried out under low pressure not exceeding 1 atm.
- 4. A method according to claim 1 or 2 , wherein said preheat treatment is carried out at a temperature between about 100.degree. C. below said solvus temperature and said incipient melting point of said superalloy.
- 5. A method according to claim 4, wherein said preheat treatment is carried out at a temperature above said solvus temperature.
- 6. A method according to claim 1 or 2, wherein said stage of enlarging the metallurgical grains is performed under a pressure of about 100 MPa.
- 7. A method according to claim 1 or 2, wherein said consolidation treatment is carried out by hot isostatic pressing.
- 8. A method according to claim 7, wherein said consolidation treatment includes a stage of low pressure compaction and a subsequent hot isostatic pressure under high pressure.
- 9. A method according to claim 8, wherein at least one of said stages of compaction is carried out at a temperature above said solvus temperature of said superalloy.
- 10. A method according to claim 1 or 2, wherein the consolidation treatment is performed by extrusion.
Priority Claims (1)
Number |
Date |
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Kind |
90 00454 |
Jan 1990 |
FRX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/641,777 filed Jan. 16, 1991, now abandoned
US Referenced Citations (2)
Continuations (1)
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Number |
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Parent |
641777 |
Jan 1991 |
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