US3804677A - Working of alloys - Google Patents
Working of alloys Download PDFInfo
- Publication number
- US3804677A US3804677A US00303718A US30371872A US3804677A US 3804677 A US3804677 A US 3804677A US 00303718 A US00303718 A US 00303718A US 30371872 A US30371872 A US 30371872A US 3804677 A US3804677 A US 3804677A
- Authority
- US
- United States
- Prior art keywords
- sheet material
- annealing
- superplastic
- bending
- alloy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
Definitions
- ABSTRACT A process for working superplastic sheet material comprising shaping the superplastic alloy by pressure or vacuum forming annealing the sheet material before or after the pressure of vacuum forming, and bending at least a part of the shaped sheet at room temperature.
- rolled superplastic zinc/aluminium alloy sheet material is annealed at about 200 C for at least one hour, vacuum or pressure forming carried out at 200 C to 250 C after the annealing, and the shaped sheet allowed to cool to room temperature before bending.
- strain rate sensitivity is the exponential variable in the expression a KE'", wherein or represents stress in load per unit area, g represents strain rate in terms of length change per unit time, and K represents a constant which is termed the strain rate co-efficient.
- strain rate coefficient K is significant in determining the strength of the material and hence the amount of work which must be put in to achieve a given forming operation.
- the invention in one aspect consists in a process for working alloy sheet material which has been conditioned to exhibit superplasticity, comprising: shaping the superplastic alloy by pressure or vacuum forming; annealing the sheet material before or after the said pressure or vacuum forming; and bending at least a part of the shaped sheet at or near room or ambient temperature.
- Room or ambient temperature is to be understood to be about 20 C.
- the annealing is carried out before the vacuum or pressure forming operation.
- the annealing temperature is within the range 150 to 250 C, more preferably about 200 C.
- the annealing time is suitably l to 2 hours.
- rolled superplastic zinc- /aluminium alloy sheet material is annealed at about 200 C for at least 1 hour, vacuum or pressure forming carried out at 200 C to 250 C, and the shaped sheet allowed to cool to room temperature before bending.
- the invention in another aspect consists in a process for working an alloy sheet material comprising rendering the alloy superplastic (as hereinbefore described), shaping the superplastic alloy by pressure or vacuum forming, annealing the sheet material before or after the said pressure or vacuum forming, and bending at least a part of the shaped sheet at or near room or ambient temperature.
- Tables 1, 2 and 3 below show the results of bending strips of a zinc/aluminium alloy (containing 87% by weight of zinc, 22% aluminium, and 0.15% of copper as a ternary element) of dimensions 1% inches X 3% inches around different bend radii (in inches) for three different gauges of alloy sheet, i.e. 0.025 inches, 0.050 inches, and 0.075 inches gauge.
- the specimens were annealed for 1 hour at 200 C and 250 C and then bent cold around the specified radii. The results of the cold bend tests are shown in the Tables.
- a process for working alloy sheet material which has been conditioned to exhibit superplasticity comprising: taking the said alloy sheet material; causing the said sheet material to conform to a moulding surface to shape the alloy sheet material; annealing the sheet material after the said shaping; and bending at least a part of the shaped sheet at room temperature.
- a process as claimed in claim 1 wherein the annealing time is from 1 to 2 hours.
- a process for working alloy sheet material which has been conditioned to exhibit superplasticity comprising: taking the said alloy sheet material; annealing the said sheet material; causing the sheet material to conform to a moulding surface to shape the alloy sheet material after the said annealing; and bending at least a part of the shaped sheet at room temperature.
- a process as claimed in claim 5 wherein the annealing temperature is within the range 150 to 250 C.
- a process as claimed in claim 5 wherein the annealing time is from 1 to 2 hours.
- a process for working alloy sheet material which has been conditioned to exhibit superplasticity comprising: taking the said alloy sheet material; annealing the said sheet material at about 200 C for at least 1 hour; causing the said sheet material to conform to a moulding surface to shape the alloy sheet material after the said annealing, the said shaping being carried out at a temperature of from 200 to 250 C; allowing the shaped sheet to cool to room temperature; and bending at least a part of the shaped sheet at room temperature.
- a process as claimed in claim 9 wherein the material being worked is superplastic zinc/aluminium sheet material.
Landscapes
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Bending Of Plates, Rods, And Pipes (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
- Forging (AREA)
- Heat Treatment Of Nonferrous Metals Or Alloys (AREA)
- Laminated Bodies (AREA)
Abstract
A process for working superplastic sheet material comprising shaping the superplastic alloy by pressure or vacuum forming, annealing the sheet material before or after the pressure of vacuum forming, and bending at least a part of the shaped sheet at room temperature. In a preferred procedure rolled superplastic zinc/aluminium alloy sheet material is annealed at about 200* C for at least one hour, vacuum or pressure forming carried out at 200* C to 250* C after the annealing, and the shaped sheet allowed to cool to room temperature before bending.
Description
United States Patent [191 Swanson Apr. 16, 1974 WORKING OF ALLOYS [75] Inventor: Colin John Swanson, Bristol,
England [22] Filed: Nov. 6, 1972 [21] Appl. No.: 303,718
[30] A Foreign Application Priority Data Nov. 4, 1971 Great Britain 51322/71 [52] US. Cl l48/l1.5 R [51] Int. Cl. C22f 1/16 [58] Field of Search t. 148/! 1.5 R
[56] References Cited UNITED STATES PATENTS 3,420,717 l/l969 Fields, Jr. et al. 148/11.5 R
3,567,524 3/1971 Cook et al. 148/1 1.5 R
Primary ExaminerW. W. Stallard Attorney, Agent, or Firm-Holman & Stern [5 7] ABSTRACT A process for working superplastic sheet material comprising shaping the superplastic alloy by pressure or vacuum forming annealing the sheet material before or after the pressure of vacuum forming, and bending at least a part of the shaped sheet at room temperature. In a preferred procedure rolled superplastic zinc/aluminium alloy sheet material is annealed at about 200 C for at least one hour, vacuum or pressure forming carried out at 200 C to 250 C after the annealing, and the shaped sheet allowed to cool to room temperature before bending.
10 Claims, No Drawings WORKING or ALLOYS This invention relates to the working of alloys which can be conditioned to exhibit the phenomenon known as superplasticity, and in particular to the working of 5 superplastic zinc/aluminium alloys.
The term superplasticity asused in this specification relates to the condition in which alloys exhibit a substantial strain rate sensitivity. Strain rate sensitivity, denoted m, is the exponential variable in the expression a KE'", wherein or represents stress in load per unit area, g represents strain rate in terms of length change per unit time, and K represents a constant which is termed the strain rate co-efficient.
While the existence of a substantial strain rate sensitivity m determines the ultimate elongation to which an alloy may be subjected without fracture, the strain rate coefficient K is significant in determining the strength of the material and hence the amount of work which must be put in to achieve a given forming operation.
It is already known to condition a blank of alloy to exhibit su'perplasticity by means of a heat treatmentlquenching/working technique and to cause the blank thus conditioned to conform to the shape of a moulding surface by means of fluid pressure or vacuum. However, after this moulding operation the alloy may still require further working to produce a further shape feature, for example a flange may be required on the finished article and this may involve a bending operation on at least a part of the moulded shape.
It may be demonstrated that the desirable properties of superplastic alloys may be achieved only at the expense of a reduction in the capability of the material to withstand bending stresses without cracking.
Because superplastic alloys are characterized by their high degree of strain rate sensitivity it is clear that difficulties encountered during cold bending may be overcome by lowering the rate of such bending. While this expedient may be acceptable in limited instances it is unlikely to be acceptable in a commercial forming process. v
The invention in one aspect consists in a process for working alloy sheet material which has been conditioned to exhibit superplasticity, comprising: shaping the superplastic alloy by pressure or vacuum forming; annealing the sheet material before or after the said pressure or vacuum forming; and bending at least a part of the shaped sheet at or near room or ambient temperature. Room or ambient temperature is to be understood to be about 20 C.
Usually the annealing is carried out before the vacuum or pressure forming operation.
Preferably the annealing temperature is within the range 150 to 250 C, more preferably about 200 C.
The annealing time is suitably l to 2 hours.
In a preferred procedure rolled superplastic zinc- /aluminium alloy sheet material is annealed at about 200 C for at least 1 hour, vacuum or pressure forming carried out at 200 C to 250 C, and the shaped sheet allowed to cool to room temperature before bending.
The invention in another aspect consists in a process for working an alloy sheet material comprising rendering the alloy superplastic (as hereinbefore described), shaping the superplastic alloy by pressure or vacuum forming, annealing the sheet material before or after the said pressure or vacuum forming, and bending at least a part of the shaped sheet at or near room or ambient temperature.
The invention will be further described with reference to the following examples.
Tables 1, 2 and 3 below show the results of bending strips of a zinc/aluminium alloy (containing 87% by weight of zinc, 22% aluminium, and 0.15% of copper as a ternary element) of dimensions 1% inches X 3% inches around different bend radii (in inches) for three different gauges of alloy sheet, i.e. 0.025 inches, 0.050 inches, and 0.075 inches gauge. The specimens were annealed for 1 hour at 200 C and 250 C and then bent cold around the specified radii. The results of the cold bend tests are shown in the Tables.
The rating of the effect of bending is related to the following scale:
Rating Degree of Cracking Complete fracture Heavy cracking Moderate cracking Light cracking No cracks.
CQUIU-lv- Table 1 0.025 inch Gauge Sheet Bend As Rolled Y Radius (at room Anneal (Inches) temperature) Temperature (C) Table 2 0.050 inch Gauge Sheet Bend As Rolled Radius (at room Anneal (l nches) temperature) Temperature Table 3 0.075 inch Gauge Sheet Bend As Rolled Radius (at room Anneal (lnches) temperature) Temperature (C) Table 4 Effect of temperature Bend Radius As Rolled Annealing Temperature (inches) (at room 100 I50 200 250 temperature) .250 l l 8 9 9 .l25 l l 7 9 9 .080 l l l 6 8 .040 l l l 4 7 .020 l l l 4 7 0 l 1 l 4 7 It will be recognised that to some extent the improvement in cold bending which is achieved by prior annealing arises from grain growth in the superplastic alloy. Increasing grain growth detracts from the superplastic properties. However, annealing for one hour at 200 C is likely to have a negligible effect on such superplastic properties.
I claim:
1. A process for working alloy sheet material which has been conditioned to exhibit superplasticity, comprising: taking the said alloy sheet material; causing the said sheet material to conform to a moulding surface to shape the alloy sheet material; annealing the sheet material after the said shaping; and bending at least a part of the shaped sheet at room temperature.
2. A process as claimed in claim 1 wherein the annealing temperature is within the range to 250 C.
3. A process as claimed in claim 1 wherein the annealing time is from 1 to 2 hours.
4. A process as claimed in claim 1 wherein the material being worked is superplastic zinc/aluminium alloy sheet material.
5. A process for working alloy sheet material which has been conditioned to exhibit superplasticity, comprising: taking the said alloy sheet material; annealing the said sheet material; causing the sheet material to conform to a moulding surface to shape the alloy sheet material after the said annealing; and bending at least a part of the shaped sheet at room temperature.
6. A process as claimed in claim 5 wherein the annealing temperature is within the range 150 to 250 C.
7. A process as claimed in claim 5 wherein the annealing time is from 1 to 2 hours.
8. A process as claimed in claim 5 wherein the material being worked is superplastic zinc/aluminium alloy sheet material.
9. A process for working alloy sheet material which has been conditioned to exhibit superplasticity, comprising: taking the said alloy sheet material; annealing the said sheet material at about 200 C for at least 1 hour; causing the said sheet material to conform to a moulding surface to shape the alloy sheet material after the said annealing, the said shaping being carried out at a temperature of from 200 to 250 C; allowing the shaped sheet to cool to room temperature; and bending at least a part of the shaped sheet at room temperature.
10. A process as claimed in claim 9 wherein the material being worked is superplastic zinc/aluminium sheet material.
Claims (9)
- 2. A process as claimed in claim 1 wherein the annealing temperature is within the range 150* to 250* C.
- 3. A process as claimed in claim 1 wherein the annealing time is from 1 to 2 hours.
- 4. A process as claimed in claim 1 wherein the material being worked is superplastic zinc/aluminium alloy sheet material.
- 5. A process for working alloy sheet material which has been conditioned to exhibit superplasticity, comprising: taking the said alloy sheet material; annealing the said sheet material; causing the sheet material to conform to a moulding surface to shape the alloy sheet material after the said annealing; and bending at least a part of the shaped sheet at room temperature.
- 6. A process as claimed in claim 5 wherein the annealing temperature is within the range 150* to 250* C.
- 7. A process as claimed in claim 5 wherein the annealing time is from 1 to 2 hours.
- 8. A process as claimed in claim 5 wherein the material being worked is superplastic zinc/aluminium alloy sheet material.
- 9. A process for working alloy sheet material which has been conditioned to exhibit superplasticity, comprising: taking the said alloy sheet material; annealing the said sheet material at about 200* C for at least 1 hour; causing the said sheet material to conform to a moulding surface to shape the alloy sheet material after the said annealing, the said shaping being carried out at a temperature of from 200* to 250* C; allowing the shaped sheet to cool to room temperature; and bending at least a part of the shaped sheet at room temperature.
- 10. A process as claimed in claim 9 wherein the material being worked is superplastic zinc/aluminium sheet material.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5132271A GB1363257A (en) | 1971-11-04 | 1971-11-04 | Working of alloy sheet material |
Publications (1)
Publication Number | Publication Date |
---|---|
US3804677A true US3804677A (en) | 1974-04-16 |
Family
ID=10459539
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00303718A Expired - Lifetime US3804677A (en) | 1971-11-04 | 1972-11-06 | Working of alloys |
Country Status (5)
Country | Link |
---|---|
US (1) | US3804677A (en) |
JP (1) | JPS5146507B2 (en) |
AU (1) | AU4845472A (en) |
FR (1) | FR2158536B1 (en) |
GB (1) | GB1363257A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4040286A (en) * | 1975-10-09 | 1977-08-09 | St. Joe Minerals Corporation | High-precision, fine-detail forging process |
US20030029216A1 (en) * | 2000-02-22 | 2003-02-13 | Leif Carlsson | Blank guided forming |
CN105728529A (en) * | 2014-12-12 | 2016-07-06 | 中国航空工业集团公司北京航空材料研究院 | Sinking slow-speed cold forming method of Z-section high-strength aluminum alloy profile |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0001198B1 (en) * | 1977-09-05 | 1980-08-20 | Scal Societe De Conditionnements En Aluminium | Process for the manufacture of articles by the thermoforming of aluminium or magnesium or of aluminium or magnesium base alloys |
GB2195281A (en) * | 1986-09-18 | 1988-04-07 | Edward Smethurst | Making moulds |
GB2298605B (en) * | 1995-03-04 | 1997-08-06 | British Aerospace | Forming an aluminium alloy component |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3420717A (en) * | 1966-03-28 | 1969-01-07 | Ibm | Metal softening process and product thereof |
US3567524A (en) * | 1968-12-13 | 1971-03-02 | Ibm | Method of producing moldings and the products of this method |
-
1971
- 1971-11-04 GB GB5132271A patent/GB1363257A/en not_active Expired
-
1972
- 1972-11-02 AU AU48454/72A patent/AU4845472A/en not_active Expired
- 1972-11-02 JP JP47110681A patent/JPS5146507B2/ja not_active Expired
- 1972-11-03 FR FR7239072A patent/FR2158536B1/fr not_active Expired
- 1972-11-06 US US00303718A patent/US3804677A/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3420717A (en) * | 1966-03-28 | 1969-01-07 | Ibm | Metal softening process and product thereof |
US3567524A (en) * | 1968-12-13 | 1971-03-02 | Ibm | Method of producing moldings and the products of this method |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4040286A (en) * | 1975-10-09 | 1977-08-09 | St. Joe Minerals Corporation | High-precision, fine-detail forging process |
US20030029216A1 (en) * | 2000-02-22 | 2003-02-13 | Leif Carlsson | Blank guided forming |
US6868708B2 (en) * | 2000-02-22 | 2005-03-22 | Avestapolarit Ab | Blank guided forming |
CN105728529A (en) * | 2014-12-12 | 2016-07-06 | 中国航空工业集团公司北京航空材料研究院 | Sinking slow-speed cold forming method of Z-section high-strength aluminum alloy profile |
Also Published As
Publication number | Publication date |
---|---|
AU4845472A (en) | 1974-05-23 |
GB1363257A (en) | 1974-08-14 |
FR2158536A1 (en) | 1973-06-15 |
FR2158536B1 (en) | 1974-08-19 |
JPS5146507B2 (en) | 1976-12-09 |
JPS4853963A (en) | 1973-07-28 |
DE2252930A1 (en) | 1973-05-10 |
DE2252930B2 (en) | 1975-08-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4334935A (en) | Production of aluminum alloy sheet | |
US3497402A (en) | Stabilized grain-size tantalum alloy | |
US3026197A (en) | Grain-refined aluminum-iron alloys | |
US2841512A (en) | Method of working and heat treating aluminum-magnesium alloys and product thereof | |
ES475808A1 (en) | Al-Mn Alloy and process of manufacturing semifinished products having improved strength properties | |
US3804677A (en) | Working of alloys | |
US3346427A (en) | Dispersion hardened metal sheet and process | |
US4652314A (en) | Process for producing products of Al-Li-Mg-Cu alloys having high levels of ductility and isotropy | |
US3310389A (en) | Sheets of aluminum alloy and methods of manufacturing same | |
US3498849A (en) | Methods of manufacturing clad aluminium alloys | |
US2506788A (en) | Method of enhancing physical properties of aluminum base alloys containing zinc and magnesium | |
US4874578A (en) | Aluminium alloy for superplastic forming | |
US2596485A (en) | Titanium base alloy | |
US4077813A (en) | Method of producing complex aluminum alloy parts of high temper, and products thereof | |
US3607456A (en) | Deep drawing steel and method of manufacture | |
US5223055A (en) | Method of making a sheet or strip of zircaloy with good formability and the strips obtained | |
US2804408A (en) | Process of treating tin bronze | |
US4521259A (en) | Nitrogen annealing of zirconium and zirconium alloys | |
GB815889A (en) | Rolling magnesium alloy | |
US3324699A (en) | Production of non-earing molybdenum sheet | |
JPH0517857A (en) | Method for treating metal matrix composite material | |
US3580747A (en) | Production of aluminum zinc magnesium alloy articles | |
US2826518A (en) | Aluminum base alloy article | |
US3496755A (en) | Method for producing flat-rolled product | |
US3843416A (en) | Superplastic zinc/aluminium alloys |