CN113088839A - Densification treatment method and application of spray-deposited ultrahigh-strength aluminum alloy and densified preform of ultrahigh-strength aluminum alloy - Google Patents
Densification treatment method and application of spray-deposited ultrahigh-strength aluminum alloy and densified preform of ultrahigh-strength aluminum alloy Download PDFInfo
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Abstract
The invention discloses a densification treatment method for spray-deposited ultrahigh-strength aluminum alloy, which is characterized in that a spray-deposited ultrahigh-strength aluminum alloy cylindrical preform with a gap is densified in a deformation process through surrounding treatment and high-frequency forging deformation, a blank is limited by a surrounding material in the deformation process, the blank is different from edge cracking caused by a tension-compression stress state of free upsetting deformation, the main stress state of the blank is three-dimensional compressive stress, the main deformation state is two-dimensional compression and one-dimensional extension, a deformation mechanical state diagram is favorable for improving the plasticity of metal, the deformation amount is small each time, the friction resistance is reduced when the metal deforms, the deformation work is reduced, the surface quality of the deformed material is good, the cracking phenomenon does not occur, and the gap in the material is welded under high temperature and high pressure in the deformation process, so that the alloy is densified and is favorable for subsequent processing.
Description
Technical Field
The invention relates to the technical field of plastic processing of metal materials, in particular to a spray deposition ultrahigh-strength aluminum alloy densification treatment method, application and a densification preform thereof.
Background
The jet deposition technology overcomes the defects of thick and large structure, segregation, complex powder metallurgy process procedure, serious sintering oxidation and the like of the traditional metallurgy casting technology. At present, the spray deposition technology is widely applied to research and production of ultra-high strength aluminum alloy, but the ultra-high strength aluminum alloy material prepared by the spray deposition technology is not compact in structure, contains a certain amount of gaps, generally has the compactness of about 96%, and is very brittle. For spray-deposited 7-series Al-Zn-Mg-Cu ultrahigh-strength aluminum alloys (such as 7034, 7136, 7093 and the like) with a total alloy content exceeding 12%, the plasticity is very low, and the direct die forging treatment causes forging cracking and necessitates densification.
The common densification method is extrusion or rolling deformation, but the extrusion and rolling deformation densification has strong directionality, and the material can form strong texture during subsequent die forging, so that the performance of the forging in the direction perpendicular to the texture is low. Aiming at the production of spray-deposited ultrahigh-strength aluminum alloy die forgings with small specification and size, the material has low performance of the final die forgings in the direction perpendicular to the texture due to small size and obvious extrusion or rolling densification texture, so extrusion or rolling densification treatment cannot be adopted, and cracking phenomenon can occur in the forging process without densification treatment, so that the forming cannot be realized.
Disclosure of Invention
The invention aims to provide a densification treatment method for spray-deposited ultrahigh-strength aluminum alloy, aiming at the defect that the performance of a forge piece in the vertical texture direction is lower due to the densification of extrusion and rolling deformation in the prior art. The method enables a cylindrical preform of spray-deposited ultrahigh-strength aluminum alloy with a gap to be densified in the deformation process through surrounding treatment and high-frequency forging deformation.
The invention also aims to provide application of the densification treatment method in densification treatment of spray-deposited ultrahigh-strength aluminum alloy.
It is another object of the present invention to provide an aluminum alloy preform obtained by the densification treatment method.
The technical scheme adopted for realizing the purpose of the invention is as follows:
a densification treatment method for spray-deposited ultrahigh-strength aluminum alloy comprises the following steps:
step 1: machining a spray-deposited ultra-high strength aluminum alloy blank into a cylindrical preform;
step 2: processing a cylindrical surrounding ring by using aluminum alloy as a surrounding material, wherein the diameter and the height of the inner circle of the cylindrical surrounding ring are respectively the same as the diameter and the height of the bottom surface of the cylindrical preform;
and step 3: pressing the cylindrical preform into the cylindrical containment ring with a clearance fit to produce a containment densified assembly;
and 4, step 4: heating the surrounding densified assembly;
and 5: forging and deforming the heated surrounding densification assembly to ensure that the cylindrical preform deforms and densifies under the combined action of the cylindrical surrounding ring and the forging pressure to obtain a round cake;
step 6: the cylindrical surrounding ring on the resulting disk is removed to yield a densified preform.
In the above technical scheme, the aluminum alloy in the step 2 is 7D68 aluminum alloy, 7a60 aluminum alloy or 7075 aluminum alloy.
In the solution described above, the vertical deformation of the tortilla in step 5 is more than 50%, preferably 58-75%, compared to the cylindrical preform in step 1.
In the technical scheme, in the step 1, the diameter of the bottom surface of the cylindrical preform is 50-100mm, and the height of the cylindrical preform is 60-120 mm; in step 5, the height of the round cake after forging deformation is 15-50 mm.
In the above technical scheme, in the step 2, the wall thickness of the cylindrical surrounding ring is 8-20 mm.
In the solution described above, in step 3, the clearance fit of the inner circle of the cylindrical containment ring with the outer circle of the cylindrical preform is within the tolerance H6/H5 or H6/g 5.
In the technical scheme, in the step 4, a heating furnace is adopted for heating, the heating temperature is 360-420 ℃, and the heat preservation time is 1-2 h.
In the technical scheme, in the step 5, a high-frequency rotary forging machine is adopted for forging deformation, and the forging frequency is 6000-10000 times/min.
The invention also aims to provide application of the densification treatment method in densification treatment of the spray-deposited ultrahigh-strength aluminum alloy, wherein the spray-deposited ultrahigh-strength aluminum alloy is a spray-deposited 7-series Al-Zn-Mg-Cu ultrahigh-strength aluminum alloy, and the total alloy content is more than 12%.
Another object of the invention is a densified preform obtained using the densification treatment method described above, said densified preform having a density of more than 99%, preferably between 99.3% and 99.7%.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the densification treatment method for the spray-deposited ultrahigh-strength aluminum alloy, provided by the invention, the spray-deposited ultrahigh-strength aluminum alloy cylindrical preform with the gap is densified in the deformation process through surrounding treatment and high-frequency forging deformation, and the aluminum alloy preform obtained by applying the spray-deposited ultrahigh-strength aluminum alloy densification treatment method has the compactness of more than 99% and even up to 99.7%, and can be effectively prevented from cracking or being incapable of being formed in the forging process.
2. The spray deposition ultrahigh-strength aluminum alloy densification treatment method provided by the invention has the advantages that the blank is limited by the surrounding material in the deformation process, the edge cracking is different from the edge cracking caused by the tensile and compressive stress state of free upsetting deformation, the main stress state is three-way compressive stress, the main deformation state is two-way compression and one-way extension, the deformation mechanical state diagram is favorable for improving the plasticity of metal, the deformation amount is small each time, the friction resistance is reduced when the metal deforms, the deformation work is reduced, the surface quality of the deformed material is good, the cracking phenomenon does not occur, and meanwhile, the gaps in the material are welded under high temperature and high pressure in the deformation process, so that the alloy is densified, and the subsequent processing is favorable.
3. The aluminum alloy preform provided by the invention can be used for producing small-size spray-deposited ultrahigh-strength aluminum alloy die forgings without influencing the performance of the final die forgings in the direction vertical to the texture.
Drawings
Figure 1 shows a schematic cross-sectional view of the assembly of a cylindrical preform and a cylindrical surrounding ring in step 3.
In the figure: 1-cylindrical preform, 2-cylindrical surrounding ring.
Detailed Description
The present invention will be described in further detail with reference to specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
The total alloy content of the spray-deposited 7034 ultrahigh-strength aluminum alloy exceeds 12%, the compactness of the spray-deposited blank is 96.5%, and the material in the state is very brittle and tends to crack due to direct upsetting or die forging.
A densification treatment method for spray-deposited ultrahigh-strength aluminum alloy comprises the following steps:
step 1, preparing a preform
The spray-deposited 7034 ultra-high strength aluminum alloy blank is processed into a cylindrical preform, wherein the diameter D of the bottom surface of the cylindrical preform is 50mm, and the height h is 120 mm.
The method is characterized in that a cylindrical surrounding ring is processed by adopting a 7A60 aluminum alloy with good plasticity as a surrounding material, the diameter d of the inner circle of the cylindrical surrounding ring is 50mm, the height H is 120mm, the wall thickness is 8mm, the inner circle of the cylindrical surrounding ring is in clearance fit with the outer circle of a cylindrical preform, and the fit tolerance is H6/H5.
Step 3, assembling
The cylindrical preform is pressed into a cylindrical surrounding ring to form a surrounding densified assembly (as shown in figure 1).
Step 4, heating
And (3) heating the surrounding densification assembly in a heating furnace at 360 ℃ for 1 h.
Step 5, deformation densification
And performing forging deformation on the heated surrounding densification assembly on a high-frequency rotary forging machine, so that the cylindrical preform is subjected to deformation densification under the combined action of the cylindrical surrounding ring and forging pressure. The forging frequency is 6000 times/min, the height of the round cake after forging deformation is 50mm, and the vertical deformation is 58.3 percent and exceeds 50 percent.
Step 6, removing the surrounding material
And removing the cylindrical surrounding ring of the deformed and densified round cake by adopting a machining method to obtain a densified deformed 7034 aluminum alloy preform.
The processing method comprises the steps of surrounding treatment and high-frequency forging deformation, so that a jet-deposited ultrahigh-strength aluminum alloy cylindrical preform with a gap is densified in the deformation process, the blank is limited by a surrounding material in the deformation process, the edge of the blank is cracked due to a tensile stress state different from free upsetting deformation, the main stress state is three-dimensional compressive stress, the main deformation state is two-dimensional compression and one-dimensional extension, the deformation mechanical state diagram is favorable for improving the plasticity of metal, the deformation amount is small each time, the friction resistance is reduced when the metal deforms, the deformation work is reduced, the surface quality of the deformed material is good, the cracking phenomenon does not occur, and the gap in the material is welded under high temperature and high pressure in the deformation process, so that the alloy is densified and favorable for subsequent processing.
The spray-deposited ultrahigh-strength aluminum alloy blank obtained by the spray-deposited ultrahigh-strength aluminum alloy densification treatment method has good surface quality, the density is improved from 96.5% to 99.5%, and the cracking phenomenon does not occur in subsequent die forging and processing.
Example 2
The total alloy content of the jet-deposited 7136 ultrahigh-strength aluminum alloy exceeds 12%, the compactness of the jet-deposited blank is 96.8%, and the material in the state is very brittle and tends to crack due to direct upsetting or die forging.
A densification treatment method for spray-deposited ultrahigh-strength aluminum alloy comprises the following steps:
step 1, preparing a preform
Processing the jet-deposited 7136 ultrahigh-strength aluminum alloy blank into a cylindrical preform, wherein the diameter D of the bottom surface of the cylindrical preform is 100mm, and the height h is 60 mm.
The cylinder surrounding ring is processed by adopting 7075 aluminum alloy with better plasticity as a surrounding material, the diameter d of the inner circle of the cylinder surrounding ring is 100mm, the height H is 60mm, the wall thickness is 20mm, the inner circle of the cylinder surrounding ring is in clearance fit with the outer circle of the cylindrical preform, and the fit tolerance is H6/g 5.
Step 3, assembling
The cylindrical preform is pressed into a cylindrical surrounding ring to form a surrounding densified assembly (as shown in figure 1).
Step 4, heating
And (3) heating the surrounding densified assembly in a heating furnace at the temperature of 420 ℃ for 2 h.
Step 5, deformation densification
And performing forging deformation on the heated surrounding densification assembly on a high-frequency rotary forging machine, so that the cylindrical preform is subjected to deformation densification under the combined action of the cylindrical surrounding ring and forging pressure. The forging frequency is 10000 times/min, the height of the round cake after forging deformation is 15mm, the vertical deformation is 75.0 percent, and the vertical deformation exceeds 50 percent.
Step 6, removing the surrounding material
And removing the cylindrical surrounding ring of the deformed and densified round cake by adopting a machining method to obtain a densified deformed 7136 aluminum alloy preform.
The spray-deposited ultrahigh-strength aluminum alloy blank obtained by the spray-deposited ultrahigh-strength aluminum alloy densification treatment method has good surface quality, the density is improved to 99.7% from 97% to 96.8%, and no cracking phenomenon occurs in subsequent die forging and processing.
Example 3
The total alloy content of the spray-deposited 7093 ultrahigh-strength aluminum alloy exceeds 12%, the compactness of the spray-deposited blank is 95.6%, and the material in the state is very brittle and tends to crack due to direct upsetting or die forging.
A densification treatment method for spray-deposited ultrahigh-strength aluminum alloy comprises the following steps:
step 1, preparing a preform
The spray-deposited 7093 ultra-high strength aluminum alloy blank is processed into a cylindrical preform, wherein the diameter D of the bottom surface of the cylindrical preform is 80mm, and the height h is 100 mm.
The method is characterized in that a cylindrical surrounding ring is processed by adopting a 7D68 aluminum alloy with good plasticity as a surrounding material, the diameter D of the inner circle of the cylindrical surrounding ring is 80mm, the height H is 100mm, the wall thickness is 15mm, the inner circle of the cylindrical surrounding ring is in clearance fit with the outer circle of a cylindrical preform, and the fit tolerance is H6/H5.
Step 3, assembling
The cylindrical preform is pressed into a cylindrical surrounding ring to form a surrounding densified assembly (as shown in figure 1).
Step 4, heating
And (3) heating the surrounding densification assembly in a heating furnace at 360 ℃ for 1 h.
Step 5, deformation densification
And performing forging deformation on the heated surrounding densification assembly on a high-frequency rotary forging machine, so that the cylindrical preform is subjected to deformation densification under the combined action of the cylindrical surrounding ring and forging pressure. The forging frequency is 8000 times/min, the height of the round cake after forging deformation is 35mm, and the vertical deformation is 65 percent and exceeds 50 percent.
Step 6, removing the surrounding material
And removing the cylindrical surrounding ring of the deformed and densified round cake by adopting a machining method to obtain a densified deformed 7093 aluminum alloy preform.
The spray-deposited ultrahigh-strength aluminum alloy blank obtained by the spray-deposited ultrahigh-strength aluminum alloy densification treatment method has good surface quality, the density is improved from 95.6% to 99.3%, and the cracking phenomenon does not occur in subsequent die forging and processing.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A densification treatment method for spray-deposited ultrahigh-strength aluminum alloy is characterized by comprising the following steps:
step 1: machining a spray-deposited ultra-high strength aluminum alloy blank into a cylindrical preform;
step 2: processing a cylindrical surrounding ring by using aluminum alloy as a surrounding material, wherein the diameter and the height of the inner circle of the cylindrical surrounding ring are respectively the same as the diameter and the height of the cylindrical preform;
and step 3: pressing the cylindrical preform into the cylindrical containment ring with a clearance fit to produce a containment densified assembly;
and 4, step 4: heating the surrounding densified assembly;
and 5: forging and deforming the heated surrounding densification assembly to ensure that the cylindrical preform deforms and densifies under the combined action of the cylindrical surrounding ring and the forging pressure to obtain a round cake;
step 6: the cylindrical surrounding ring on the resulting disk is removed to yield a densified preform.
2. The densification process of claim 1, wherein the aluminium alloy in step 2 is a 7D68 aluminium alloy, a 7a60 aluminium alloy or a 7075 aluminium alloy.
3. Densification process in accordance with claim 1 characterized in that the wafer in step 5 is deformed more than 50%, preferably 58-75% vertically compared to the cylindrical preform in step 1.
4. Densification treatment process according to claim 3, characterized in that in step 1 the cylindrical preform has a base diameter of 50-100mm and a height of 60-120 mm; in step 5, the height of the round cake after forging deformation is 15-50 mm.
5. Densification treatment method according to claim 1, characterised in that in step 2 the wall thickness of the cylindrical surrounding ring is 8-20 mm.
6. The densification process of claim 5, wherein in step 3, the inner circle of the cylindrical surrounding ring is clearance fit to the outer circle of the cylindrical preform by a tolerance of H6/H5 or H6/g 5.
7. The densification treatment method according to claim 1, wherein in step 4, a heating furnace is used for heating, the heating temperature is 360-420 ℃, and the holding time is 1-2 h.
8. The densification processing method according to claim 1, wherein in step 5, a high frequency rotary forging machine is used to perform forging deformation, wherein the forging frequency is 6000-.
9. Use of the densification treatment method according to any of claims 1-8 in a densification treatment of a spray deposited ultra high strength aluminium alloy, wherein the spray deposited ultra high strength aluminium alloy is a spray deposited 7 series Al-Zn-Mg-Cu ultra high strength aluminium alloy with a total alloy content of more than 12%.
10. Densified preform obtained by the densification treatment method according to any of claims 1-8, wherein the densified preform has a density of more than 99%, preferably 99.3-99.7%.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115488274A (en) * | 2022-09-28 | 2022-12-20 | 歌尔股份有限公司 | Magnesium-lithium alloy material, preparation method and forging device |
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Application publication date: 20210709 |