CN107385291A - A kind of high-performance Al Zn Mg Cu Zr Ce Ti alloys and its preparation technology - Google Patents

Abstract

This patent discloses a kind of high-performance Al Zn Mg Cu Zr Ce Ti alloys and its preparation technology, micro Ce and Ti are added on base alloy component base, and the feature process such as the annealing of preparation technology combination two-step homogenization and double_stage guide processing, make alloy aluminum of the present invention, zinc, magnesium, copper, zirconium, cerium（AlZnMgCuZrCeTi）Alloy ratio base alloy（AlZnMgCuZr）Fracture Toughness improve more than 20%.

Description

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy and its preparation process

technical field

The invention relates to an alloy production and preparation method, in particular to a high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy and a preparation process thereof.

Background technique

The 7000 series Al-Zn-Mg-Cu superhard series aluminum alloy is a heat-treatable and strengthened alloy, which has the advantages of low density, high strength, and good processing performance. It is widely used in the aerospace civil industry and is one of the main structural materials for aerospace. One, it is also widely used in transportation and other industries. With the development of the aerospace industry, people have gradually realized that fracture toughness has become a bottleneck that limits the further application of high-strength aluminum alloys. With the development of linear elasticity and fracture toughness mechanics and the application of damage safety design principles in practical work, people have a clearer understanding of the importance of the fracture toughness of structural materials, especially high-strength aluminum alloys. How to further improve the 7000 series Al-Zn- The fracture toughness of Mg-Cu alloys has become a common goal pursued by aluminum alloy researchers.

Contents of the invention

This patent invention is to design a high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy and its preparation process, adding trace amounts of Ce and Ti on the basis of the basic alloy components, and the preparation process combines double-stage homogenization annealing and Two-stage solid solution treatment and other characteristic processes have significantly improved the fracture toughness (K _1C ) of the invented alloy compared with the 7000 series Al-Zn-Mg-Cu-Zr base alloy, and the K _1C value has increased by more than 20%. The main contents of the invention are:

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy is characterized in that the alloy is composed of the following components by weight percentage: zinc 5.4-6.5%, magnesium 1.7-2.7%, copper 1.5- 2.5%, zirconium 0.07-0.15%, cerium 0.05-0.18%, titanium 0.08-0.16%, the total content of other impurities does not exceed 0.1%, and the content of individual impurity components does not exceed 0.05%, and the rest is Al.

Further, the impurity is one or more of iron, silicon, manganese, and ytterbium.

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy preparation process is characterized in that the alloy preparation process includes the following processes: batching, smelting and casting, homogenization treatment, hot rolling, cold rolling, two-stage solidification Melting treatment, quenching, aging treatment, the specific operation steps are as follows:

1) Ingredients: The raw materials used are: high-purity aluminum (99.95%), industrial pure magnesium (99.99%), aluminum-copper intermediate alloy (the content of aluminum-copper accounts for 50%, and the total content of impurities is less than 0.12%), aluminum-cerium intermediate Alloy (aluminum-cerium content accounts for 10%), aluminum-zirconium master alloy (aluminum-zirconium content accounts for 3%);

2) Melting and casting: Use graphite crucible or high-purity magnesia bricks coated with clay graphite paint as the lining material of the furnace to melt the alloy. During the melting process, the covering agent is always added. The order of feeding is: industrial high-purity aluminum--aluminum-copper intermediate alloy--aluminum Zirconium master alloy--aluminum cerium master alloy, cast after being completely melted, use hexachloroethane or argon for the first outgassing, then add industrial pure magnesium, and use hexachloroethane or argon for complete melting second breath

3) Homogenization treatment: Homogenize the ingot produced in step 2 in a salt bath furnace or an argon protection furnace. Keep warm for 15-16 hours at ℃;

4) Preheating for hot rolling and annealing before cold rolling: the specific operation can be carried out in an air resistance furnace, wherein the preheating temperature for hot rolling is 430°C ~ 440°C for 3-4 hours, and the annealing temperature before cold rolling is 420°C ~ 430°C for 2-3 hours;

5) Solution treatment: the specific operation is carried out in a salt bath furnace or an argon protection furnace. The two-stage solution treatment process is 280°C/2h+475°C/1h, and quenched in water at room temperature;

6) Aging treatment: The quenched alloy material is subjected to aging treatment within two hours. The aging treatment is carried out in a general constant temperature resistance furnace, and the process is: 120°C/20~26h.

Further, the covering agent in the step 2 is composed of sodium chloride, potassium chloride and sodium hexafluoroaluminate, and its mass ratio is sodium chloride: potassium chloride: sodium hexafluoroaluminate=4: 4:2.

Further, when batching in the step 1, the burning loss of magnesium should be supplemented, and the burning loss is 2.0-4.0% of the total mass.

Further, the melting temperature in the step 2 is about 760-780°C, and the casting temperature is about 690-720°C.

The beneficial effect of the invention is that it is different from various registered 7000 series Al-Zn-Mg-Cu-Zr alloys in the range of main components, and contains trace rare earth element Ce and transition group element Ti. Compared with the base alloy (AlZnMgCuZr), the fracture toughness value of the alloy aluminum, zinc, magnesium, copper, zirconium and cerium (AlZnMgCuZrCeTi) in the invention is increased by more than 20%.

detailed description

The present invention will be further described in detail in conjunction with specific embodiments now.

Example 1

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy, characterized in that the alloy is composed of the following components by weight percentage: zinc 5.92%, magnesium 2.35%, copper 2.15%, zirconium 0.13% , 0.07% cerium, 0.11% titanium, 0.045% iron, 0.042% silicon, and the rest is Al.

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy preparation process is characterized in that the alloy preparation process includes the following processes: batching, smelting and casting, homogenization treatment, hot rolling, cold rolling, two-stage solidification Melting treatment, quenching, aging treatment, the specific operation steps are as follows:

1) Ingredients: The raw materials used are: high-purity aluminum (99.95%), industrial pure magnesium (99.99%), aluminum-copper intermediate alloy (the content of aluminum-copper accounts for 50%, and the total content of impurities is less than 0.12%), aluminum-cerium intermediate Alloy (aluminum-cerium content accounts for 10%), aluminum-zirconium master alloy (aluminum-zirconium content accounts for 3%);

2) Melting and casting: graphite crucible is used as the furnace lining material to melt the alloy, and the covering agent is always added during the melting process. The order of feeding is: industrial high-purity aluminum--aluminum-copper master alloy--aluminum-zirconium master alloy--aluminum-cerium master alloy, Casting after complete melting, use hexachloroethane or argon for the first outgassing, then add industrial pure magnesium, and use hexachloroethane or argon for the second outgassing after complete melting;

3) Homogenization treatment: Homogenize the ingot produced in step 2 in a salt bath furnace or an argon protection furnace. The specific process is: first heat the ingot at 420°C for 14 hours, and then heat it to 465°C for heat preservation 15 hours; the first stage of the double-stage homogenization treatment is held at a lower temperature of 420°C for 14-16 hours to facilitate the formation of secondary precipitated dispersed phase (Al8Cu4Ce, TiAl3) particles of the microalloy components Ce and Ti; the second The grade is kept at a higher temperature of 465°C for 15-16 hours to make the alloy composition fully uniform.

4) Preheating for hot rolling and annealing before cold rolling: specific operations can be carried out in an air resistance furnace, wherein the preheating temperature for hot rolling is 430°C for 3 hours, and the annealing temperature before cold rolling is 420°C for 2 hours;

5) Solution treatment: The specific operation is carried out in a salt bath furnace or an argon protection furnace. The two-stage solution treatment process is 280°C/2h+475°C/1h, and quenched in water at room temperature; the first stage of two-stage solid solution Insulation at a lower temperature of 280°C for 2 hours is to allow the cold deformed alloy to recover and release the deformation storage energy, and the dispersed phase (Al8Cu4Ce, TiAl3) particles hinder recrystallization, so that the alloy will be solid solution treated at a higher temperature of 475°C The main purpose of the high-temperature solution treatment at 475°C for 1 hour is to obtain as high a degree of supersaturation as possible for the alloy matrix.

6) Aging treatment: within two hours, the quenched alloy material is subjected to aging treatment. The aging treatment is carried out in a general constant temperature resistance furnace, and the process is: 120℃/20h.

Preferably, the covering agent in step 2 is composed of sodium chloride, potassium chloride and sodium hexafluoroaluminate, and its mass ratio is sodium chloride: potassium chloride: sodium hexafluoroaluminate=4:4: 2.

Preferably, when step 1 is batched, the burning loss of magnesium should be supplemented, and the burning loss is 2.0% of the total mass.

Preferably, the melting temperature in step 2 is about 760°C, and the casting temperature is about 690°C.

Example 2

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy, characterized in that the alloy is composed of the following components by weight percentage: 6.23% zinc, 1.95% magnesium, 1.98% copper, and 0.09% zirconium , 0.12% cerium, 0.12% titanium, 0.046% iron, 0.041% silicon, and the rest is Al.

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy preparation process is characterized in that the alloy preparation process includes the following processes: batching, smelting and casting, homogenization treatment, hot rolling, cold rolling, two-stage solidification Melting treatment, quenching, aging treatment, the specific operation steps are as follows:

1) Ingredients: The raw materials used are: high-purity aluminum (99.95%), industrial pure magnesium (99.99%), aluminum-copper intermediate alloy (the content of aluminum-copper accounts for 50%, and the total content of impurities is less than 0.12%), aluminum-cerium intermediate Alloy (aluminum-cerium content accounts for 10%), aluminum-zirconium master alloy (aluminum-zirconium content accounts for 3%);

2) Melting and casting: graphite crucible is used as the furnace lining material to melt the alloy, and the covering agent is always added during the melting process. The order of feeding is: industrial high-purity aluminum--aluminum-copper master alloy--aluminum-zirconium master alloy--aluminum-cerium master alloy, Casting after complete melting, use hexachloroethane or argon for the first outgassing, then add industrial pure magnesium, and use hexachloroethane or argon for the second outgassing after complete melting;

3) Homogenization treatment: Homogenize the ingot produced in step 2 in a salt bath furnace or an argon protection furnace. The specific process is: first heat the ingot at 420°C for 15 hours, and then heat it to 465°C for heat preservation 15 hours;

4) Preheating for hot rolling and annealing before cold rolling: specific operations can be carried out in an air resistance furnace, wherein the preheating temperature for hot rolling is 435°C for 3 hours, and the annealing temperature before cold rolling is 425°C for 2 hours;

5) Solution treatment: the specific operation is carried out in a salt bath furnace or an argon protection furnace. The two-stage solution treatment process is 280°C/2h+475°C/1h, and quenched in water at room temperature;

6) Aging treatment: within two hours, the quenched alloy material is subjected to aging treatment. The aging treatment is carried out in a general constant temperature resistance furnace, and the process is: 120°C/22h.

Preferably, the covering agent in step 2 is composed of sodium chloride, potassium chloride and sodium hexafluoroaluminate, and its mass ratio is sodium chloride: potassium chloride: sodium hexafluoroaluminate=4:4: 2.

Preferably, when step 1 is batched, the burning loss of magnesium should be supplemented, and the burning loss is 3.0% of the total mass.

Preferably, the melting temperature in step 2 is about 770°C, and the casting temperature is about 700°C.

Example 3

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy, characterized in that the alloy is composed of the following components by weight percentage: 6.12% zinc, 2.23% magnesium, 2.35% copper, 0.11% zirconium , 0.12% cerium, 0.11% titanium, 0.043% iron, 0.049% silicon, and the rest is Al.

A high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy preparation process is characterized in that the alloy preparation process includes the following processes: batching, smelting and casting, homogenization treatment, hot rolling, cold rolling, two-stage solidification Melting treatment, quenching, aging treatment, the specific operation steps are as follows:

1) Ingredients: The raw materials used are: high-purity aluminum (99.95%), industrial pure magnesium (99.99%), aluminum-copper intermediate alloy (the content of aluminum-copper accounts for 50%, and the total content of impurities is less than 0.12%), aluminum-cerium intermediate Alloy (aluminum-cerium content accounts for 10%), aluminum-zirconium master alloy (aluminum-zirconium content accounts for 3%);

2) Melting and casting: graphite crucible is used as the furnace lining material to melt the alloy, and the covering agent is always added during the melting process. The order of feeding is: industrial high-purity aluminum--aluminum-copper master alloy--aluminum-zirconium master alloy--aluminum-cerium master alloy, Casting after complete melting, use hexachloroethane or argon for the first outgassing, then add industrial pure magnesium, and use hexachloroethane or argon for the second outgassing after complete melting;

3) Homogenization treatment: Homogenize the ingot produced in step 2 in a salt bath furnace or an argon protection furnace. The specific process is: first heat the ingot at 420°C for 16 hours, and then heat it to 465°C for heat preservation 16 hours;

4) Preheating for hot rolling and annealing before cold rolling: specific operations can be carried out in an air resistance furnace, wherein the preheating temperature for hot rolling is 440°C for 3 hours, and the annealing temperature before cold rolling is 430°C for 2 hours;

5) Solution treatment: the specific operation is carried out in a salt bath furnace or an argon protection furnace. The two-stage solution treatment process is 280°C/2h+475°C/1h, and quenched in water at room temperature;

6) Aging treatment: within two hours, the quenched alloy material is subjected to aging treatment, and the aging treatment is carried out in a general constant temperature resistance furnace, and the process is: 120°C/26h.

Further, the covering agent in the step 2 is composed of sodium chloride, potassium chloride and sodium hexafluoroaluminate, and its mass ratio is sodium chloride: potassium chloride: sodium hexafluoroaluminate=4: 4:2.

Further, when batching in the step 1, the burning loss of magnesium should be supplemented, and the burning loss is 4.0% of the total mass.

Further, the melting temperature in the step 2 is about 780°C, and the casting temperature is about 720°C.

Table 1. Weight percentage of alloy components in each embodiment (unit wt%):

According to the national standard GB/6497-14, thick plate sampling is to take 5 plates with a thickness of 2.5mm evenly from the surface to the center along the thickness direction of the plate, and process the tensile test in the rolling direction (L-T) and the long transverse direction (T-L). Then take a 2.5 mm thick plate perpendicular to the thickness direction of the plate, process a short transverse (S-L) tensile sample, and perform a tensile performance test on an electronic universal testing machine.

Table 2. Example and base alloy fracture toughness (K _1C ) test table:

As can be seen from Table 2, along with the difference of alloy batching composition weight in embodiment 1,2,3, the fracture toughness that it shows is different to some extent, and the processing rolling direction (LT) fracture toughness in above-mentioned 3 embodiments is all greater than equal to 42MPa·m ^1/2 , the fracture toughness of the long transverse direction (TL) is greater than or equal to 35MPa·m ^1/2 , and the fracture toughness of the short transverse direction (SL) is greater than 27MPa·m ^1/2 , the fracture toughness exhibited in all aspects Both are better than the fracture toughness values of the base alloy.

Inspired by the above-mentioned ideal embodiment according to the present invention, through the above-mentioned description content, relevant workers can make various changes and modifications within the scope of not departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, but must be determined according to the scope of the claims.

Claims (6)

1. A kind of 1. high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloys, it is characterised in that alloy described by weight percentage by with The following group packet into：Zinc 5.4-6.5%, magnesium 1.7-2.7%, copper 1.5-2.5%, zirconium 0.07-0.15%, cerium 0.05-0.18%, titanium 0.08- 0.16%, other content of impurities are no more than 0.1 %, and single impurity component content is no more than 0.05%, and remaining is Al.
2. 2. a kind of high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloys according to claim 1, it is characterised in that described miscellaneous Matter is the one or more in iron, silicon, manganese, ytterbium.
3. 3. a kind of high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy preparation technologies, it is characterised in that alloy preparation technology includes Below scheme：Dispensing, melting casting, Homogenization Treatments, hot rolling, cold rolling, double_stage guide processing, quenching, Ageing Treatment, specific behaviour It is as follows to make step:

   1）Dispensing:Raw materials are：Rafifinal（99.95%）, pure magnesium (99.99%), aluminum bronze intermediate alloy (aluminium-copper 0.12%) content accounting 50%, content of impurities are less than, aluminium cerium intermediate alloy（Aluminium-cerium content accounting 10%）, aluminium zirconium hardener （Aluminium-zirconium content accounting 3%）；

   2）Melting is cast:Clay graphite paint is applied with graphite crucible or high-purity magnesium oxide brick and does hearth inner lining material molten alloy, Fusion process adds coverture always, and charging sequence is：Industrial rafifinal -- aluminum bronze intermediate alloy -- aluminium zirconium hardener -- aluminium cerium Intermediate alloy, cast until completely melted, after carrying out first time outlet with carbon trichloride or argon gas, add technical pure Magnesium, second of outlet is carried out with carbon trichloride or argon gas after being completely melt；

   3）Homogenization Treatments：The ingot casting that step 2 produces is subjected to Homogenization Treatments, specific work in salt bath furnace or argon gas protection stove Skill is：It will first be doomed to be incubated 14-16 hours at 420 DEG C, then be heated to 465 DEG C of insulation 15-16 hours；

   4）Annealed before hot rolling preheating, cold rolling：Concrete operations can be carried out in air resistance furnace, wherein, hot rolling preheating temperature is 430 DEG C ~ 440 DEG C of insulation 3-4 hours, annealing temperature is 420 DEG C ~ 430 DEG C insulation 2-3 hours before cold rolling；

   5）Solution treatment：Concrete operations are carried out in salt bath furnace or argon gas protection stove, and double_stage guide handling process is 280 DEG C/2h+ 475 DEG C/1h, and in room temperature quenching-in water；

   6）Ageing Treatment：The alloy material after quenching is subjected to Ageing Treatment in two hours, Ageing Treatment is in general constant temperature electricity Carried out in resistance stove, technique is：120℃ /20~26h.
4. 4. a kind of high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy manufacturing methods according to claim 3, its feature exist In the coverture in the step 2 closes sodium aluminate by sodium chloride, potassium chloride and hexafluoro and formed, and it is sodium chloride in mass ratio：Chlorine Change potassium：Hexafluoro closes sodium aluminate=4；4；2.
5. 5. a kind of high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy manufacturing methods according to claim 3, its feature exist When, step 1 dispensing, the scaling loss amount of magnesium is supplemented, scaling loss amount is the 2.0-4.0% of gross mass.
6. 6. a kind of high-performance Al-Zn-Mg-Cu-Zr-Ce-Ti alloy manufacturing methods according to claim 3, its feature exist In the smelting temperature of the step 2 is about 760 ~ 780 DEG C, and cast temperature is about 690 ~ 720 DEG C.