WO2017086470A1 - アルミニウム合金材及びその製造方法 - Google Patents
アルミニウム合金材及びその製造方法 Download PDFInfo
- Publication number
- WO2017086470A1 WO2017086470A1 PCT/JP2016/084338 JP2016084338W WO2017086470A1 WO 2017086470 A1 WO2017086470 A1 WO 2017086470A1 JP 2016084338 W JP2016084338 W JP 2016084338W WO 2017086470 A1 WO2017086470 A1 WO 2017086470A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- less
- aluminum alloy
- sample
- alloy material
- treatment
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
- C22C21/10—Alloys based on aluminium with zinc as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
-
- 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
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
- C22F1/053—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with zinc as the next major constituent
-
- 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
-
- 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
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
Definitions
- the present disclosure relates to an aluminum alloy material and a manufacturing method thereof.
- a 7000 series aluminum alloy obtained by adding Zn and Mg to Al is known.
- the 7000 series aluminum alloy shows high strength because fine precipitates of Al—Mg—Zn series are aged.
- those added with Cu in addition to Zn and Mg exhibit the highest strength among the aluminum alloys.
- the 7000 series aluminum alloy is manufactured by, for example, hot extrusion, and is used for applications such as sports equipment in addition to aircraft, vehicles, and other transport equipment and machine parts that require high strength.
- characteristics required for use in the above applications include impact absorption (toughness) and stress corrosion cracking resistance (hereinafter referred to as SCC resistance) in addition to strength.
- SCC Stress Corrosion Cracking.
- an aluminum alloy extruded material described in Patent Document 1 has been proposed.
- the metal structure As a technique for solving the above-described surface quality problems, for example, the generation of streaks, it is possible to make the metal structure an equal granular recrystallized structure instead of fibrous. By setting it as a recrystallized structure, it can suppress that the compound which precipitated on the grain boundary is arrange
- a 7000 series aluminum alloy is made to have a recrystallized structure, the strength is reduced as compared with a fibrous structure, and toughness and SCC resistance may be reduced. Furthermore, by using a recrystallized structure, the occurrence of streak patterns can be reduced, but scale-like patterns become conspicuous. As described above, conventionally, it has been difficult to use a 7000 series aluminum alloy in applications that require characteristics such as SCC resistance and surface quality in addition to high strength and high toughness.
- the aluminum alloy material according to one aspect of the present disclosure includes Zn: 6.5% (mass%, the same applies below) to 8.5% or less, Mg: 0.5% to 1.5%, Cu: 0.10 %: Fe: 0.30% or less, Si: 0.30% or less, Mn: less than 0.05%, Cr: less than 0.05%, Zr: 0.05% or more and 0.10% or less, Ti: Containing 0.001% or more and 0.05% or less, the remainder having a chemical component composed of Al and inevitable impurities, the mass ratio of Zn to Mg (Zn / Mg) being 5 to 16 and metal
- the structure consists of a recrystallized structure with an equal grain.
- the above-mentioned aluminum alloy material has the above-mentioned specific chemical component, and the metal structure is composed of an equi-grain recrystallized structure. Therefore, compared with the case where a metal structure is a fibrous structure, the deterioration of the surface quality after surface treatments, such as an anodizing process, can be suppressed.
- the upper limit of the Mg content the precipitation of compounds on the grain boundaries is suppressed while ensuring high strength.
- the generation of scaly patterns on the surface can be suppressed.
- it can suppress that the surface color tone is tinged with yellow by surface treatment by restrict
- the method for producing an aluminum alloy material according to another aspect of the present disclosure is a method for producing an aluminum alloy material having a recrystallized structure in which the metal structure is an equal grain, and Zn: 6.5% (mass%, the same applies hereinafter) Exceeding 8.5% or less, Mg: 0.5% to 1.5%, Cu: 0.10% or less, Fe: 0.30% or less, Si: 0.30% or less, Mn: 0.05% Less than, Cr: less than 0.05%, Zr: 0.05% or more and 0.10% or less, Ti: 0.001% or more and 0.05% or less, with the balance being Al and inevitable impurities And a mass ratio of Zn to Mg (Zn / Mg) of 5 to 16 is produced, and the ingot is heated at a temperature of 540 ° C. to 580 ° C. for 1 hour to 24 hours. Perform homogenization.
- an ingot having the specific chemical component and having a mass ratio of Zn to Mg (Zn / Mg) in the specific range is manufactured. Then, the ingot is homogenized under the specific conditions.
- the heating temperature in the homogenization treatment is set to a high temperature exceeding 540 ° C. and not higher than 580 ° C.
- the above-described aluminum alloy material that is, the metal structure is composed of an equi-grain recrystallized structure. And a high-strength aluminum alloy material can be easily obtained.
- Test piece 20 ... Sample
- Zn coexists with Mg and has the effect of precipitating the ⁇ ′ phase and improving the strength.
- the range of Zn content is more than 6.5% and not more than 8.5%.
- Zn content is 6.5% or less, the amount of precipitation of the ⁇ ′ phase is reduced, so that the effect of improving the strength is reduced.
- Zn content exceeds 8.5%, since hot workability falls, productivity falls.
- a preferable range of the Zn content is 7.0% or more and 8.0% or less.
- Mg has the effect of coexisting with Zn and precipitating the ⁇ ′ phase to improve the strength.
- the range of Mg content is 0.5% or more and 1.5% or less.
- the upper limit of the Mg content it is possible to suppress the precipitation of the compound on the grain boundaries (crystal grain boundaries, subgrain boundaries, etc.) while obtaining the effect of improving the strength. Therefore, in the surface treatment such as anodizing treatment, the amount of the compound deposited on the grain boundary is etched during the pretreatment, and the occurrence of the scale-like pattern on the surface after the surface treatment can be suppressed.
- the Mg content is less than 0.5%, the amount of precipitation of the ⁇ ′ phase is reduced, so that the effect of improving the strength is reduced.
- the Mg content exceeds 1.5%, a coarse compound is likely to be formed on the grain boundary, and the amount of the compound etched during the pretreatment of the surface treatment such as anodizing treatment increases. Therefore, a scale pattern is generated on the surface after the surface treatment, and the surface quality is deteriorated.
- the Mg content is preferably 1.0% or more and 1.3% or less.
- Cu may be mixed when a recycled material is used as a raw material for the aluminum alloy material.
- the inclusion of Cu contributes to the improvement of strength, but the surface treatment such as anodizing treatment may cause a change in color tone such that the color tone of the surface becomes yellowish, and the surface quality may be deteriorated. Therefore, especially when the color tone of the surface after the surface treatment is regarded as important, it is necessary to regulate the upper limit of the Cu content. Therefore, by restricting the upper limit of the Cu content to 0.10% or less, the above-described deterioration of the surface quality can be suppressed.
- the Cu content is preferably 0.08% or less.
- Fe, Si, Mn, Cr Fe and Si may be mixed as impurities in the aluminum metal. Mn and Cr may be mixed when a recycled material is used as a raw material for the aluminum alloy material.
- Fe, Si, and Mn are recrystallized by forming an Al—Mn, Al—Mn—Fe, and Al—Mn—Fe—Si intermetallic compound with Al. Has the effect of suppressing oxidization.
- Cr has an action of suppressing recrystallization by forming an Al—Cr intermetallic compound with Al. Therefore, the inclusion of the four components suppresses the formation of a recrystallized structure, and a fibrous structure is formed instead.
- Zr is added to obtain a fine and uniform recrystallized structure.
- the range of Zr content is 0.05% or more and 0.10% or less.
- Zr forms a fine Al—Zr compound with Al.
- the crystal structure of the Al—Zr-based compound changes depending on the temperature of the ingot homogenization process during the manufacturing process of the aluminum alloy material.
- the temperature of the homogenization treatment is 540 ° C. or less, metastable phase having a matrix phase and inconsistent L1 2 -type structure is generated, thereby suppressing the recrystallization in tissue after hot working tends to be fibrous tissue .
- by performing the homogenization treatment at 540 ° C. greater than 580 ° C.
- Al-Zr based compounds changes in the equilibrium phase having a D0 23 type structure, after hot working an equal granular rather than fibrous tissue While becoming a recrystallized structure, the movement of a crystal grain boundary is prevented and the coarsening of a recrystallized grain is suppressed.
- the Zr content is less than 0.05%, it is difficult to obtain the effect of suppressing the coarsening of the recrystallized grains, resulting in an uneven metal structure in which the recrystallized grains are partially coarsened. Problems such as spotted patterns appearing on the surface after the surface treatment occur, and the surface quality deteriorates.
- the Zr content exceeds 0.10%, the Al—Zr compound is more densely distributed, so that a fibrous structure is formed by suppressing recrystallization. A streak pattern is generated on the surface of the surface, and the surface quality deteriorates.
- Ti is added to make the ingot crystal grains finer.
- the range of Ti content is 0.001% or more and 0.05% or less.
- the Ti content is less than 0.001%, the effect of refining crystal grains is reduced, and therefore, a patchy pattern is likely to occur on the surface after the surface treatment such as anodizing treatment, and the surface quality is deteriorated.
- the Ti content exceeds 0.05%, point defects are generated on the surface after the surface treatment due to an Al—Ti intermetallic compound formed with Al. It becomes easier and the surface quality decreases.
- Al and inevitable impurities may be used.
- an element other than the above elements added to an aluminum alloy is allowed as an inevitable impurity within a range that does not significantly affect the characteristics.
- the aluminum alloy material has a mass ratio of Zn to Mg (Zn / Mg) of 5 to 16.
- Zn / Mg mass ratio of Zn to Mg
- higher strength can be obtained by adding Zn or Mg.
- Zn is added in a large amount
- hot workability is reduced
- Mg is added in a large amount
- formation of a coarse compound is promoted to reduce surface treatment properties and toughness.
- the SCC resistance is lowered by changing the metal structure to a recrystallized structure.
- the following characteristics can be obtained by regulating the upper limit of the contents of Zn and Mg and further setting the mass ratio (Zn / Mg) in the specific range.
- the absolute value of the production amount of the MgZn 2 compound is reduced by regulating the upper limit of the contents of Zn and Mg.
- the mass ratio (Zn / Mg) is set to 16 or less, that is, in addition to relatively reducing the Mg content, the mass ratio (Zn / Mg) is regulated to 16 or less, whereby the MgZn 2 compound is coarse. It is possible to improve toughness by suppressing the growth to a fine compound.
- the SCC resistance in general, in the 7000 series aluminum alloy, the potential of the parent phase near the grain boundary becomes noble with respect to the MgZn 2 compound precipitated at the grain boundary. As a result, anodic dissolution occurs and a crack is formed in the vicinity of the grain boundary. As a result, stress is concentrated, and cracks are generated and propagated.
- the mass ratio (Zn / Mg) is set to 5 or more, that is, in addition to relatively increasing the amount of Zn dissolved in the matrix, the mass ratio (Zn / Mg) is regulated to 5 or more.
- the upper limit of the contents of Zn and Mg is regulated, and the mass ratio (Zn / Mg) is set to 5 or more and 16 or less, so that the surface quality is good and the toughness and A high-strength aluminum alloy material excellent in SCC resistance can be obtained.
- the mass ratio (Zn / Mg) is less than 5 within the above-described Zn and Mg content range, the effect of reducing and miniaturizing the compound of Zn and Mg is small, and the effect of improving toughness is sufficient. Can not be obtained.
- the mass ratio (Zn / Mg) exceeds 16, since the Zn content increases, anodic dissolution near the grain boundary tends to occur, and the SCC resistance decreases.
- a preferable range of the mass ratio (Zn / Mg) is 7 or more and 16 or less.
- the above-mentioned aluminum alloy material is composed of a recrystallized structure having a uniform metal structure.
- the recrystallized structure is a metal structure composed of uniform recrystallized grains.
- the metal structure can be confirmed, for example, by observing the surface or cross section of the aluminum alloy material with a polarizing microscope.
- the recrystallized structure has an average grain size of 500 ⁇ m or less in a cross section parallel to a direction orthogonal to a processing direction of the aluminum alloy material (for example, an extrusion direction in the case of an extruded material), and
- the difference between the maximum value and the minimum value of the grain size of the crystal grains is preferably less than 300 ⁇ m.
- the crystal grain size of the recrystallized structure becomes more uniform, and good surface quality can be obtained.
- processing in the processing direction includes extrusion processing, rolling processing, and the like.
- the “cross section parallel to the direction orthogonal to the processing direction” refers to, for example, a cross section parallel to the width direction (cross section orthogonal to the thickness direction) when the processing direction is the length direction.
- the crystal grain in the recrystallized structure exceeds 500 ⁇ m, the crystal grain becomes excessively coarse, and there is a risk that a spotted pattern resulting from the coarse crystal grain is generated on the surface after the surface treatment such as anodizing treatment. is there.
- the difference between the maximum value and the minimum value of the crystal grain size is 300 ⁇ m or more, the metal structure becomes non-uniform, and the light reflection state may be non-uniform on the surface after the surface treatment.
- the above-mentioned aluminum alloy material preferably has a yield strength specified in JIS Z2241 (ISO 6892-1) of 300 MPa or more, more preferably 350 MPa or more. As a result, it is possible to relatively easily obtain strength characteristics that can cope with thinning for weight reduction.
- an ingot having the above chemical component and having a mass ratio of Zn to Mg (Zn / Mg) of 5 to 16 is produced.
- a homogenization treatment is performed by heating at a temperature of over 580 ° C. and below 580 ° C. for 1 hour to 24 hours.
- Al-Zr-based compounds present in the ingot becomes metastable phase having inconsistent L1 2 -type structure and matrix organization after hot working In this, recrystallization is suppressed and a fibrous structure tends to be formed. This causes a streak pattern on the surface after the surface treatment such as anodizing, and the surface quality is deteriorated.
- the segregation layer in the ingot is not homogenized, the structure after hot working becomes a non-uniform recrystallized structure, and the final surface quality similarly decreases.
- the heating temperature of the homogenization treatment is higher than 580 ° C., the ingot may be locally melted, so that substantial manufacture becomes difficult.
- the heating temperature for the homogenization treatment is more than 540 ° C. and not more than 580 ° C.
- the Al—Zr-based compound present in the ingot changes to an equilibrium phase having a D0 23 type structure, becomes an equigranular recrystallized structure instead of a fibrous structure after hot working, and a grain boundary This prevents the recrystallization grains from coarsening.
- the heating time of the homogenization treatment is set to 1 hour or more and 24 hours or less.
- the aluminum alloy material includes, for example, an extruded material and a plate material made of an aluminum alloy.
- the present disclosure can be applied to various aluminum alloy materials and manufacturing methods thereof.
- Example 1 Examples in the aluminum alloy material of the present disclosure will be described using Tables 1 and 2 while being compared with Comparative Examples.
- the following example shows one embodiment of the present disclosure, and the present disclosure is not limited thereto.
- ⁇ Sample preparation method> By semi-continuous casting, a cylindrical ingot (billet) having a chemical component shown in Table 1 and having a diameter of 90 mm is cast. And the homogenization process which heats an ingot for 12 hours at 560 degreeC is performed. In addition, the heating temperature of a homogenization process can be 540 degreeC or more and 580 degrees C or less. Thereafter, the ingot is hot-extruded while maintaining the temperature of the ingot at 520 ° C. Thereby, an extruded material having a width of 150 mm and a thickness of 10 mm is obtained.
- a rapid cooling process is performed in which the extruded material after hot extrusion is cooled to 100 ° C. at a cooling rate of 1500 ° C./min. And after cooling the extruded material which performed the rapid cooling process to room temperature, the artificial aging process which heats an extruded material at 140 degreeC for 12 hours is performed. Thereby, a sample of an aluminum alloy material (extruded material) is obtained.
- a test piece is prepared from the sample by a method according to JIS Z2241 (ISO 6892-1), and the tensile strength, proof stress and elongation of the test piece are measured. Those whose proof stress is 300 MPa or more are determined to be acceptable. It should be noted that the criterion for the proof stress is merely an example.
- a test piece 10 having a thickness of 10 mm, a width of 10 mm, and a length of 120 mm is prepared from the central portion in the width direction of the sample, and the test piece 10 is bent by a three-point bending test.
- the amount of deformation ⁇ is measured.
- a jig having a base portion 11 and two fulcrum portions 12 is prepared, and the test piece 10 is placed on the two fulcrum portions 12.
- the test piece 10 is supported by the two fulcrum portions 12 at positions 10 mm from both ends of the test piece 10, and the distance between the fulcrums is set to 100 mm.
- a downward load in a direction perpendicular to the width direction of the sample is applied by an indenter 13 having a tip surface dimension of 10 mm ⁇ 10 mm.
- the amount of bending deformation ⁇ after applying a load of 4000 kgf for 10 seconds exceeds 4 mm, it is judged as “failed” “x”, and when it exceeds 2 mm and 4 mm or less, it is judged as “good” and 2 mm or less. In this case, a more preferable result “ ⁇ ” is determined.
- a Charpy impact test is performed by a method according to JIS Z2242. Specifically, a test piece having a thickness of 7.5 mm, a width of 10 mm, and a length of 55 mm is produced. The test piece has a U-notch having a depth of 2 mm formed such that its longitudinal direction is parallel to the extrusion direction and perpendicular to the extrusion direction. Then, a Charpy impact test is performed on the test piece, and the impact value is measured. When the impact value is 15 J / cm 2 or more, it is determined to be acceptable, and when it is less than 15 J / cm 2 , it is determined to be unacceptable. Note that the criterion for determining the impact value is merely an example.
- SCC resistance evaluation method An SCC test is performed by a method according to JIS Z8711. Specifically, a test piece having a C-ring shape (outer diameter 19 mm, inner diameter 16 mm, thickness 8 mm) is prepared. Then, a stress of 90% of the proof stress is applied to the test piece so that the tensile stress loading direction in the stress concentration portion coincides with the extrusion direction of the test piece. The step of immersing the piece in 3.5% salt water for 10 minutes and then drying for 50 minutes is repeated as one cycle. After 30 days, the test piece is visually checked for cracks. When the test piece is not cracked, it is determined to be acceptable, and when the test piece is cracked, it is determined to be unacceptable.
- the sample is a cross section parallel to the width direction when the processing direction (extruding direction in this case) is the length direction, and the structure is observed in the vicinity of the center in the width direction.
- the extruded material 20 as a sample is cut and subjected to electrolytic polishing on a total of three cross sections, ie, a central position cross section of the extruded material 20 and an upper and lower thickness 1 ⁇ 4 position cross section.
- a microscope image of each cross section for example, the photograph shown in the lower part of FIG. 2 at a magnification of 50 to 100 times.
- it is confirmed from the acquired microscopic image whether the metal structure is an equi-grain recrystallized structure. If the metal structure is fibrous, it is determined to be acceptable, and if the metal structure is not uniform, it is rejected. Is determined.
- the observation direction is the thickness direction of the sample as shown in FIG.
- the sample whose metal structure is a recrystallized structure having an equal granularity image analysis is performed on the acquired microscopic image to obtain the equivalent circle diameter of the crystal grains of each cross section, and the average grain diameter of the crystal grains for each cross section Is calculated. Further, the maximum diameter and the minimum diameter of the crystal grains are obtained for each cross section, and among the maximum diameter and the minimum diameter, the largest is the maximum value, the smallest is the minimum value, The difference (particle size difference) from the minimum value is calculated.
- the average particle size of the crystal grains in each cross section is 500 ⁇ m or less, and the difference between the maximum and minimum crystal grain sizes in all the observed cross sections (grain size difference) is preferably less than 300 ⁇ m. judge.
- ⁇ Surface quality evaluation method> The surface of the sample is mechanically polished (buffed), then etched with an aqueous sodium hydroxide solution, and further desmutted.
- the sample after desmut treatment is subjected to chemical polishing for 1 minute at a temperature of 90 ° C. using a phosphoric acid-nitric acid method.
- the chemically polished sample is anodized at a current density of 150 A / m 2 in a 15% concentration sulfuric acid bath to form an anodized film having a thickness of 10 ⁇ m.
- the sample after the anodizing treatment is immersed in boiling water, and the sealing treatment of the anodized film is performed. In this way, the sample is subjected to surface treatment (anodizing treatment).
- the surface of the sample after the surface treatment is visually observed.
- vertical with respect to the sample surface and it determines with what does not show surface defects, such as a scale-like pattern, a streaky pattern, a spot-like pattern, and a spot-like defect, on the sample surface.
- the sample is observed from the direction of 30 ° from the sample surface, and a light reflection state on the sample surface that is uniform is determined as a more preferable result.
- the scale pattern is a result of etching the compound precipitated on the grain boundary during the pretreatment of the surface treatment when the metal structure is an equi-grain recrystallized structure. It is a pattern that looks like a scale (a crystal grain looks more prominent).
- a streak pattern is a pattern that appears as a streak along a grain boundary as a result of etching of a compound deposited on the grain boundary during the pretreatment of the surface treatment when the metal structure is a fibrous structure. .
- the spotted pattern is a pattern in which the crystal grains are partially coarse and fine due to different crystal grain sizes, and large and small crystal grains appear mottled after the surface treatment.
- the dot-like defect is a pattern in which a concave depression is formed at a location where the compound is present, such as the coarse compound is removed by etching the coarse compound, and this appears to be a dot after surface treatment.
- Table 2 shows the evaluation results of each sample. In addition, in each sample, about the evaluation result etc. which were not determined to be acceptable (determined to be unacceptable), the evaluation results in Table 2 were underlined.
- Samples 1 to 23 are recrystallized structures with an equal grain metal structure, mechanical properties (proof stress, bending test), toughness (impact value), SCC resistance (stress corrosion cracking).
- all the evaluation items of metal structure observation metal structure, average particle diameter, particle size difference) and surface quality (defect after surface treatment, light reflection state) passed or passed, and more preferable results were obtained. That is, it showed excellent properties in terms of strength, toughness and surface quality, and also showed excellent properties in terms of SCC resistance.
- Sample 24 had a Zn content that was too low, so that a sufficient strength improvement effect was not obtained, and the yield strength was not acceptable.
- the sample 25 had a high Zn content, so that the hot workability was poor, and hot extrusion was difficult with substantial equipment.
- Sample 26 had a Mg content that was too low, so that the effect of improving the strength was not sufficiently obtained, and the yield strength was unacceptable.
- Sample 27 since the Mg content is too high, coarse compounds exist on the grain boundaries, scale-like patterns appear on the surface after the anodizing treatment, defects after the surface treatment are recognized, and the sample is rejected. there were.
- Sample 33 since the Mn content was too high, a fibrous structure was formed, a streak pattern was generated on the surface after the anodizing treatment, defects after the surface treatment were observed, and the sample 33 was rejected.
- Sample 34 the Cr content was too high, so that a fibrous structure was formed, a streak pattern was generated on the surface after the anodizing treatment, defects after the surface treatment were observed, and the sample 34 was rejected.
- Sample 27 Sample 29 to Sample 36, in which the defects after the surface treatment were unacceptable, were non-uniform in terms of light reflection status. Since the mass ratio (Zn / Mg) of Sample 37 was too low, the impact value was less than 15, and the impact value (toughness) was unacceptable. On the other hand, since the sample 38 had a mass ratio (Zn / Mg) that was too high, stress corrosion cracking occurred in the SCC resistance test, and the stress corrosion cracking (SCC resistance) was rejected.
- Example 2 The Example in the manufacturing method of the said aluminum alloy material is demonstrated using Table 3 and Table 4, contrasting with a comparative example.
- Table 3 The Example in the manufacturing method of the said aluminum alloy material is demonstrated using Table 3 and Table 4, contrasting with a comparative example.
- Table 4 The following example shows one embodiment of the present disclosure, and the present disclosure is not limited thereto.
- Example 3 a plurality of samples (Example: Sample A to Sample H, Comparative Example: Sample I to Sample N) were prepared by changing the production conditions of the aluminum alloy material. Evaluation was performed.
- the chemical composition of the aluminum alloy material was the same as that of Sample 10 or Sample 11 (see Table 1) of Example 1 described above.
- a method for manufacturing the sample will be described.
- Various evaluation methods are the same as those in Example 1 described above.
- Example preparation method By semi-continuous casting, a cylindrical ingot (billet) having a diameter of 90 mm having the same chemical composition as that of the sample 10 or the sample 11 (see Table 1) of Example 1 described above is cast. And the homogenization process which heats an ingot at the temperature and time which are shown in Table 3 is performed. Thereafter, the ingot is hot-extruded in a state where the temperature of the ingot is 520 ° C. Thereby, an extruded material having a width of 150 mm and a thickness of 10 mm is obtained.
- a rapid cooling process is performed in which the extruded material after hot extrusion is cooled to 100 ° C. at a cooling rate of 1500 ° C./min. And the temperature of the extrusion material which performed the rapid cooling process is cooled to room temperature, and the artificial aging treatment which heats at the temperature of 140 degreeC for 12 hours is performed. Thereby, a sample of an aluminum alloy material (extruded material) is obtained.
- Sample A to Sample H are recrystallized structures with an equal grain metal structure, mechanical properties (proof stress, bending test), toughness (impact value), SCC resistance (stress corrosion cracking).
- metal structure observation metal structure, average particle size, particle size difference
- surface quality defect after surface treatment, light reflection state
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Extrusion Of Metal (AREA)
- Continuous Casting (AREA)
Abstract
Description
20…試料
Zn:
Znは、Mgと共存してη’相を析出し、強度を向上させる効果がある。Zn含有量の範囲は、6.5%超え8.5%以下である。Zn含有量が6.5%以下の場合には、η’相の析出量が少なくなるため、強度向上の効果が小さくなる。一方、Zn含有量が8.5%を超える場合には、熱間加工性が低下するため、生産性が低下する。Zn含有量の好ましい範囲は、7.0%以上8.0%以下である。
Mgは、Znと共存してη’相を析出し、強度を向上させる効果がある。Mg含有量の範囲は、0.5%以上1.5%以下である。特に、Mg含有量の上限を1.5%以下に規制することにより、強度向上の効果を得ながら、粒界(結晶粒界、亜粒界等)上への化合物の析出を抑制できる。そのため、陽極酸化処理等の表面処理の際に、粒界上に析出した化合物が前処理時にエッチングされる量を低減し、表面処理後における表面の鱗状模様の発生を抑制できる。
Cuは、アルミニウム合金材の原料としてリサイクル材を使用する場合に混入する可能性がある。7000系アルミニウム合金において、Cuの含有は強度向上に寄与する一方、陽極酸化処理等の表面処理によって表面の色調が黄色味を帯びるといった色調変化等が生じ、表面品質が低下する原因となり得る。したがって、特に表面処理後の表面の色調が重要視される場合、Cu含有量の上限を規制する必要がある。そこで、Cu含有量の上限を0.10%以下に規制することにより、上述した表面品質の低下を抑制できる。Cu含有量は、0.08%以下であることが好ましい。
Fe、Siは、アルミニウム地金の不純物として混入する可能性がある。Mn、Crは、アルミニウム合金材の原料としてリサイクル材を使用する場合に混入する可能性がある。上記4成分のうち、Fe、Si、Mnは、Alとの間にAl-Mn系、Al-Mn-Fe系、Al-Mn-Fe-Si系の金属間化合物を形成することにより、再結晶化を抑制する作用を有する。また、Crは、Alとの間にAl-Cr系の金属間化合物を形成することにより、再結晶化を抑制する作用を有する。そのため、上記4成分の含有により、再結晶組織の形成が抑制され、その代わりに繊維状組織が形成される。
Zrは、微細かつ均一な再結晶組織を得るために添加される。Zr含有量の範囲は、0.05%以上0.10%以下である。ZrはAlとの間に微細なAl-Zr系化合物を形成する。このAl-Zr系化合物は、アルミニウム合金材の製造過程において、鋳塊の均質化処理の温度によって結晶構造が変化する。均質化処理の温度が540℃以下の場合には、母相と整合なL12型構造を有する準安定相が生成し、熱間加工後の組織において再結晶を抑制して繊維状組織となりやすい。一方、540℃超え580℃以下の温度で均質化処理を行うことで、Al-Zr系化合物は、D023型構造を有する平衡相に変化し、熱間加工後に繊維状組織ではなく等粒状の再結晶組織になると共に、結晶粒界の移動を妨げることで再結晶粒の粗大化を抑制する。
Tiは、鋳塊結晶粒の微細化を図るために添加する。Ti含有量の範囲は、0.001%以上0.05%以下である。Ti含有量が0.001%未満の場合には、結晶粒微細化効果が小さくなるため、陽極酸化処理等の表面処理後の表面に斑状模様が発生しやすくなり、表面品質が低下する。一方、Ti含有量が0.05%を超える場合には、Alとの間に形成されるAl-Ti系の金属間化合物等が原因となって表面処理後の表面に点状欠陥が発生しやすくなり、表面品質が低下する。
上記元素の他は、基本的にはAl及び不可避的不純物とすればよい。一般的にアルミニウム合金に添加される上記元素以外の元素は、不可避的不純物として、特性に大きな影響を与えない範囲内で許容される。
本開示のアルミニウム合金材における実施例について、比較例と対比しながら、表1及び表2を用いて説明する。以下に示す実施例は、本開示の一実施態様を示すものであり、本開示は何らこれらに限定されるものではない。
半連続鋳造により、表1に示す化学成分を有する、直径90mmの円柱状の鋳塊(ビレット)を鋳造する。そして、鋳塊を560℃で12時間加熱する均質化処理を行う。なお、均質化処理の加熱温度は、540℃超え580℃以下とすることができる。その後、鋳塊の温度を520℃に維持した状態で、鋳塊を熱間押出加工する。これにより、幅150mm、厚さ10mmの押出材を得る。
JIS Z2241(ISO 6892-1)に準拠する方法により、試料から試験片を作製し、その試験片の引張強さ、耐力及び伸びを測定する。耐力が300MPa以上であるものを合格と判定する。なお、耐力の判定基準はあくまでも一例である。
JIS Z2242に準拠する方法により、シャルピー衝撃試験を行う。具体的には、厚さ7.5mm、幅10mm、長さ55mmの試験片を作製する。試験片は、その長手方向が押出方向に平行であり、かつ、押出方向に直交するように形成された深さ2mmのUノッチを有する。そして、試験片に対してシャルピー衝撃試験を行い、衝撃値を測定する。衝撃値が15J/cm2以上の場合には合格と判定し、15J/cm2未満の場合には不合格と判定する。なお、衝撃値の判定基準はあくまでも一例である。
JIS Z8711に準拠する方法により、SCC試験を行う。具体的には、Cリング形状(外径19mm、内径16mm、厚さ8mm)の試験片を作製する。そして、応力集中部における引張応力の負荷方向が試験片の押出方向と一致するように、試験片に対して耐力の90%の応力を負荷し、その状態で25℃の温度環境の下、試験片を3.5%濃度の塩水に10分間浸漬した後、50分間乾燥させるという工程を1サイクルとして繰り返し行う。30日後、試験片に割れが発生していないか目視で確認する。試験片に割れが発生していない場合には合格と判定し、試験片に割れが発生している場合には不合格と判定する。
試料について、加工方向(ここでは押出方向)を長さ方向とした場合の幅方向に平行な断面であり、かつ幅方向中央付近部分の組織観察を行う。図2に示すように、試料である押出材20を切断し、押出材20の厚さ中央位置断面及び上下の厚さ1/4位置断面の計3つの断面について、電解研磨した後、偏光顕微鏡により倍率50~100倍で各断面の顕微鏡像(例えば図2下段に示す写真)を取得する。そして、取得した顕微鏡像から金属組織が等粒状の再結晶組織であるかを確認し、金属組織が繊維状である場合には合格と判定し、金属組織が不均一である場合には不合格と判定する。観察方向は、図2に示すように、試料の厚さ方向である。
試料の表面を機械的研磨(バフ研磨)した後、水酸化ナトリウム水溶液によりエッチングを行い、さらにデスマット処理を行う。そして、デスマット処理後の試料をリン酸-硝酸法を用いて90℃の温度で1分間の化学研磨を行う。
試料29は、Zr含有量が低すぎるため、粗大で不均一な再結晶組織となって陽極酸化処理後の表面に斑状模様が発生し、表面処理後の欠陥が認められ、不合格であった。一方、試料30は、Zr含有量が高すぎるため、繊維状組織が形成され、陽極酸化処理後の表面に筋状模様が発生し、表面処理後の欠陥が認められ、不合格であった。
試料32は、Fe含有量が高すぎるため、繊維状組織が形成され、陽極酸化処理後の表面に筋状模様が発生し、表面処理後の欠陥が認められ、不合格であった。
試料34は、Cr含有量が高すぎるため、繊維状組織が形成され、陽極酸化処理後の表面に筋状模様が発生し、表面処理後の欠陥が認められ、不合格であった。
試料37は、質量比(Zn/Mg)が低すぎるため、衝撃値が15未満となり、衝撃値(靱性)が不合格であった。一方、試料38は、質量比(Zn/Mg)が高すぎるため、耐SCC性試験において応力腐食割れが発生し、応力腐食割れ(耐SCC性)が不合格であった。
上記アルミニウム合金材の製造方法における実施例について、比較例と対比しながら、表3及び表4を用いて説明する。以下に示す実施例は、本開示の一実施態様を示すものであり、本開示は何らこれらに限定されるものではない。
半連続鋳造により、上述した実施例1の試料10又は試料11(表1参照)と同様の化学成分を有する直径90mmの円柱状の鋳塊(ビレット)を鋳造する。そして、鋳塊を表3に示す温度及び時間で加熱する均質化処理を行う。その後、鋳塊の温度が520℃の状態で、鋳塊を熱間押出加工する。これにより、幅150mm、厚さ10mmの押出材を得る。
試料M及び試料Nは、均質化処理の時間が短すぎるため、熱間押出加工後の金属組織が不均一となって陽極酸化処理後の表面に斑状模様が発生し、表面処理後の欠陥が認められ、不合格であった。
Claims (3)
- アルミニウム合金材であって、
Zn:6.5%(質量%、以下同様)超え8.5%以下、Mg:0.5%以上1.5%以下、Cu:0.10%以下、Fe:0.30%以下、Si:0.30%以下、Mn:0.05%未満、Cr:0.05%未満、Zr:0.05%以上0.10%以下、Ti:0.001%以上0.05%以下を含有し、残部がAl及び不可避的不純物からなる化学成分を有し、
ZnとMgとの質量比(Zn/Mg)が5以上16以下であり、
金属組織が等粒状の再結晶組織よりなる、アルミニウム合金材。 - 前記再結晶組織は、加工方向に直交する方向に平行な断面における結晶粒の平均粒径が500μm以下であり、かつ、前記結晶粒の粒径の最大値と最小値との差が300μm未満である、請求項1に記載のアルミニウム合金材。
- 金属組織が等粒状の再結晶組織よりなるアルミニウム合金材の製造方法であって、
Zn:6.5%(質量%、以下同様)超え8.5%以下、Mg:0.5%以上1.5%以下、Cu:0.10%以下、Fe:0.30%以下、Si:0.30%以下、Mn:0.05%未満、Cr:0.05%未満、Zr:0.05%以上0.10%以下、Ti:0.001%以上0.05%以下を含有し、残部がAl及び不可避的不純物からなる化学成分を有し、ZnとMgとの質量比(Zn/Mg)が5以上16以下である鋳塊を作製し、
該鋳塊を540℃超え580℃以下の温度で1時間以上24時間以下加熱する均質化処理を行うことを含む、アルミニウム合金材の製造方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020187017112A KR20180081603A (ko) | 2015-11-20 | 2016-11-18 | 알루미늄 합금재 및 그 제조방법 |
US15/777,798 US20180347017A1 (en) | 2015-11-20 | 2016-11-18 | Aluminum alloy material and production method therefor |
CN201680067521.6A CN108291279B (zh) | 2015-11-20 | 2016-11-18 | 铝合金材料及其制造方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015227926A JP6954722B2 (ja) | 2015-11-20 | 2015-11-20 | アルミニウム合金材及びその製造方法 |
JP2015-227926 | 2015-11-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017086470A1 true WO2017086470A1 (ja) | 2017-05-26 |
Family
ID=58719170
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/084338 WO2017086470A1 (ja) | 2015-11-20 | 2016-11-18 | アルミニウム合金材及びその製造方法 |
Country Status (5)
Country | Link |
---|---|
US (1) | US20180347017A1 (ja) |
JP (1) | JP6954722B2 (ja) |
KR (1) | KR20180081603A (ja) |
CN (1) | CN108291279B (ja) |
WO (1) | WO2017086470A1 (ja) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112676550B (zh) * | 2019-10-17 | 2022-09-27 | 北京小米移动软件有限公司 | 铝合金构件加工方法 |
EP4306669A1 (en) * | 2021-08-02 | 2024-01-17 | Samsung Electronics Co., Ltd. | Aluminum alloy extruded material and electronic device housing comprising same |
CN113528908B (zh) * | 2021-08-03 | 2022-03-01 | 西安科技大学 | 一种耐腐蚀高强铝合金及其制备方法 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012246555A (ja) * | 2011-05-30 | 2012-12-13 | Kobe Steel Ltd | 筐体用7000系アルミニウム合金押出材 |
JP2013007085A (ja) * | 2011-06-23 | 2013-01-10 | Sumitomo Light Metal Ind Ltd | 高強度アルミニウム合金材およびその製造方法 |
JP2013122083A (ja) * | 2011-11-07 | 2013-06-20 | Sumitomo Light Metal Ind Ltd | 高強度アルミニウム合金材及びその製造方法 |
JP2014141728A (ja) * | 2013-01-25 | 2014-08-07 | Kobe Steel Ltd | 耐応力腐食割れ性に優れた7000系アルミニウム合金部材及びその製造方法 |
JP2015218336A (ja) * | 2014-05-13 | 2015-12-07 | 日本軽金属株式会社 | 曲げ性に優れた高耐力Al−Zn系アルミニウム合金製押出材 |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4977281B2 (ja) | 2005-09-27 | 2012-07-18 | アイシン軽金属株式会社 | 衝撃吸収性及び耐応力腐食割れ性に優れた高強度アルミニウム合金押出材及びその製造方法 |
JP2016160515A (ja) * | 2015-03-04 | 2016-09-05 | 株式会社神戸製鋼所 | アルミニウム合金板 |
-
2015
- 2015-11-20 JP JP2015227926A patent/JP6954722B2/ja active Active
-
2016
- 2016-11-18 WO PCT/JP2016/084338 patent/WO2017086470A1/ja active Application Filing
- 2016-11-18 CN CN201680067521.6A patent/CN108291279B/zh not_active Expired - Fee Related
- 2016-11-18 KR KR1020187017112A patent/KR20180081603A/ko not_active Application Discontinuation
- 2016-11-18 US US15/777,798 patent/US20180347017A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012246555A (ja) * | 2011-05-30 | 2012-12-13 | Kobe Steel Ltd | 筐体用7000系アルミニウム合金押出材 |
JP2013007085A (ja) * | 2011-06-23 | 2013-01-10 | Sumitomo Light Metal Ind Ltd | 高強度アルミニウム合金材およびその製造方法 |
JP2013122083A (ja) * | 2011-11-07 | 2013-06-20 | Sumitomo Light Metal Ind Ltd | 高強度アルミニウム合金材及びその製造方法 |
JP2014141728A (ja) * | 2013-01-25 | 2014-08-07 | Kobe Steel Ltd | 耐応力腐食割れ性に優れた7000系アルミニウム合金部材及びその製造方法 |
JP2015218336A (ja) * | 2014-05-13 | 2015-12-07 | 日本軽金属株式会社 | 曲げ性に優れた高耐力Al−Zn系アルミニウム合金製押出材 |
Also Published As
Publication number | Publication date |
---|---|
US20180347017A1 (en) | 2018-12-06 |
JP6954722B2 (ja) | 2021-10-27 |
JP2017095754A (ja) | 2017-06-01 |
CN108291279B (zh) | 2020-08-04 |
CN108291279A (zh) | 2018-07-17 |
KR20180081603A (ko) | 2018-07-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5285170B2 (ja) | 高強度アルミニウム合金材及びその製造方法 | |
JP5023232B1 (ja) | 高強度アルミニウム合金材およびその製造方法 | |
JP4753240B2 (ja) | 高強度アルミニウム合金材ならびに該合金材の製造方法 | |
WO2015025706A1 (ja) | 高強度アルミニウム合金及びその製造方法 | |
WO2015146654A1 (ja) | アルミニウム合金鍛造材およびその製造方法 | |
JP6022882B2 (ja) | 高強度アルミニウム合金押出材及びその製造方法 | |
WO2017169962A1 (ja) | 耐食性に優れ、良好な焼入れ性を有する高強度アルミニウム合金押出材及びその製造方法 | |
CN106893900B (zh) | 汽车用铝合金锻造材 | |
JP6119937B1 (ja) | 陽極酸化皮膜を有する外観品質に優れたアルミニウム合金押出材及びその製造方法 | |
KR101838469B1 (ko) | 고강도 알루미늄 합금 및 이의 제조 방법 | |
JP5023233B1 (ja) | 高強度アルミニウム合金材およびその製造方法 | |
JP2016027194A (ja) | アルミニウム合金圧延材 | |
WO2017086470A1 (ja) | アルミニウム合金材及びその製造方法 | |
JP2009167464A (ja) | 靱性に優れたアルミニウム合金材の製造方法 | |
JP7172833B2 (ja) | アルミニウム合金材及びその製造方法 | |
WO2017006816A1 (ja) | 陽極酸化皮膜を有する外観品質に優れたアルミニウム合金押出材及びその製造方法 | |
JP6291133B2 (ja) | アルミニウム合金材 | |
JP2013007114A (ja) | 陽極酸化処理用高強度アルミニウム合金材 | |
JP2023126137A (ja) | 良好な焼入れ性を有し、高靱性及び高強度のアルミニウム合金押出材の製造方法 | |
JP2007077415A (ja) | 円錐台張出成形用アルミニウム合金板の製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 16866470 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 20187017112 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020187017112 Country of ref document: KR |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 16866470 Country of ref document: EP Kind code of ref document: A1 |