NON-HEAT TREATED ALUMINUM ALLOY STRESS-BEARING MEMBER MATERIAL WITH HIGH TOUGHNESS AND HIGH CASTING PERFORMANCE AND PREPARATION METHOD THEREOF

Abstract

The present disclosure relates to the technical field of metal materials, and more specifically, to a non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance and its preparation method. The non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance includes the following components in terms of mass percentage: Si: 8.5-12.0%, Mg: 0.10-0.35%, Mn: 0.25-0.4%, Cr: 0.02-0.14%, V: 0.02-0.38%, Sr: 0.01-0.04%, Ti: 0.05-0.11%, B≤0.005%, Ca≤0.05%, Zr≤0.1%, Zn≤0.1%, RE≤0.1%. The total amount of other impurities is less than or equal to 0.25%, and the balance is Al. Under the premise of ensuring that the alloy has good die casting performance, the die-casting parts in non-heat-treated state can have excellent comprehensive mechanical properties, thereby meeting the performance requirements of the die casting stress-bearing member.

Claims

1. A non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance, comprising the following components in terms of mass percentage: Si: 8.5-12.0%, Mg: 0.10-0.35%, Mn: 0.25-0.4%, Cr: 0.02-0.14%, V: 0.02-0.38%, Sr: 0.01-0.04%, Ti: 0.05-0.11%, B≤0.005%, Ca≤0.05%, Zr≤0.1%, Zn≤0.1%, RE≤0.1%; a total amount of other impurities is less than or equal to 0.25%, and the balance is Al.

2. The non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance of claim 1, wherein the RE element is selected from one or a mixture of La, Ce and Sc elements.

3. The non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance of claim 1, wherein a tensile strength of the aluminum alloy material is not less than 260 MPa, a yield strength is not less than 140 MPa, and an elongation is not less than 12%.

4. A preparation method of the non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance of claim 1, comprising the following steps: S1 pretreatment: cutting Al—Si, Al—Mn, Al—Cr, Al—V, Al—Sr, Al—Ti, Al—Ti—B, Al—Ca, Al—Zr, Al—Zn, Al—RE master alloy ingots and pure Al and pure Mg ingots, grinding and polishing to remove oxide scale on the surface, and weighing the same; S2 melting: setting a temperature of a crucible furnace and keeping the temperature stable, placing pure Al and Al—Si master alloy in the crucible furnace, obtaining a molten metal after the pure Al and Al—Si master alloy are completely melted, adding Al—Cr, Al—Mn, Al—Ti, Al—Ca, Al—Zn master alloys and pure Mg into the molten metal, reducing a temperature of a molten aluminum for the first time after complete melting, adding remaining master alloys after the temperature is stable, preserving heat for 3-5 min, injecting high-purity argon into the molten metal for 10-12 min at a flow rate of 3-5 L/min with a vent nozzle is placed at a bottom of the molten metal, and leaving for 3-5 min after degassing to remove surface dross; and S3 casting: filtering the molten metal after the temperature of the molten aluminum is reduced for the second time, and pouring the filtered molten metal into a mold preheated to 150-180° C., with a casting cycle of 35-55 s.

5. The preparation method of claim 4, wherein the temperature of the crucible furnace is 730˜755° C.

6. The preparation method of claim 4, wherein the temperature of the molten aluminum is reduced to 700˜ 720° C. for the first time.

7. The preparation method of claim 4, wherein the temperature of the molten aluminum is reduced to 650-690° C. for the second time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to explain the embodiments of the present disclosure or the technical solutions in the prior art more clearly, the following drawings that need to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on the drawings disclosed without creative work.

[0026] FIG. 1 is a picture of the microstructure of the non-heat treated aluminum alloy material in the as-cast in test experiment 1 of the present disclosure.

[0027] FIG. 2 is a flow test result chart of test experiment 2 of the present disclosure.

[0028] FIG. 3 is the microstructure picture after heat treatment at 500° C. for 2 h of test experiment 3 of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Technical solutions of the present disclosure will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of them. Other embodiments made by those skilled in the art without sparing any creative effort should fall within the scope of the disclosure.

[0030] The term “embodiment” used herein as an example does not necessarily mean that any embodiment described as “exemplary” is superior to or better than other embodiments. Unless otherwise specified, the performance index test in the embodiments of the application adopts the conventional test methods in the art. It should be understood that the terms described in this application are only for describing special embodiments and are not used to limit the contents disclosed in this application.

[0031] Unless otherwise specified, the technical and scientific terms used herein have the same meanings generally understood by those of ordinary skill in the art to which the application belongs.

[0032] Other unspecified test methods and technical means in this application refer to the test methods and technical means commonly used by ordinary technicians in the art.

[0033] The terms “basically” and “approximately” used in this application are used to describe small fluctuations. They may refer to, for example, less than or equal to ±5%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.2%, less than or equal to ±0.1% or less than or equal to ±0.05%. The numerical data expressed or presented in the range format in this application is only used for convenience and brevity, so it should be flexibly interpreted to include not only the numerical values explicitly listed as the boundaries of the range, but also all independent numerical values or sub ranges included in the range. For example, the numerical range of “1˜5%” should be interpreted to include not only explicitly enumerated values of 1% to 5%, but also independent values and sub ranges within the exemplary range. Therefore, this numerical range includes independent values, such as 2%, 3.5% and 4%, and sub ranges, such as 1%˜3%, 2%˜4% and 3%˜5%. This principle is also applicable to the range in which only one numerical value is listed. In addition, such an explanation applies regardless of the width of the range or the features.

[0034] In order to better illustrate the content of the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application may be practiced without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. that are well known to those skilled in the art are not described in detail, so as to highlight the gist of the present application.

[0035] The technical features disclosed in the embodiments of the present application may be arbitrarily combined on the premise of no conflict, and the obtained technical solution belongs to the content disclosed in the embodiments of the present application.

Embodiment 1

[0036] A non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance is provided.

[0037] Mass percentage of each component element in the target alloy is as follows. Si: 10.5%, Mg: 0.18%, Mn: 0.3%, Cr: 0.08%, V: 0.12%, Sr: 0.025%, Ti: 0.09%, B: 0.002%, Ca: 0.02%, Zr: 0.06%, RE: 0.02%, and the balance is Al.

[0038] The Preparation Method Includes the Following Steps.

[0039] (1) Pretreatment: Al—Si, Al—Mn, Al—Cr, Al—V, Al—Sr, Al—Ti, Al—Ti—B, Al—Ca, Al—Zr, Al—RE master alloy ingots and pure Al and pure Mg ingots are cut, ground and polished to remove oxide scale on the surface, and then weighed.

[0040] (2) Melting: A temperature of a crucible furnace is set as 740° C. and kept stable, then pure Al and Al—Si master alloy are placed in the crucible furnace to obtain a molten metal after the pure Al and Al—Si master alloy are completely melted. Al—Cr, Al—Mn, Al—Ti, Al—Ca, Al—Zn master alloys and pure Mg are added into the molten metal. The temperature of a molten aluminum is reduced to 700° C. for after complete melting. Then the remaining master alloys are added after the temperature is stable.

[0041] After preserving heat for 5 min, high-purity argon is injected into the molten metal for 12 min at a flow rate of 4 L/min with a vent nozzle is placed at a bottom of the molten metal. After degassing, it is allowed to stand for 5 min to remove surface dross.

[0042] (3) Casting: The molten metal is filtered after the temperature of the molten aluminum is reduced to 660° C., and the filtered molten metal is poured into a mold preheated to 160° C., with a casting cycle of 35 s.

Embodiment 2

[0043] A non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance is provided.

[0044] Mass percentage of each component element in the target alloy is as follows. Si: 8.5%, Mg: 0.35%, Mn: 0.4%, Cr: 0.02%, V: 0.38%, Sr: 0.01%, Ti: 0.09%, B: 0.005%, Ca: 0.05%, Zr: 0.1%, Zn: 0.08%, RE: 0.02%, and the balance is Al.

[0045] The Preparation Method Includes the Following Steps.

[0046] (1) Pretreatment: Al—Si, Al—Mn, Al—Cr, Al—V, Al—Sr, Al—Ti, Al—Ti—B, Al—Ca, Al—Zr, Al—Zn, Al—RE master alloy ingots and pure Al and pure Mg ingots are cut, ground and polished to remove oxide scale on the surface, and then weighed.

[0047] (2) Melting: A temperature of a crucible furnace is set as 730° C. and kept stable, then pure Al and Al—Si master alloy are placed in the crucible furnace to obtain a molten metal after the pure Al and Al—Si master alloy are completely melted. Al—Cr, Al—Mn, Al—Ti, Al—Ca, Al—Zn master alloys and pure Mg are added into the molten metal. The temperature of a molten aluminum is reduced to 720° C. after complete melting. Then the remaining master alloys are added after the temperature is stable. After preserving heat for 5 min, high-purity argon is injected into the molten metal for 12 min at a flow rate of 3 L/min with a vent nozzle is placed at a bottom of the molten metal. After degassing, it is allowed to stand for 3 min to remove surface dross.

[0048] (3) Casting: The molten metal is filtered after the temperature of the molten aluminum is reduced to 650° C., and the filtered molten metal is poured into a mold preheated to 170° C., with a casting cycle of 40 s.

Embodiment 3

[0049] A non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance is provided.

[0050] Mass percentage of each component element in the target alloy is as follows. Si: 12%, Mg: 0.1%, Mn: 0.3%, Cr: 0.14%, V: 0.02%, Sr: 0.025%, Ti: 0.11%, Ca: 0.05%, Zr: 0.06%, Zn: 0.1%, RE: 0.02%, and the balance is Al.

[0051] The Preparation Method Includes the Following Steps.

[0052] (1) Pretreatment: Al—Si, Al—Mn, Al—Cr, Al—V, Al—Sr, Al—Ti, Al—Ti—B, Al—Ca, Al—Zr, Al—Zn, Al—RE master alloy ingots and pure Al and pure Mg ingots are cut, ground and polished to remove oxide scale on the surface, and then weighed.

[0053] (2) Melting: A temperature of a crucible furnace is set as 755° C. and kept stable, then pure Al and Al—Si master alloy are placed in the crucible furnace to obtain a molten metal after the pure Al and Al—Si master alloy are completely melted. Al—Cr, Al—Mn, Al—Ti, Al—Ca, Al—Zn master alloys and pure Mg are added into the molten metal. The temperature of a molten aluminum is reduced to 700° C. after complete melting. Then the remaining master alloys are added after the temperature is stable. After preserving heat for 3 min, high-purity argon is injected into the molten metal for 10 min at a flow rate of 5 L/min with a vent nozzle is placed at a bottom of the molten metal. After degassing, it is allowed to stand for 5 min to remove surface dross.

[0054] (3) Casting: The molten metal is filtered after the temperature of the molten aluminum is reduced to 690° C., and the filtered molten metal is poured into a mold preheated to 180° C., with a casting cycle of 55 s.

Embodiment 4

[0055] A non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance is provided.

[0056] Mass percentage of each component element in the target alloy is as follows. Si: 9%, Mg: 0.2%, Mn: 0.25%, Cr: 0.14%, V: 0.2%, Sr: 0.04%, Ti: 0.05%, B: 0.002%, Zr: 0.06%, Zn: 0.08%, RE: 0.1%, and the balance is Al.

[0057] The Preparation Method Includes the Following Steps.

[0058] (1) Pretreatment: Al—Si, Al—Mn, Al—Cr, Al—V, Al—Sr, Al—Ti, Al—Ti—B, Al—Zr, Al—Zn, Al—RE master alloy ingots and pure Al and pure Mg ingots are cut, ground and polished to remove oxide scale on the surface, and then weighed.

[0059] (2) Melting: A temperature of a crucible furnace is set as 740° C. and kept stable, then pure Al and Al—Si master alloy are placed in the crucible furnace to obtain a molten metal after the pure Al and Al—Si master alloy are completely melted. Al—Cr, Al—Mn, Al—Ti, Al—Ca, Al—Zn master alloys and pure Mg are added into the molten metal. The temperature of a molten aluminum is reduced to 700° C. after complete melting. Then the remaining master alloys are added after the temperature is stable. After preserving heat for 5 min, high-purity argon is injected into the molten metal for 12 min at a flow rate of 5 L/min with a vent nozzle is placed at a bottom of the molten metal. After degassing, it is allowed to stand for 5 min to remove surface dross.

[0060] (3) Casting: The molten metal is filtered after the temperature of the molten aluminum is reduced to 660° C., and the filtered molten metal is poured into a mold preheated to 160° C., with a casting cycle of 35 s.

[0061] In order to further prove the beneficial effects of the present disclosure and better understand the present disclosure, the performance and preparation method of the non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance disclosed in the present disclosure are further explained by the following comparative examples, but they are not intended to limit the disclosure. The product properties obtained from other comparative experiments made by those skilled in the art according to the above disclosure and the applications made according to the above properties are also considered to fall within the protection scope of the present disclosure.

Comparative Example 1

[0062] Mass percentage of each component element in the target alloy is as follows. Si: 10.5%, Mg: 0.18%, Mn: 0.65%, Sr: 0.025%, Ti: 0.09%, B: 0.002%, Ca: 0.02%, Zr: 0.06%, RE: 0.02%, and the balance is Al.

[0063] The preparation method includes the following steps.

[0064] (1) Pretreatment: Al—Si, Al—Mn, Al—Cr, Al—V, Al—Sr, Al—Ti, Al—Ti—B, Al—Ca, Al—Zr, Al—Zn, Al—RE master alloy ingots and pure Al and pure Mg ingots are cut, ground and polished to remove oxide scale on the surface, and then weighed.

[0065] (2) Melting: A temperature of a crucible furnace is set as 740° C. and kept stable, then pure Al and Al—Si master alloy are placed in the crucible furnace to obtain a molten metal after the pure Al and Al—Si master alloy are completely melted. Al—Cr, Al—Mn, Al—Ti, Al—Ca, Al—Zn master alloys and pure Mg are added into the molten metal. The temperature of a molten aluminum is reduced to 700° C. after complete melting. Then the remaining master alloys are added after the temperature is stable. After preserving heat for 5 min, high-purity argon is injected into the molten metal for 12 min at a flow rate of 4 L/min with a vent nozzle is placed at a bottom of the molten metal. After degassing, it is allowed to stand for 5 min to remove surface dross.

[0066] (3) Casting: The molten metal is filtered after the temperature of the molten aluminum is reduced to 660° C., and the filtered molten metal is poured into a mold preheated to 160° C., with a casting cycle of 35 s.

[0067] In order to further prove the beneficial effects of the present disclosure and better understand the present disclosure, the performance of the non-heat treated aluminum alloy stress-bearing member material with high toughness and high casting performance disclosed in the present disclosure are further explained by the following test experiment and experimental data, but they are not intended to limit the disclosure. The product properties obtained from other comparative experiments made by those skilled in the art according to the above disclosure and the applications made according to the above properties are also considered to fall within the protection scope of the present disclosure.

[0068] Test Experiment 1

[0069] The test samples were obtained from the materials obtained in embodiment 1 and comparative example 1 at the same position, and the test samples were inlaid, ground, and polished to obtain the metallographic sample blocks. The metallographic sample blocks were observed with a metallographic microscope, and the microstructure pictures were obtained. The results are shown in FIG. 1.

[0070] As can be seen from FIG. 1a and FIG. 1b, the secondary dendrite spacing in embodiment 1 is smaller than that in comparative example 1. From FIG. 1c and FIG. 1d (partial enlarged views of FIG. 1a and FIG. 1b), it is more obvious that there is a difference in the formation phase between the two dendrites (the gray particles indicated by the red arrows are Fe containing phase). Embodiment 1 shows that the interdendritic Fe containing phase is basically in the form of small particles, while the Fe containing phase in comparative example has a large overall size and some of it is needle shaped, which will lead to stress concentration during the stress process of the alloy, thus reducing the alloy performance.

[0071] Test Experiment 2

[0072] The molten aluminum obtained in embodiment 1 and comparative example 1 was poured into a fluidity mold at the same temperature, and the fluidity detection results were obtained. The results are shown in FIG. 2.

[0073] According to the fluidity detection law, the longer the distance of molten aluminum flowing in the mold, the better the fluidity of the alloy, the better the casting performance, and the easier it is to fill the cavity in the casting process. The mold temperature used in high-pressure casting process is lower, which requires higher casting performance. The fluidity of the embodiment in the disclosure is much higher than that of the comparative example, and its casting performance is excellent.

[0074] Test Experiment 3

[0075] The materials obtained in embodiment 1 and comparative example 1 were simultaneously kept at a furnace temperature of 500° C. for 2 h, and test samples were obtained at the same positions of the heat-treated samples of the two alloy materials. The test samples were inlaid, ground, and polished to obtain metallographic sample blocks. The metallographic sample blocks were observed with a metallographic microscope, and the microstructure pictures after being treated at high temperature for a period of time were obtained. The results are shown in FIG. 3.

[0076] It can be seen from the figures that after the high-temperature treatment of 500° C.*2h, the secondary dendrite spacing of embodiment 1 is not much different from that of FIG. 1a, while the secondary dendrite spacing of comparative example is significantly increased compared with that of FIG. 1b. It shows that the grain size in embodiment 1 did not change significantly at high temperature, but that in the comparative example changed greatly. It is further explained that the structure of the alloy in embodiment 1 is relatively stable during service at high temperatures. This is mainly because Cr and SC elements and the generated second phase have thermal stability. During the high-temperature service of the material, they prevent the grain growth, stabilize the performance of the alloy, and expand the application field of this alloy in the future.

[0077] Test Experiment 4

[0078] The as-cast test bars obtained in embodiments 1 to 4 and comparative example 1 were tested for tensile mechanical properties at room temperature. The test bars were prepared into the standard test bars according to the national standard, and the tensile property of the material was tested at room temperature with a tensile tester. Five test bars per group were tested and averaged to obtain the data in Table 1

[0079] The test results show that embodiment 1 has the highest elongation and embodiment 4 has the best comprehensive performance according to the difference of the effects of various trace elements. The strength and elongation of comparative example 1 were generally worse than those of embodiment 1, because the elements added in embodiment 1 made the alloy grain finer, the size of the second phase between dendrites smaller, and the roundness higher, that is, the microstructure was more excellent.

TABLE-US-00001 TABLE 1 Test results of tensile mechanical properties at room temperature Performance Yield Tensile Group strength/Mpa strength/Mpa Elongation/% Embodiment 1 160.32 273.45 17.20 Embodiment 2 169.92 284.21 14.96 Embodiment 3 164.28 278.34 15.83 Embodiment 4 174.56 285.37 15.99 Comparative 142.81 255.47 10.12 example

[0080] The above description of the disclosed embodiments enables the skilled in the art to achieve or use the disclosure. Multiple modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be achieved in other embodiments without departing from the spirit or scope of the disclosure. The present disclosure will therefore not be restricted to these embodiments shown herein, but rather to comply with the broadest scope consistent with the principles and novel features disclosed herein.