A heat-resistant aluminum-silicon alloy material and its preparation method

Abstract

The present invention discloses a heat-resistant aluminum-silicon alloy material and a preparation method thereof, relating to the technical field of alloy materials. The heat-resistant aluminum-silicon alloy material includes an Al-12Si-1Cu-1Ni-1Mg matrix alloy and red mud chemically coated with Ni; by mass percentage, the red mud chemically coated with Ni is 0 wt.% to 2 wt.%, and the Al-12Si-1Cu-1Ni-1Mg alloy is 98 wt.% to 100 wt.%. The present invention uses mechanical stirring and electromagnetic stirring to add the Ni-coated red mud into the aluminum-silicon-copper-nickel-magnesium alloy, and the coating of Ni improves the wettability of the red mud and the base material. By adding different components of Ni-coated red mud to the alloy and after T6 heat treatment, the Vickers hardness of the matrix material, the tensile strength at room temperature, and the tensile strength at high temperature are significantly improved, solving the problem of weak tensile properties of traditional aluminum-silicon alloys in high-temperature environments.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and in particular to a heat-resistant aluminum-silicon alloy material and a preparation method thereof. Background Art

[0002] Red mud is the main solid waste generated in the production of alumina. This material is a composite composed of more than eight mineral components. It has the characteristics of uneven particle size distribution, strong water and moisture absorption, and strong alkaline corrosiveness. It is reddish brown due to its high proportion of iron oxide. This waste is loose in dry state, and hard and sticky when wet. In the past 50 years, no economically effective large-scale treatment or recycling method for red mud has been found. The global accumulated red mud stock has exceeded 4.6 billion tons, increasing at a rate of about 175.5 million tons per year. The global average utilization rate of red mud is only 15%, and the rest is often treated by stacking or landfilling. This treatment method leads to a significant reduction in land utilization and a significant increase in environmental pollution. How to economically and effectively deal with these large amounts of accumulated red mud is an unresolved global problem.

[0003] After years of development and exploration, red mud treatment technology is currently divided into three types: reduction, resource utilization and extraction. In the resource utilization of red mud, the key is to utilize its physical and chemical properties, develop its functional uses in multiple fields, and transform this by-product into a product with economic value, usually by combining red mud as an additive with other materials to form a composite material.

[0004] There are currently two main traditional methods for improving the high-temperature mechanical properties of aluminum alloys. The first method is to add high-melting-point second-phase particles to keep the second-phase particles at high temperatures sufficient, thereby maintaining high-temperature stability; but this method will reduce the plasticity of the material and limit its application as a structural material. The second method is to add a small amount of high-temperature resistant elements (such as Er, Sc, Zr, Ti, Mn, etc.) to the alloy, and form Al3X particles with good thermal stability during the preparation and solution treatment of the alloy to enhance the mechanical properties of the alloy. However, due to the low solubility of these elements, the volume fraction of Al3X particles is not high, and it is difficult to significantly improve the high-temperature resistance of the alloy, and the cost is too high to be used on a large scale in industrial production. In addition, the presence of Al3X particles will also reduce the plasticity of the material. In view of the above problems, the present invention proposes an Al-12Si-1Cu-1Ni-1Mg / red mud heat-resistant aluminum-silicon alloy material and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a heat-resistant aluminum-silicon alloy material and a preparation method thereof, to solve the problems raised in the above-mentioned background technology. By performing Ni coating treatment on the surface of red mud, the wettability between the oxides in the red mud and the alloy substrate is improved, thereby enhancing the bonding between the second-phase particles and the substrate alloy, effectively enhancing the high-temperature mechanical properties of the substrate alloy, and reducing costs at the same time.

[0006] To achieve the above purpose, the present invention provides a heat-resistant aluminum-silicon alloy material, including an Al-12Si-1Cu-1Ni-1Mg (ZL109) matrix alloy and red mud chemically coated with Ni; by mass percentage, among them, the red mud chemically coated with Ni is 0 wt.% to 2 wt.%, and the Al-12Si-1Cu-1Ni-1Mg alloy is 98 wt.% to 100 wt.%.

[0007] The present invention also provides a preparation method of the above-mentioned heat-resistant aluminum-silicon alloy material, including the following steps:

[0008] S1: Chemically coat Ni on the red mud after magnetic separation;

[0009] S2: Cut the massive aluminum-silicon alloy, aluminum-copper alloy, aluminum-nickel alloy, and aluminum-magnesium alloy into small pieces in a machine tool, and then dry for standby;

[0010] S3: Put industrial pure aluminum into a graphite crucible, place it in an electromagnetic induction furnace to heat and melt, add aluminum-silicon alloy, aluminum-copper alloy, and aluminum-nickel alloy to the melt, let it stand for heat preservation and then stir and skim the slag;

[0011] S4: After adjusting the temperature, press the aluminum-magnesium alloy into the bottom of the melt obtained in S2, add a refining agent after heat preservation, and skim the slag after all raw materials are melted;

[0012] S5: Stir and add the Ni-coated red mud obtained in S1, adjust the temperature and skim the slag to obtain an Al-12Si-1Cu-1Ni-1Mg / red mud alloy material melt;

[0013] S6: Pour the Al-12Si-1Cu-1Ni-1Mg / red mud alloy material melt into a mold, and demold to obtain an ingot of the Al-12Si-1Cu-1Ni-1Mg / red mud alloy material;

[0014] S7: Perform T6 heat treatment on the alloy material prepared in S6 to obtain the target product.

[0015] Preferably, the specific operation of S1 is:

[0016] S1-1: Perform drying treatment on the red mud after magnetic separation, grind it and add it to the NiSO4 solution for ultrasonic dispersion, stir, filter and then dry;

[0017] S1-2: Grind the red mud obtained in S1-1, then add it to a mixed solution of NaBH4, NaOH, and C6H5Na3O7 at 50 °C, stir, filter, wash with deionized water, and dry to obtain Ni-coated red mud.

[0018] Preferably, in S1-1, the concentration of the NiSO4 solution is 17.8 g·L -1 ; the ultrasonic time is 10 min; the stirring rate is 200 r / min, and the stirring time is 1 h;

[0019] In S1-2, the concentration of NaBH4 is 2 g·L -1 , the concentration of NaOH is 30 g·L -1 , the concentration of C6H5Na3O7 is 50 g·L -1 , the stirring rate is 200 r / min, and the stirring time is 10 min.

[0020] Preferably, in S2, the drying conditions are: drying in an electrothermal constant temperature blast drying oven at 200 °C for 0.5 h, where the heating rate of the drying oven is 5-10 °C / min.

[0021] Preferably, in S3, the temperature of the electromagnetic induction furnace is 720 °C; the static heat preservation time is 10 min; the mass ratio of the aluminum-silicon alloy, aluminum-copper alloy, and aluminum-nickel alloy is 12:1:1.

[0022] Preferably, in S4, the temperature is adjusted to 680-700 °C and held for 5 min; the refining agent is hexachloroethane.

[0023] Preferably, in S5, the stirring temperature is 710 °C, the stirring speed is 600 r / min, and the stirring time is 5 min; the temperature is adjusted to 720-730 °C to skim the slag.

[0024] Preferably, in S6, after the mold is coated with a sodium silicate / zinc oxide mixed coating with a mass ratio of 1:3, it is placed in a muffle furnace and preheated to 200 °C.

[0025] Preferably, the specific operation of S7 is: put the ingot into a muffle furnace and heat it to 515 °C with the furnace and hold for 8 h, then quench it in water at 90-100 °C to complete solid solution, then put the sample into the muffle furnace and heat it to 175 °C with the furnace and hold for 12 h, and then cool it to room temperature with the furnace to complete the T6 heat treatment.

[0026] Therefore, the present invention provides a heat-resistant aluminum-silicon alloy material and its preparation method, and the specific beneficial effects are as follows:

[0027] (1) The present invention uses mechanical stirring and electromagnetic stirring to add red mud coated with Ni into an aluminum-silicon-copper-nickel-magnesium alloy. The coating of Ni improves the wettability between the red mud and the base material. By adding red mud coated with Ni with different components to the alloy and after T6 heat treatment, the Vickers hardness, the tensile strength at room temperature, and the tensile strength at high temperature of the matrix material are significantly improved. The problem that traditional aluminum-silicon alloys have weak tensile properties in high-temperature environments is effectively solved.

[0028] (2) The present invention has low cost, involves shorter melting and cooling times, and is convenient for popularization and application in industrial production. It has broad application potential in the fields of new material development, high-temperature durable alloys, and resource recycling.

[0029] (3) The Vickers hardness of the ZL109 / red mud composite heat-resistant aluminum alloy in the T6 state increases with the increase of the red mud content and reaches the maximum when the addition amount reaches 1.5%. The Vickers hardness increases from 175.97 HV to 210.51 HV, an increase of 19.63%.

[0030] (4) The tensile strength at room temperature of the ZL109 / red mud composite heat-resistant aluminum alloy in the T6 state increases with the increase of the red mud content and reaches the maximum when 1% red mud is added. The tensile strength at room temperature increases from 265.8 HV to 295.4 HV, an increase of 11.1%.

[0031] (5) The tensile strength at high temperature of the ZL109 / red mud composite heat-resistant aluminum alloy in the T6 state at 350 °C increases with the increase of the red mud content and reaches the maximum when 1% red mud is added. The tensile strength at high temperature increases from 94.6 MPa to 143.3 MPa, an increase of 51.47%. The tensile strength at high temperature at 400 °C increases with the increase of the red mud content and reaches the maximum when 1.5% red mud is added. The tensile strength at high temperature can reach 86.2 MPa.

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0033] Figure 1 It is an XRD broken line graph of the ZL109 / red mud composite heat-resistant aluminum alloy in the T6 state;

[0034] Figure 2 It is a bar graph of the Vickers hardness of the ZL109 / red mud composite heat-resistant aluminum alloy in the T6 state;

[0035] Figure 3 It is a room temperature tensile curve graph of the ZL109 / red mud composite heat-resistant aluminum alloy in the T6 state;

[0036] Figure 4It is the high-temperature tensile curve graph of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy. Detailed implementation manners

[0037] The present invention will be further described below in conjunction with specific drawings and embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and shall be included within the protection scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application and belong to the protection scope of the present invention.

[0038] As used herein, "embodiment" means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The term "embodiment" appearing in various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0039] Unless otherwise defined, the meanings of the technical terms used herein are the same as those commonly understood by those skilled in the technical field to which this application belongs; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit this application.

[0040] Unless otherwise specified in the present invention, the reagents, instruments, equipment, etc. used are the reagents, instruments, and equipment commonly used by those skilled in the art in this field. The raw materials used in the present invention are industrial pure aluminum provided by Suzhou Guangyuan Metal Materials Co., Ltd., aluminum-silicon 50, aluminum-copper 50, aluminum-magnesium 20, aluminum-nickel 20 alloys provided by Suzhou Xinghai E-commerce Co., Ltd., and red mud provided by Guangxi Huayin Aluminum Co., Ltd. with Fe3O4 removed by strong magnetic separation.

[0041] Example 1

[0042] This example provides a preparation method for a 0.5wt.% ZL109 / red mud alloy material, including the following steps:

[0043] S1: Place the red mud after magnetic separation to remove Fe3O4 in an electrothermal constant temperature blast drying oven at 100°C for 4 hours, manually grind it for 30 minutes, and add it to 17.8 g·L -1Disperse it in the NiSO4 solution by ultrasonic vibration for 10 min, then stir it in a magnetic stirrer at a stirring rate of 200 r / min for 1 h, filter the obtained solution, and then dry it in an electrothermal constant temperature forced air drying oven at 100 °C for 3 h;

[0044] Manually grind the above-mentioned red mud for 30 minutes, and add it to the mixed solution of 2 g·L -1 of NaBH4, 30 g·L -1 of NaOH, and 50 g·L -1 of C6H5Na3O7 that has been heated to 50 °C in a constant temperature water bath, stir it at a stirring rate of 200 r / min for 10 min, filter it, wash the obtained red mud with deionized water, and dry it in an electrothermal constant temperature forced air drying oven at 100 °C for 8 h.

[0045] S2: Cut the massive industrial pure aluminum, aluminum-copper alloy, aluminum-magnesium alloy, aluminum-silicon alloy, and aluminum-nickel alloy into small pieces in a machine tool, and then place them in an electrothermal constant temperature forced air drying oven at 200 °C for 0.5 h for standby.

[0046] S3: Place 585 g of industrial pure aluminum in a graphite crucible and put it into an intermediate frequency induction heating furnace to heat up to 720 °C with the furnace. After waiting for 20 min for the aluminum block to completely melt, skim off the surface oxide layer, and then measure the temperature with a thermocouple thermometer; adjust the power of the intermediate frequency induction heating furnace until the temperature reaches 730 °C, and then sequentially add 240 g of aluminum-silicon 50 master alloy, 20 g of aluminum-copper 50 master alloy, and 100 g of aluminum-nickel 10 master alloy. After standing and holding for 10 min, stir and skim the slag.

[0047] S4: Adjust the power of the intermediate frequency induction heating furnace. When the furnace temperature drops to 690 °C, quickly press 50 g of aluminum-magnesium 20 master alloy into the bottom of the melt to ensure that it is not oxidized. After holding for 5 minutes, add 10 g of hexachloroethane as a refining agent, and skim the slag again after all the raw materials have melted.

[0048] S5: At 710 °C, mechanically stir for 5 min. During this process, add 5 g of Ni-coated red mud prepared in S1, adjust the power of the intermediate frequency induction heating furnace, and skim the slag at 720 °C to obtain a 0.5 wt.% ZL109 / red mud alloy melt.

[0049] S6: Keep the temperature, pour the above alloy melt into a mold that has been pre-coated with a sodium silicate-zinc oxide mixed coating with a mass ratio of 1:3 and fully preheated at 200 °C, and demold to obtain an alloy ingot.

[0050] S7: Put the ingot into a muffle furnace and heat it up with the furnace to 515 °C and hold for 8 h, then quench it in water at 90 °C to complete solid solution. Then put the water-quenched sample into the muffle furnace and heat it up with the furnace to 175 °C and hold for 12 h, and then cool it with the furnace to room temperature to complete the T6 treatment.

[0051] As shown in the attached Figure 1 figure, when the addition amount of red mud is 0.5%, the peak intensities of the strengthening phases of the T6-state ZL109 / red mud composite heat-resistant aluminum alloy prepared in this example are all increased to some extent, which proves that the addition of red mud improves the content of strengthening phases in the alloy to a certain extent, resulting in different degrees of improvement in the Vickers hardness, room-temperature tensile strength, and high-temperature tensile strength of the alloy. As shown in the attached Figure 2 and 3 figure 4, when the addition amount of red mud is 0.5%, the Vickers hardness of the T6-state ZL109 / red mud composite heat-resistant aluminum alloy prepared in this example is 202.54 HV, and the Vickers hardness of the T6-state ZL109 aluminum alloy without adding red mud is 175.97 HV; the room-temperature tensile strength of the T6-state ZL109 / red mud composite heat-resistant aluminum alloy with 0.5% red mud added is 275.2 MPa, and the room-temperature tensile strength of the T6-state ZL109 aluminum alloy without adding red mud is 265.8 MPa; the tensile strength of the T6-state ZL109 / red mud composite heat-resistant aluminum alloy with 0.5% red mud added at 350 °C is 135.7 MPa, and the tensile strength of the T6-state ZL109 aluminum alloy without adding red mud at 350 °C is 94.6 MPa.

[0052] Example 2

[0053] This example provides a preparation method of a 1 wt.% ZL109 / red mud alloy material, which includes the following steps:

[0054] S1: Place the red mud after removing Fe3O4 by magnetic separation in an electrothermal constant-temperature forced-air drying oven at 100 °C for 4 h, manually grind it for 30 minutes, add it to a NiSO4 solution with a concentration of 17.8 g·L -1 , vibrate it ultrasonically for 10 min to disperse it, then stir it at a stirring rate of 200 r / min in a magnetic stirrer for 1 h, filter the obtained solution, and then place it in an electrothermal constant-temperature forced-air drying oven at 100 °C for 3 h;

[0055] Manually grind the above-obtained red mud for 30 minutes, add it to a mixed solution of 2 g·L -1 NaBH4, 30 g·L -1 NaOH, and 50 g·L -1 C6H5Na3O7 that has been heated to 50 °C in a constant-temperature water bath, and stir it at a stirring rate of 200 r / min for 10 min, filter it, wash the obtained red mud with deionized water, and dry it in an electrothermal constant-temperature forced-air drying oven at 100 °C for 8 h.

[0056] S2: Cut the massive commercial pure aluminum, aluminum-copper alloy, aluminum-magnesium alloy, aluminum-silicon alloy, and aluminum-nickel alloy into small pieces in a machine tool, and then place them in an electrothermal constant-temperature forced-air drying oven at 200 °C for 0.5 h for standby.

[0057] S3: Place 580 g of commercial pure aluminum in a graphite crucible and put it into an intermediate frequency induction heating furnace. Heat it up to 720 °C along with the furnace. After waiting for 20 min until the aluminum blocks are completely melted, skim off the surface oxide layer, and then measure the temperature with a thermocouple thermometer; adjust the power of the intermediate frequency induction heating furnace until the temperature reaches 730 °C, and then successively add 240 g of Al-Si50 master alloy, 20 g of Al-Cu50 master alloy, and 100 g of Al-Ni10 master alloy. After standing and holding for 10 min, stir and skim the slag.

[0058] S4: Adjust the power of the intermediate frequency induction heating furnace. When the furnace temperature drops to 690 °C, quickly press 50 g of Al-Mg20 master alloy to the bottom of the melt to ensure it is not oxidized. After holding for 5 minutes, add 10 g of hexachloroethane as a refining agent. After all the raw materials are melted, skim the slag again.

[0059] S5: At 710 °C, mechanically stir for 5 min. During this process, add 10 g of Ni-coated red mud prepared in S1, adjust the power of the intermediate frequency induction heating furnace, and skim the slag at 720 °C to obtain a 1 wt.% ZL109 / red mud alloy melt.

[0060] S6: Keep the temperature and pour the above alloy melt into a mold that has been pre-coated with a sodium silicate-zinc oxide mixed coating with a mass ratio of 1:3 and fully preheated at 200 °C, and demold to obtain an alloy ingot.

[0061] S7: Put the ingot into a muffle furnace and heat it up to 515 °C along with the furnace and hold for 8 h, then water quench in water at 90 °C to complete solution treatment. Then put the water-quenched sample into the muffle furnace and heat it up to 175 °C along with the furnace and hold for 12 h, and then cool it to room temperature along with the furnace to complete the T6 treatment.

[0062] As shown in the Figure 1 appendix, when the addition amount of red mud is 1%, the peak intensities of the strengthening phases of the T6-state ZL109 / red mud composite heat-resistant aluminum alloy prepared in this example are all increased. Especially the intensity of the Al5Cu2Mg8Si6 phase, which proves that the addition of red mud has increased the content of the strengthening phases in the alloy to a certain extent, resulting in different degrees of improvement in the Vickers hardness, room temperature tensile strength, and high-temperature tensile strength of the alloy. As shown in the Figure 2 、 3As shown in Figure 4, when the addition amount of red mud is 1%, the Vickers hardness of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy prepared in this example is 208.97 HV, and the Vickers hardness of the T6 state ZL109 aluminum alloy without red mud addition is 175.97 HV; the room temperature tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy with 1% red mud addition is 295.4 MPa, and the room temperature tensile strength of the T6 state ZL109 aluminum alloy without red mud addition is 265.8 MPa; the tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy when stretched at 350 °C is 143.3 MPa, and the tensile strength of the T6 state ZL109 aluminum alloy without red mud addition when stretched at 350 °C is 94.6 MPa.

[0063] Example 3

[0064] This example provides a preparation method of a 1.5 wt.% ZL109 / red mud alloy material, including the following steps:

[0065] S1: Place the red mud after removing Fe3O4 by magnetic separation in an electrothermal constant temperature blast drying oven at 100 °C for 4 h, manually grind it for 30 minutes, add it to a NiSO4 solution with a concentration of 17.8 g·L -1 , vibrate it ultrasonically for 10 min to disperse it, then stir it in a magnetic stirrer at a stirring rate of 200 r / min for 1 h, filter the obtained solution, and then place it in an electrothermal constant temperature blast drying oven at 100 °C for 3 h;

[0066] Manually grind the above-obtained red mud for 30 minutes, add it to a mixed solution of 2 g·L -1 NaBH4, 30 g·L -1 NaOH, and 50 g·L -1 C6H5Na3O7 that has been heated to 50 °C in a constant temperature water bath, and stir it at a stirring rate of 200 r / min for 10 min, filter it, wash the obtained red mud with deionized water, and dry it in an electrothermal constant temperature blast drying oven at 100 °C for 8 h.

[0067] S2: Cut the bulk industrial pure aluminum, aluminum-copper alloy, aluminum-magnesium alloy, aluminum-silicon alloy, and aluminum-nickel alloy into small pieces in a machine tool, and then place them in an electrothermal constant temperature blast drying oven at 200 °C for 0.5 h for standby.

[0068] S3: Place 575 g of industrial pure aluminum in a graphite crucible and put it into an intermediate frequency induction heating furnace. Heat it up to 720 °C along with the furnace. After waiting for 20 minutes until the aluminum block is completely melted, skim off the surface oxide layer, and then measure the temperature with a thermocouple thermometer. Adjust the power of the intermediate frequency induction heating furnace until the temperature reaches 730 °C. Then, add 240 g of Al-Si 50 master alloy, 20 g of Al-Cu 50 master alloy, and 100 g of Al-Ni 10 master alloy in sequence. After standing and holding for 10 minutes, stir and skim the slag.

[0069] S4: Adjust the power of the intermediate frequency induction heating furnace. When the furnace temperature drops to 690 °C, quickly press 50 g of Al-Mg 20 master alloy to the bottom of the melt to ensure it is not oxidized. After holding for 5 minutes, add 10 g of hexachloroethane as a refining agent. After all the raw materials are melted, skim the slag again.

[0070] S5: At 710 °C, mechanically stir for 5 minutes. During this process, add 15 g of Ni-coated red mud prepared in S1. Adjust the power of the intermediate frequency induction heating furnace. Skim the slag at 720 °C to obtain a 1 wt.% ZL109 / red mud alloy melt.

[0071] S6: Keep the temperature and pour the above alloy melt into a mold that has been pre-coated with a sodium silicate-zinc oxide mixed coating with a mass ratio of 1:3 and fully preheated at 200 °C. Demold to obtain an alloy ingot.

[0072] S7: Place the ingot in a muffle furnace and heat it up to 515 °C along with the furnace and hold for 8 h. Then, quench it in water at 90 °C to complete solution treatment. Then, put the water-quenched sample into the muffle furnace and heat it up to 175 °C along with the furnace and hold for 12 h. Then, cool it down to room temperature along with the furnace to complete the T6 treatment.

[0073] As shown in the Figure 1 appendix, when the addition amount of red mud is 1.5%, the peak intensities of the strengthening phases of the T6-state ZL109 / red mud composite heat-resistant aluminum alloy prepared in this example are all increased. Especially the intensity of the Al5Cu2Mg8Si6 phase, which proves that the addition of red mud improves the content of the strengthening phases in the alloy to a certain extent, resulting in different degrees of improvement in the Vickers hardness, room temperature tensile strength, and high-temperature tensile strength of the alloy. As shown in the Figure 2 、 3As shown in Figure 4, when the addition amount of red mud is 1.5%, the Vickers hardness of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy prepared in this example is 210.51 HV, and the Vickers hardness of the T6 state ZL109 aluminum alloy without adding red mud is 175.97 HV; the room-temperature tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy with 1.5% red mud added is 231.7 MPa, and the room-temperature tensile strength of the T6 state ZL109 aluminum alloy without adding red mud is 265.8 MPa; the tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy when stretched at 350 °C with 1.5% red mud added is 97.8 MPa, and the tensile strength of the T6 state ZL109 aluminum alloy without adding red mud when stretched at 350 °C is 94.6 Mpa; the tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy when stretched at 400 °C with 1.5% red mud added is 86.2 MPa.

[0074] Example 4

[0075] This example provides a preparation method for a 2 wt.% ZL109 / red mud alloy material, including the following steps:

[0076] S1: Place the red mud after removing Fe3O4 by magnetic separation in an electrothermal constant-temperature forced-air drying oven at 100 °C for 4 h, manually grind it for 30 minutes, add it to a NiSO4 solution with a concentration of 17.8 g·L -1 and vibrate it ultrasonically for 10 min to disperse it, then stir it in a magnetic stirrer at a stirring rate of 200 r / min for 1 h, filter the obtained solution, and then place it in an electrothermal constant-temperature forced-air drying oven at 100 °C for 3 h;

[0077] Manually grind the above-obtained red mud for 30 minutes, add it to a mixed solution of 2 g·L -1 of NaBH4, 30 g·L -1 of NaOH, and 50 g·L -1 of C6H5Na3O7 that has been heated to 50 °C in a constant-temperature water bath, and stir it at a stirring rate of 200 r / min for 10 min, filter it, wash the obtained red mud with deionized water, and dry it in an electrothermal constant-temperature forced-air drying oven at 100 °C for 8 h.

[0078] S2: Cut the massive industrial pure aluminum, aluminum-copper alloy, aluminum-magnesium alloy, aluminum-silicon alloy, and aluminum-nickel alloy into small pieces in a machine tool, and then place them in an electrothermal constant-temperature forced-air drying oven at 200 °C for 0.5 h for standby.

[0079] S3: Place 570 g of industrial pure aluminum in a graphite crucible and put it into an intermediate frequency induction heating furnace. Heat it up to 720 °C along with the furnace. After waiting for 20 min until the aluminum block is completely melted, skim off the surface oxide layer, and then measure the temperature with a thermocouple thermometer. Adjust the power of the intermediate frequency induction heating furnace until the temperature reaches 730 °C. Then, add 240 g of Al - Si50 master alloy, 20 g of Al - Cu50 master alloy, and 100 g of Al - Ni10 master alloy in sequence. After standing and holding for 10 min, stir and skim the slag.

[0080] S4: Adjust the power of the intermediate frequency induction heating furnace. When the furnace temperature drops to 690 °C, quickly press 50 g of Al - Mg20 master alloy to the bottom of the melt to ensure it is not oxidized. After holding for 5 minutes, add 10 g of hexachloroethane as a refining agent. After all the raw materials are melted, skim the slag again.

[0081] S5: At 710 °C, mechanically stir for 5 min. During this process, add 20 g of Ni - coated red mud prepared in S1. Adjust the power of the intermediate frequency induction heating furnace. Skim the slag at 720 °C to obtain a 1 wt.% ZL109 / red mud alloy melt.

[0082] S6: Keep the temperature and pour the above - mentioned alloy melt into a mold that has been pre - coated with a sodium silicate - zinc oxide mixed coating with a mass ratio of 1:3 and fully pre - heated at 200 °C. Demold to obtain an alloy ingot.

[0083] S7: Put the ingot into a muffle furnace and heat it up to 515 °C along with the furnace and hold for 8 h. Then, quench it in water at 90 °C to complete solution treatment. Then, put the water - quenched sample into the muffle furnace and heat it up to 175 °C along with the furnace and hold for 12 h. Then, cool it down to room temperature along with the furnace to complete the T6 treatment.

[0084] As shown in the Figure 1 appendix, when the addition amount of red mud is 2, the peak intensities of the strengthening phases of the T6 - state ZL109 / red mud composite heat - resistant aluminum alloy prepared in this example are all increased. Especially the intensity of the Al5Cu2Mg8Si6 phase, which proves that the addition of red mud improves the content of strengthening phases in the alloy to a certain extent, resulting in different degrees of improvement in the Vickers hardness, room - temperature tensile strength, and high - temperature tensile strength of the alloy. As shown in the Figure 2 、 3As shown in Figure 4, when the addition amount of red mud is 2% (the total mass of the ingot is 1 kg and the amount of red mud is 20 g), the Vickers hardness of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy prepared in this example is 193.81 HV, and the Vickers hardness of the T6 state ZL109 aluminum alloy without red mud addition is 175.97 HV; the room temperature tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy with 2% red mud addition is 216.5 MPa, and the room temperature tensile strength of the T6 state ZL109 aluminum alloy without red mud addition is 265.8 MPa; the tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy with 2% red mud addition at 350 °C is 95.4 MPa, and the tensile strength of the T6 state ZL109 aluminum alloy without red mud addition at 350 °C is 94.6 MPa; the tensile strength of the T6 state ZL109 / red mud composite heat-resistant aluminum alloy with 1.5% red mud addition at 400 °C is 86.2 MPa.

[0085] From the comparison of the test results of the ZL109 / red mud alloy materials with different mass fractions prepared in the above two examples, it can be seen that the addition of red mud coated with Ni improves the Vickers hardness, room temperature tensile strength, and high temperature tensile strength of the matrix alloy material in the T6 state.

[0086] The Vickers hardness increases from 175.97 HV to 210.51 HV, an increase of 19.63%; the room temperature tensile strength increases from 265.8 MPa to 295.4 MPa, an increase of 11.1%; the high temperature tensile strength at 350 °C increases from 94.6 MPa to 143.4 MPa, an increase of 51.5%; the high temperature tensile strength at 400 °C can reach 86.2 MPa. The high temperature tensile strength of this material is higher than that of the aluminum-silicon alloy during the same period at 350 °C, and it is particularly prominent at 400 °C.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a heat-resistant aluminum-silicon alloy material, characterized in that: The heat-resistant aluminum-silicon alloy material includes an Al-12Si-1Cu-1Ni-1Mg matrix alloy and red mud chemically coated with Ni; in terms of mass percentage, the red mud chemically coated with Ni is 0.5wt.%~2wt.%, and the Al-12Si-1Cu-1Ni-1Mg alloy is 98wt.%~99.5wt.%; The preparation method specifically comprises the following steps: S1: chemically coating red mud with Ni after magnetic separation to remove ferroferric oxide; S1-1: Dry the red mud after magnetic separation to remove ferroferric oxide, grind it, add it into NiSO4 solution and disperse it by ultrasonic, stir, filter and dry it; S1-2: Grind the red mud obtained in S1-1, then add it to a mixed solution of NaBH4, NaOH and C6H5Na3O7 at 50°C, stir and filter, wash with deionized water, and dry to obtain Ni-coated red mud; S2: Cutting the blocky aluminum-silicon alloy, aluminum-copper alloy, aluminum-nickel alloy, and aluminum-magnesium alloy into small pieces in a machine tool, and then drying them for standby use; S3: Put industrial pure aluminum into a graphite crucible, place it in an electromagnetic induction furnace to heat and melt, add aluminum silicon alloy, aluminum copper alloy, and aluminum nickel alloy into the melt, let it stand and keep warm, then stir and skim off the slag; S4: After adjusting the temperature, the aluminum-magnesium alloy is pressed into the bottom of the melt obtained in S3, and a refining agent is added after heat preservation, and the slag is skimmed after all the raw materials are melted; S5: adding the Ni-coated red mud obtained in S1 with stirring, adjusting the temperature and skimming off the slag to obtain an Al-12Si-1Cu-1Ni-1Mg / red mud alloy material melt; S6: injecting the Al-12Si-1Cu-1Ni-1Mg / red mud alloy material melt into a mold, and demolding to obtain an ingot of the Al-12Si-1Cu-1Ni-1Mg / red mud alloy material; S7: The alloy material prepared in S6 is subjected to T6 heat treatment to obtain the target product.

2. The method for preparing a heat-resistant aluminum-silicon alloy material according to claim 1, characterized in that: In S1-1, the concentration of NiSO4 solution is 17.8 g·L -1 ; Ultrasonic time is 10min; Stirring rate is 200r / min, stirring time is 1h; In S1-2, the concentration of NaBH4 is 2 g·L -1 , the concentration of NaOH is 30 g·L -1 , the concentration of C6H5Na3O7 is 50g·L -1 , the stirring rate is 200r / min, and the stirring time is 10min.

3. The method for preparing a heat-resistant aluminum-silicon alloy material according to claim 1, characterized in that: In S2, the drying condition is: drying in an electric constant temperature blast drying oven at 200°C for 0.5h, wherein the heating rate of the drying oven is 5-10°C / min.

4. The method for preparing a heat-resistant aluminum-silicon alloy material according to claim 1, characterized in that: In S3, the temperature of the electromagnetic induction furnace is 720° C.; the static holding time is 10 min; and the mass ratio of the aluminum-silicon alloy, the aluminum-copper alloy, and the aluminum-nickel alloy is 12:1:

1.

5. The method for preparing a heat-resistant aluminum-silicon alloy material according to claim 1, characterized in that: In S4, the temperature is adjusted to 680-700° C. and kept warm for 5 minutes; the refining agent is hexachloroethane.

6. The method for preparing a heat-resistant aluminum-silicon alloy material according to claim 1, characterized in that: In S5, the stirring temperature is 710°C, the stirring speed is 600r / min, and the stirring time is 5min; the temperature is adjusted to 720-730°C for slagging.

7. The method for preparing a heat-resistant aluminum-silicon alloy material according to claim 1, characterized in that: In S6, after the mold is coated with a sodium silicate / zinc oxide mixed coating in a mass ratio of 1:3, it is placed in a muffle furnace and preheated to 200°C.

8. The method for preparing a heat-resistant aluminum-silicon alloy material according to claim 1, characterized in that: The specific operation of S7 is: placing the ingot in a muffle furnace and heating it to 515°C and keeping it warm for 8 hours, then quenching it in water at 90-100°C to complete the solid solution, then placing the sample in a muffle furnace and heating it to 175°C and keeping it warm for 12 hours, and then cooling it to room temperature to complete the T6 heat treatment.

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