Aluminum alloy for resistor as well as production process and application of aluminum alloy

Abstract

The invention belongs to the field of aluminum alloys, and particularly relates to an aluminum alloy for a resistor and a production process and application of the aluminum alloy for the resistor. Fe: less than or equal to 0.1%; less than 0.05% of Cu; less than 0.02% of V + Ti; and the balance of Al and inevitable impurity elements. By reasonably optimizing the raw material ratio of the aluminum alloy formula and finely controlling the temperature condition and the time condition in the cold rolling step and the annealing step, the components and the tissue are more uniform, the internal tissue structure is improved, the mechanical property is improved, and the rolling mechanical property meets the requirements that the tensile strength is larger than 170 MPa, the ductility is larger than or equal to 15.0%, and the elongation percentage is larger than or equal to 15.0%. And the mechanical requirements of aluminum alloy raw materials for resistors are met. In addition, five times of cold and hot alternate quenching are adopted, air holes and defects are further reduced, the porosity in the die casting can be reduced to 3.1% from original 8.8%, the hardness is improved to 131 HB from original 93 HB, and the machining and follow-up application requirements of the aluminum alloy raw material for the resistor are met.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloys, and in particular relates to an aluminum alloy for resistors and a production process and application thereof. Background Art

[0002] Aluminum alloy resistor material is a lightweight metal material with excellent electrical conductivity and mechanical properties, suitable for manufacturing various electronic components and resistors. In the production process, high-quality, standard aluminum alloy raw materials must be selected first. These raw materials should undergo rigorous chemical composition analysis and mechanical property testing to ensure the quality and performance of the final product.

[0003] At present, the aluminum alloys used to produce resistor materials on the market have defects such as poor mechanical properties and poor electrical conductivity, which makes it difficult to meet the strict requirements of the resistor material production industry for raw materials. Summary of the invention

[0004] The object of the present invention is to provide an aluminum alloy for resistor and its production process and application to solve the above-mentioned problems.

[0005] In a first aspect, an aluminum alloy for resistors comprises the following components in percentage by mass:

[0006] Si: ≤0.07%; Fe: ≤0.1%; Cu: <0.05%; V+Ti <0.02%; the balance is Al and unavoidable impurity elements.

[0007] As a further improvement, the tensile strength of the aluminum alloy for resistors is greater than 170 MPa, and the elongation of the aluminum alloy for resistors is greater than or equal to 15.0%.

[0008] In a second aspect, a production process of an aluminum alloy for resistors comprises the following steps:

[0009] Step 1, smelting and refining:

[0010] Weigh raw materials according to the formula, add the raw materials into a smelting furnace for smelting, refining, and standing to obtain aluminum alloy melt, and cast the aluminum alloy melt to obtain a plate ingot;

[0011] Step 2: Hot rolling:

[0012] Hot rolling the plate ingot to obtain a hot-rolled coil blank;

[0013] Step 3, cold rolling and annealing:

[0014] The hot-rolled coil blank is subjected to cold rolling, intermediate annealing, cold rolling and final annealing to obtain the aluminum alloy for resistor.

[0015] As a further improvement, in step 1, the refining temperature is 720-750°C, the refining time is 15-35 minutes, and the refining is allowed to stand for 10-60 minutes.

[0016] As a further improvement, in step 1, the casting is performed by a vacuum die-casting machine, the vacuum degree is less than 50 mbar, and the pouring temperature is 650°C to 700°C.

[0017] As a further improvement, in step 1, five times of alternating hot and cold quenching are also used during the vacuum die casting process.

[0018] As a further improvement, in step 1, a cooling channel is provided inside the die-casting mold used in the vacuum die-casting machine, and an electromagnetic induction heater is also provided outside the die-casting mold for electromagnetic induction heating the die-casting mold and the casting inside the die-casting mold;

[0019] After the aluminum alloy melt is injected into the die-casting mold, the injection pressure is 72MPa. Liquid nitrogen is first input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 7±2s, the liquid nitrogen and gas in the cooling channel are immediately drained. After that, the die-casting mold is heated by an electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa.

[0020] The electromagnetic induction heater stops heating, and liquid carbon dioxide is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 13±2s, the liquid carbon dioxide and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 740°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0021] The electromagnetic induction heater stops heating, and 0℃ ice water is input into the cooling channel to cool the die-casting mold. After the temperature is kept for 60±5s, the ice water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 730℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0022] The electromagnetic induction heater stops heating, and 25°C cooling water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 5±0.5 minutes, the cooling water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 720°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0023] The electromagnetic induction heater stops heating, and 25-30℃ air is input into the cooling channel to cool the die-casting mold. After the temperature is maintained for 10±0.5min, the input of 25-30℃ air is stopped and the mold is naturally cooled to room temperature.

[0024] As a further improvement, in step 2, the final rolling temperature of hot rolling is controlled to be 340±5°C.

[0025] Further improvement, in step 3, the initial furnace gas temperature of the intermediate annealing is 420°C, when the material temperature rises to 300°C, the furnace gas temperature drops to 390°C, and the final material temperature is kept at 310-380°C for 2-6 hours;

[0026] and / or,

[0027] In step 3, the initial furnace gas temperature for annealing the finished product is 380°C. When the material temperature rises to 250°C, the furnace gas temperature drops to 270°C. The final material temperature is kept at 250-330°C for 2-7 hours.

[0028] A third aspect is the use of the aluminum alloy for resistors in the preparation of resistor materials.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention reasonably optimizes the raw material ratio of the aluminum alloy formula, and finely controls the temperature conditions and time conditions in the cold rolling step and the annealing step, so as to make the composition and organization more uniform, improve the internal organizational structure, and improve the mechanical properties. The rolling mechanical properties meet the following requirements: tensile strength>170MPa, elongation≥15.0%, which meet the mechanical requirements of aluminum alloy raw materials for resistors.

[0031] 2. The present invention further optimizes the existing vacuum die-casting process. By adopting five times of alternating hot and cold quenching, the pores and defects are further reduced, the porosity in the die-casting can be reduced from the original 8.8% to 3.1%, and the hardness is increased from the original 93HB to 131HB, which meets the processing and subsequent application requirements of aluminum alloy raw materials for resistors.

[0032] 3. Effectively improve the surface quality of the product, and the surface smoothness and color consistency of the product after rolling are good. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below through specific examples.

[0034] Example 1

[0035] Formula 1: comprising the following components in percentage by weight:

[0036] Si: ≤0.07%; Fe: ≤0.1%; Cu: <0.05%; V+Ti <0.02%; the balance is Al and unavoidable impurity elements.

[0037] 3. The production process of the aluminum alloy for resistor according to claim 1, characterized in that it comprises the following steps:

[0038] Step 1, smelting and refining:

[0039] The raw materials are weighed according to the formula, added into a smelting furnace for smelting, refining, and standing to obtain an aluminum alloy melt, and the aluminum alloy melt is cast to obtain a plate ingot; wherein, the refining temperature is 720-750°C, the refining time is 15-35min, and after the refining is completed, it is stood for 10-60min.

[0040] The casting is carried out by vacuum die casting machine, the vacuum degree is less than 50mbar, and the pouring temperature is 650℃~700℃.

[0041] Step 2: Hot rolling:

[0042] The plate ingot is hot rolled, and the final rolling temperature of the hot rolling is controlled to be 340±5° C. to obtain a hot-rolled coil blank.

[0043] Step 3, cold rolling and annealing:

[0044] The hot rolled coil blank is subjected to cold rolling, intermediate annealing, cold rolling and finished annealing to obtain the aluminum alloy for resistor. The initial furnace gas temperature of the intermediate annealing is 420°C, when the material temperature rises to 300°C, the furnace gas temperature drops to 390°C, and the final material temperature is kept at 310-380°C for 2-6 hours;

[0045] The initial furnace gas temperature for finished product annealing is 380°C. When the material temperature rises to 250°C, the furnace gas temperature drops to 270°C. The final material temperature is kept at 250-330°C for 2-7 hours.

[0046] The tensile strength of the aluminum alloy for resistors is 173 MPa, the elongation of the aluminum alloy for resistors is 15.7%, the porosity of the plate ingot is 8.8%, and the hardness of the plate ingot is 93 HB.

[0047] Example 2

[0048] The difference between this example and Example 1 is that in step 1, five cold and hot alternating quenchings are also used during the vacuum die casting process, specifically:

[0049] The die-casting mold used in the vacuum die-casting machine is provided with a cooling channel inside, and an electromagnetic induction heater is also provided outside the die-casting mold for electromagnetic induction heating of the die-casting mold and the casting inside it;

[0050] After the aluminum alloy melt is injected into the die-casting mold, the injection pressure is 72MPa. Liquid nitrogen is first input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 7±2s, the liquid nitrogen and gas in the cooling channel are immediately drained. After that, the die-casting mold is heated by an electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa.

[0051] The electromagnetic induction heater stops heating, and liquid carbon dioxide is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 13±2s, the liquid carbon dioxide and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 740°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0052] The electromagnetic induction heater stops heating, and 0℃ ice water is input into the cooling channel to cool the die-casting mold. After the temperature is kept for 60±5s, the ice water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 730℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0053] The electromagnetic induction heater stops heating, and 25°C cooling water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 5±0.5 minutes, the cooling water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 720°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0054] The electromagnetic induction heater stops heating, and 25-30℃ air is input into the cooling channel to cool the die-casting mold. After the temperature is maintained for 10±0.5min, the input of 25-30℃ air is stopped and the mold is naturally cooled to room temperature.

[0055] The tensile strength of the aluminum alloy for resistors is 198 MPa (14% higher than that of Example 1), the elongation of the aluminum alloy for resistors is 13.3%, the porosity of the plate ingot is 3.1% (65% lower than that of Example 1), and the hardness of the plate ingot is 131 HB (41% higher than that of Example 1).

[0056] Comparative Example 1

[0057] The difference between this example and Example 2 is that, during the vacuum die-casting process, only one hot and cold alternating quenching is used, specifically:

[0058] After the aluminum alloy melt is injected into the die casting mold, the injection pressure is 72MPa. Liquid nitrogen is first input into the cooling channel to cool the die casting mold. After the cooling is maintained for 7±2s, the liquid nitrogen and gas in the cooling channel are immediately drained; then, the die casting mold is heated by an electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die casting mold, and the injection pressure is maintained at 50-72MPa; then, it is naturally cooled to room temperature; the rest are the same. The final plate ingot has a porosity of 10.3% and a hardness of 95HB.

[0059] Comparative Example 2

[0060] The difference between this example and Example 2 is that, during the vacuum die-casting process, only one hot and cold alternating quenching is used, specifically:

[0061] Liquid carbon dioxide is input into the cooling channel to cool the die casting mold. After the cooling is maintained for 13±2s, the liquid carbon dioxide and gas in the cooling channel are immediately drained; then, the die casting mold is heated by an electromagnetic induction heater to 740℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die casting mold, and the injection pressure is maintained at 50-72MPa; then, it is naturally cooled to room temperature; the rest are the same. The final plate ingot has a porosity of 9.7% and a hardness of 89HB.

[0062] Comparative Example 3

[0063] The difference between this example and Example 2 is that, during the vacuum die-casting process, only one hot and cold alternating quenching is used, specifically:

[0064] The die casting mold is cooled by inputting 0℃ ice water into the cooling channel. After the cooling is maintained for 60±5s, the ice water and gas in the cooling channel are immediately drained; then, the die casting mold is heated by an electromagnetic induction heater to 730℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die casting mold, and the injection pressure is maintained at 50-72MPa; then, it is naturally cooled to room temperature; the rest are the same. The final plate ingot has a porosity of 8.2% and a hardness of 96HB.

[0065] Comparative Example 4

[0066] The difference between this example and Example 2 is that, during the vacuum die-casting process, only one hot and cold alternating quenching is used, specifically:

[0067] The die casting mold is cooled by inputting cooling water at 25℃ into the cooling channel. After the cooling is maintained for 5±0.5min, the cooling water and gas in the cooling channel are immediately drained; then, the die casting mold is heated by an electromagnetic induction heater to 720℃ and kept warm for 5min. At this time, semi-solid molten metal is formed in the die casting mold, and the injection pressure is maintained at 50-72MPa; then, it is naturally cooled to room temperature; the rest are the same. The final plate ingot has a porosity of 8.0% and a hardness of 94HB.

[0068] Comparative Example 5

[0069] The difference between this example and Example 2 is that during the five cold and hot alternating quenching processes, the reheating temperature is 750°C, specifically:

[0070] After the aluminum alloy melt is injected into the die-casting mold, the injection pressure is 72MPa. Liquid nitrogen is first input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 7±2s, the liquid nitrogen and gas in the cooling channel are immediately drained. After that, the die-casting mold is heated by an electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa.

[0071] The electromagnetic induction heater stops heating, and liquid carbon dioxide is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 13±2s, the liquid carbon dioxide and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0072] The electromagnetic induction heater stops heating, and 0℃ ice water is input into the cooling channel to cool the die-casting mold. After the temperature is kept for 60±5s, the ice water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0073] The electromagnetic induction heater stops heating, and 25°C cooling water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 5±0.5 minutes, the cooling water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 750°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0074] The electromagnetic induction heater stops heating, and 25-30℃ air is input into the cooling channel to cool the die-casting mold. After the temperature is maintained for 10±0.5min, the input of 25-30℃ air is stopped and the mold is naturally cooled to room temperature.

[0075] The porosity of the final plate ingot is 4.0%, and the hardness of the plate ingot is 105 HB.

[0076] Comparative Example 6

[0077] The difference between this example and Example 2 is that during the five cold and hot alternating quenching processes, the reheating temperature is 720°C, specifically:

[0078] After the aluminum alloy melt is injected into the die-casting mold, the injection pressure is 72MPa. Liquid nitrogen is first input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 7±2s, the liquid nitrogen and gas in the cooling channel are immediately drained. After that, the die-casting mold is heated by an electromagnetic induction heater to 720℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa.

[0079] The electromagnetic induction heater stops heating, and liquid carbon dioxide is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 13±2s, the liquid carbon dioxide and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 720℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0080] The electromagnetic induction heater stops heating, and 0℃ ice water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 60±5s, the ice water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 720℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0081] The electromagnetic induction heater stops heating, and 25°C cooling water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 5±0.5 minutes, the cooling water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 720°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0082] The electromagnetic induction heater stops heating, and 25-30℃ air is input into the cooling channel to cool the die-casting mold. After the temperature is maintained for 10±0.5min, the input of 25-30℃ air is stopped and the mold is naturally cooled to room temperature.

[0083] The porosity of the final plate ingot is 3.8% and the hardness of the plate ingot is 99 HB.

[0084] Comparative Example 7

[0085] The only difference between this example and Example 2 is that during the five cold and hot alternating quenching processes, the cooling holding time is 10±0.5min, specifically:

[0086] After the aluminum alloy melt is injected into the die-casting mold, the injection pressure is 72MPa. Liquid nitrogen is first input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 10±0.5min, the liquid nitrogen and gas in the cooling channel are immediately drained. After that, the die-casting mold is heated by an electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa.

[0087] The electromagnetic induction heater stops heating, and liquid carbon dioxide is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 10±0.5 minutes, the liquid carbon dioxide and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 740°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0088] The electromagnetic induction heater stops heating, and 0℃ ice water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 10±0.5min, the ice water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 730℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0089] The electromagnetic induction heater stops heating, and 25°C cooling water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 10±0.5 minutes, the cooling water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 720°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa;

[0090] The electromagnetic induction heater stops heating, and 25-30℃ air is input into the cooling channel to cool the die-casting mold. After the temperature is maintained for 10±0.5min, the input of 25-30℃ air is stopped and the mold is naturally cooled to room temperature.

[0091] The hardness of the final plate ingot is 88HB.

[0092] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An aluminum alloy for resistor, characterized in that: The following components are included in mass percentage: Si: ≤0.07%; Fe: ≤0.1%; Cu: <0.05%; V+Ti <0.02%; the balance is Al and unavoidable impurity elements.

2. The aluminum alloy for resistor according to claim 1, characterized in that: The tensile strength of the aluminum alloy for resistors is greater than 170 MPa, and the elongation of the aluminum alloy for resistors is greater than or equal to 15.0%.

3. The production process of the aluminum alloy for resistor according to claim 1, characterized in that: The following steps are involved: Step 1, smelting and refining: Weigh raw materials according to the formula, add the raw materials into a smelting furnace for smelting, refining, and standing to obtain aluminum alloy melt, and cast the aluminum alloy melt to obtain a plate ingot; Step 2: Hot rolling: Hot rolling the plate ingot to obtain a hot-rolled coil blank; Step 3, cold rolling and annealing: The hot-rolled coil blank is subjected to cold rolling, intermediate annealing, cold rolling and final annealing to obtain the aluminum alloy for resistor.

4. The production process of the aluminum alloy for resistor according to claim 1, characterized in that: In step 1, the refining temperature is 720-750°C, the refining time is 15-35 minutes, and the refining is completed and left to stand for 10-60 minutes.

5. The production process of the aluminum alloy for resistor according to claim 1, characterized in that: In step 1, vacuum die casting is performed using a vacuum die casting machine, the vacuum degree is less than 50 mbar, and the pouring temperature is 650° C. to 700° C.

6. The production process of the aluminum alloy for resistor according to claim 5, characterized in that: In step 1, five hot and cold alternating quenchings are also used during the vacuum die casting process.

7. The production process of the aluminum alloy for resistor according to claim 6, characterized in that: In step 1, a cooling channel is provided inside the die-casting mold used in the vacuum die-casting machine, and an electromagnetic induction heater is also provided outside the die-casting mold for electromagnetic induction heating of the die-casting mold and the casting inside the die-casting mold; After the aluminum alloy melt is injected into the die-casting mold, the injection pressure is 72MPa. Liquid nitrogen is first input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 7±2s, the liquid nitrogen and gas in the cooling channel are immediately drained. After that, the die-casting mold is heated by an electromagnetic induction heater to 750℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa. The electromagnetic induction heater stops heating, and liquid carbon dioxide is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 13±2s, the liquid carbon dioxide and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 740°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa; The electromagnetic induction heater stops heating, and 0℃ ice water is input into the cooling channel to cool the die-casting mold. After the temperature is kept for 60±5s, the ice water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 730℃ and kept warm for 5min. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa; The electromagnetic induction heater stops heating, and 25°C cooling water is input into the cooling channel to cool the die-casting mold. After the cooling is maintained for 5±0.5 minutes, the cooling water and gas in the cooling channel are immediately drained; then, the die-casting mold is heated by the electromagnetic induction heater to 720°C and kept warm for 5 minutes. At this time, semi-solid metal liquid is formed in the die-casting mold, and the injection pressure is maintained at 50-72MPa; The electromagnetic induction heater stops heating, and 25-30℃ air is input into the cooling channel to cool the die-casting mold. After the temperature is maintained for 10±0.5min, the input of 25-30℃ air is stopped and the mold is naturally cooled to room temperature.

8. The production process of the aluminum alloy for resistor according to claim 1, characterized in that: In step 2, the final rolling temperature of hot rolling is controlled to be 340±5°C.

9. The production process of the aluminum alloy for resistor according to claim 1, characterized in that: In step 3, the initial furnace gas temperature of the intermediate annealing is 420°C. When the material temperature rises to 300°C, the furnace gas temperature drops to 390°C. The final material temperature is kept at 310-380°C for 2-6 hours. and / or, In step 3, the initial furnace gas temperature for annealing the finished product is 380°C. When the material temperature rises to 250°C, the furnace gas temperature drops to 270°C. The final material temperature is kept at 250-330°C for 2-7 hours.

10. Use of the aluminum alloy for resistor according to claim 1 or 2 in preparing resistor materials.