Corrosion-resistant aluminum alloy mold and machining process thereof

Abstract

The invention discloses a corrosion-resistant aluminum alloy mold and a machining process thereof, and relates to the technical field of aluminum alloys, and the machining process comprises the following steps: adding aluminum powder, vanadium powder and stearic acid into a ball mill for ball milling in an argon atmosphere, and carrying out cold pressing, polishing and heat treatment on the ball-milled mixed powder to obtain an aluminum alloy mold; ultrasonically washing the surface of the aluminum alloy die with ethanol, and drying with nitrogen for later use; under the argon atmosphere, an electric arc directional energy deposition process is adopted for the surface of the aluminum alloy mold, and an aluminum-based cladding is obtained; the surface of the aluminum alloy mold with the aluminum-based cladding on the surface is polished, subjected to ethanol ultrasonic washing and subjected to nitrogen drying for standby application; hydroxylation treatment is conducted on the aluminum alloy mold with the aluminum-based cladding on the surface, and a pretreated aluminum alloy mold is obtained; and the pretreated aluminum alloy mold is placed in a reaction container to be subjected to pre-passivation treatment, then a plasma electrolytic oxidation process, ultrasonic washing in deionized water and vacuum drying are conducted, a corrosion-resistant protective layer is obtained, and the corrosion-resistant aluminum alloy mold is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloys, in particular to a corrosion-resistant aluminum alloy mold and a processing technology thereof. Background Art

[0002] In the field of industrial manufacturing, aluminum alloy molds are widely used in key fields such as aerospace, automobile manufacturing, and electronic devices due to their light weight, easy processing, and good comprehensive mechanical properties. However, aluminum alloy materials themselves have insufficient corrosion resistance. When used in complex environments such as moisture, acid and alkali, the mold surface is prone to oxidation, pitting or intergranular corrosion, resulting in a decrease in mold dimensional accuracy and an increase in surface roughness, which in turn affects product quality and mold service life.

[0003] In the existing technology, the methods to improve the corrosion resistance of aluminum alloy molds mainly include alloy composition optimization, surface coating treatment and electrochemical protection. However, the traditional alloying method has limited effect on improving corrosion resistance and may sacrifice the processing performance of the material; although the surface coating (such as anodizing, chemical plating, etc.) can isolate the corrosive medium to a certain extent, the bonding force between the coating and the substrate is weak, and it is easy to peel off and crack during long-term service; in addition, there is still a lack of efficient protection solutions for multi-factor coupled corrosion in complex environments (such as the synergistic effect of electrochemical corrosion and mechanical wear). Therefore, the development of an aluminum alloy mold and its preparation process with excellent corrosion resistance, wear resistance and structural stability has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a corrosion-resistant aluminum alloy mold and a processing technology thereof to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: A corrosion-resistant aluminum alloy mold comprises an aluminum alloy mold, an aluminum-based cladding layer arranged on the surface of the aluminum alloy mold and obtained by an arc directional energy deposition process, and a corrosion-resistant protective layer arranged on the surface of the aluminum-based cladding layer.

[0006] A processing technology for a corrosion-resistant aluminum alloy mold comprises the following steps: S1: In an argon atmosphere, aluminum powder, vanadium powder and stearate are added to a ball mill for ball milling, and the milled mixed powder is cold pressed, polished and heat treated to obtain an aluminum alloy mold; S2: After ultrasonically washing the surface of the aluminum alloy mold with ethanol, the surface is dried with nitrogen for later use; in an argon atmosphere, an arc directed energy deposition process is applied to the surface of the aluminum alloy mold to obtain an aluminum-based cladding; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; hydroxylate the surface of the aluminum alloy mold with an aluminum-based cladding to obtain a pretreated aluminum alloy mold; place the pretreated aluminum alloy mold in a reaction vessel for pre-passivation treatment, and then carry out a plasma electrolytic oxidation process, wash it ultrasonically in deionized water, and dry it in vacuum to obtain a corrosion-resistant protective layer and a corrosion-resistant aluminum alloy mold.

[0007] Further, in the preparation process of the aluminum alloy mold, the mass ratio of aluminum powder to vanadium powder is (95 - 97):(3 - 5); the cold pressing pressure is 3 - 5 GPa, and the cold pressing time is 10 - 15 min; the heat treatment temperature is 150 - 200 °C.

[0008] Further, the addition amount of the hard acid ester is 1.5 wt% of the total mass of the aluminum powder and vanadium powder; Further, in the ball milling process, the ball-to-material ratio is 16:1; Further, the purity of the aluminum powder is 99.7%, and the particle size is 50 - 150 mesh; Further, the purity of the vanadium powder is 99.8%, and the particle size is 90 - 100 mesh; Further, in the preparation process of the aluminum-based cladding, the wire parameters used in the arc directed energy deposition process include: the diameter is 1.2 - 1.25 mm, the material is AA2024 aluminum alloy added with TiC nanoparticles, and the mass ratio of TiC nanoparticles to AA2024 aluminum alloy is (2 - 3):(97 - 98).

[0009] Further, in the preparation process of the aluminum-based cladding, the arc directed energy deposition process parameters include: the wire feeding speed is 130 - 135 cm / min, the deposition speed is 10 - 10.1 cm / min, the EP current is 110 A, the EP current is 220 A, the EN - EP balance is 80%, the AC frequency is 100 Hz, the voltage is 12.5 V, and the interlayer temperature is 80 - 82 °C.

[0010] Further, in the preparation process of the pretreated aluminum alloy mold, the hydroxylation treatment step is to immerse the aluminum alloy mold with an aluminum-based cladding on the surface in boiling deionized water for 2 - 3 min, take it out, and anneal it at 170 - 175 °C for 1 - 1.5 h in a nitrogen atmosphere.

[0011] Further, in the preparation process of the corrosion-resistant protective layer, the pre-passivation treatment step is to place the pretreated aluminum alloy mold in a reaction vessel, introduce a hydrogen mixed gas containing 1 - 1.2% HSiCl3, react at room temperature for 1 - 3 h, evacuate, and purge with nitrogen to remove unreacted gases.

[0012] Further, in the preparation process of the corrosion-resistant protective layer, the electrolyte parameters of the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92.

[0013] Further, in the preparation process of the corrosion-resistant protective layer, the plasma electrolytic oxidation process parameters include: a pulse frequency of 980 - 1000 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically, it is processed at 400 V for 5 min, 430 V for 2 min, 460 V for 2 min, 480 V for 2 min, 500 V for 2 min, 520 V for 2 min, 540 V for 2 min, 560 V for 2 min, 580 V for 2 min, and 600 V for 2 min.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention adopts the high-energy ball milling process, where Al powder and V powder are ball milled in an argon atmosphere to form nanocrystals and supersaturated solid solutions; the high solid solubility of V improves the hardness through solid solution strengthening. At the same time, V enriches at the passive film / metal interface, inhibiting local corrosion and promoting repassivation. Cold pressing combined with low-temperature aging heat treatment further refines the grains and inhibits the coarsening of the Al3V precipitation phase. During the aging process, the synergistic effect of the decrease in V solid solubility and the nanoscale precipitation phase optimizes the balance between strength and corrosion resistance.

[0015] 2. The present invention uses an AA2024 welding wire containing TiC nanoparticles for arc-directed energy deposition. TiC serves as a heterogeneous nucleation site, reducing the nucleation undercooling degree and promoting the formation of equiaxed grains. At the same time, TiC particles are pushed to the grain boundaries by the solid-liquid interface, hindering grain growth, reducing porosity and solidification shrinkage defects. TiC nanoparticles, as strengthening phases, inhibit crack propagation through grain refinement strengthening and dispersion strengthening.

[0016] 3. The present invention oxidizes and hydroxylates the polished alloy surface in boiling water to form flaky and needle-like hydroxyoxides AlOOH. HSiCl3 dissociates and mainly forms HSiOH n (OAl) 3-n 、HSi(OSi) n (OAl) 3-n and condensed HSiO x substances, which pave the way for the subsequent formation of a silica ceramic corrosion-resistant protective layer by the plasma electrolytic oxidation process, improving the bonding force between the silica ceramic corrosion-resistant protective layer and the substrate, and enhancing the corrosion resistance and wear resistance. Specific embodiments

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] Embodiment 1: A processing technology for a corrosion-resistant aluminum alloy mold, comprising the following steps: S1: Under an argon atmosphere, aluminum powder, vanadium powder, and 1.5 wt% stearic acid ester are added to a ball mill, and ball milling is performed with a ball-to-material ratio of 16:1. The ball-milled mixed powder is cold-pressed at a pressure of 5 GPa for 10 min, polished with 1200-mesh SiC sandpaper, and heat-treated at 150 °C to obtain an aluminum alloy mold; wherein, the mass ratio of aluminum powder to vanadium powder is 97:3; S2: After ultrasonic washing the surface of the aluminum alloy mold with ethanol, it is dried with nitrogen for standby; under an argon atmosphere, an arc-directed energy deposition process is used on the surface of the aluminum alloy mold to obtain an aluminum-based cladding; wherein, the wire parameters used in the arc-directed energy deposition process include: a diameter of 1.2 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and the mass ratio of TiC nanoparticles to AA2024 aluminum alloy is 2:98; the arc-directed energy deposition process parameters include: a wire feeding speed of 130 cm / min, a deposition speed of 10 cm / min, an EP current of 110 A, an EP current of 220 A, an EN-EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 °C; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; Immerse the aluminum alloy mold with an aluminum-based cladding on its surface in boiling deionized water for 3 minutes, take it out, and anneal it at 170 °C for 1 hour in a nitrogen atmosphere to obtain a pretreated aluminum alloy mold; Place the pretreated aluminum alloy mold in a reaction vessel, introduce a hydrogen mixed gas containing 1% HSiCl3, react at room temperature for 1 hour, evacuate the air, purge with nitrogen to remove unreacted gases, and then carry out the plasma electrolytic oxidation process, wash ultrasonically in deionized water, and dry in vacuum to obtain a corrosion-resistant protective layer and a corrosion-resistant aluminum alloy mold. Among them, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92; The plasma electrolytic oxidation process parameters include: a pulse frequency of 980 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically treating for 5 minutes at 400 V, 2 minutes at 430 V, 2 minutes at 460 V, 2 minutes at 480 V, 2 minutes at 500 V, 2 minutes at 520 V, 2 minutes at 540 V, 2 minutes at 560 V, 2 minutes at 580 V, and 2 minutes at 600 V.

[0019] Example 2: A processing technology for a corrosion-resistant aluminum alloy mold, comprising the following steps: S1: Under an argon atmosphere, add aluminum powder, vanadium powder, and 1.5 wt% stearate to a ball mill, and carry out ball milling with a ball-to-material ratio of 16:1. Cold press the ball-milled mixed powder at a pressure of 5 GPa for 10 minutes, polish it with 1200-mesh SiC sandpaper, and heat-treat it at 150 °C to obtain an aluminum alloy mold; Among them, the mass ratio of aluminum powder to vanadium powder is 95:5; S2: After ultrasonically washing the surface of the aluminum alloy mold with ethanol, dry it with nitrogen for standby; Under an argon atmosphere, use the arc-directed energy deposition process on the surface of the aluminum alloy mold to obtain an aluminum-based cladding; Among them, the wire parameters for the arc-directed energy deposition process include: a diameter of 1.2 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and a mass ratio of TiC nanoparticles to AA2024 aluminum alloy of 2:98; The arc-directed energy deposition process parameters include: a wire feeding speed of 130 cm / min, a deposition speed of 10 cm / min, an EP current of 110 A, an EP current of 220 A, an EN-EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 °C; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; Immerse the aluminum alloy mold with an aluminum-based cladding on its surface in boiling deionized water for 3 minutes, take it out, and anneal it at 170 °C for 1 hour in a nitrogen atmosphere to obtain a pretreated aluminum alloy mold; Place the pretreated aluminum alloy mold in a reaction vessel, introduce a hydrogen mixed gas containing 1% HSiCl3, react at room temperature for 1 hour, evacuate, purge with nitrogen to remove unreacted gases, and then perform a plasma electrolytic oxidation process, wash ultrasonically in deionized water, and dry in vacuum to obtain a corrosion-resistant protective layer, thus obtaining a corrosion-resistant aluminum alloy mold. Among them, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92; The plasma electrolytic oxidation process parameters include: a pulse frequency of 980 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically treating for 5 minutes at 400 V, 2 minutes at 430 V, 2 minutes at 460 V, 2 minutes at 480 V, 2 minutes at 500 V, 2 minutes at 520 V, 2 minutes at 540 V, 2 minutes at 560 V, 2 minutes at 580 V, and 2 minutes at 600 V.

[0020] Example 3: A processing technology for a corrosion-resistant aluminum alloy mold, comprising the following steps: S1: Under an argon atmosphere, add aluminum powder, vanadium powder, and 1.5 wt% stearate to a ball mill, and perform ball milling with a ball-to-material ratio of 16:1. Cold-press the ball-milled mixed powder for 10 minutes under a pressure of 5 GPa, polish it with 1200-mesh SiC sandpaper, and perform heat treatment at 200 °C to obtain an aluminum alloy mold; Among them, the mass ratio of aluminum powder to vanadium powder is 95:5; S2: After ultrasonically washing the surface of the aluminum alloy mold with ethanol, dry it with nitrogen for standby; Under an argon atmosphere, adopt an arc-directed energy deposition process on the surface of the aluminum alloy mold to obtain an aluminum-based cladding; Among them, the wire parameters for the arc-directed energy deposition process include: a diameter of 1.2 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and a mass ratio of TiC nanoparticles to AA2024 aluminum alloy of 2:98; The arc-directed energy deposition process parameters include: a wire feeding speed of 130 cm / min, a deposition speed of 10 cm / min, an EP current of 110 A, an EP current of 220 A, an EN-EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 °C; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; Immerse the aluminum alloy mold with an aluminum-based cladding on its surface in boiling deionized water for 3 minutes, take it out, and anneal it at 170 °C for 1 hour in a nitrogen atmosphere to obtain a pretreated aluminum alloy mold; Place the pretreated aluminum alloy mold in a reaction vessel, introduce a hydrogen mixed gas containing 1% HSiCl3, react at room temperature for 1 hour, evacuate the vacuum, purge with nitrogen to remove unreacted gases, and then perform a plasma electrolytic oxidation process, wash it ultrasonically in deionized water, and dry it in vacuum to obtain a corrosion-resistant protective layer, thus obtaining a corrosion-resistant aluminum alloy mold. Among them, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92; The plasma electrolytic oxidation process parameters include: a pulse frequency of 980 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically treating for 5 minutes at 400 V, 2 minutes at 430 V, 2 minutes at 460 V, 2 minutes at 480 V, 2 minutes at 500 V, 2 minutes at 520 V, 2 minutes at 540 V, 2 minutes at 560 V, 2 minutes at 580 V, and 2 minutes at 600 V.

[0021] Example 4: A processing technology for a corrosion-resistant aluminum alloy mold, comprising the following steps: S1: Under an argon atmosphere, add aluminum powder, vanadium powder, and 1.5 wt% stearate to a ball mill, perform ball milling with a ball-to-material ratio of 16:1, cold press the ball-milled mixed powder at a pressure of 5 GPa for 10 minutes, polish it with 1200-mesh SiC sandpaper, and heat-treat it at 150 °C to obtain an aluminum alloy mold; Among them, the mass ratio of aluminum powder to vanadium powder is 95:5; S2: After ultrasonically washing the surface of the aluminum alloy mold with ethanol, dry it with nitrogen for standby; Under an argon atmosphere, use an arc directed energy deposition process on the surface of the aluminum alloy mold to obtain an aluminum-based cladding; Among them, the wire parameters for the arc directed energy deposition process include: a diameter of 1.2 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and a mass ratio of TiC nanoparticles to AA2024 aluminum alloy of 3:97; The arc directed energy deposition process parameters include: a wire feeding speed of 130 cm / min, a deposition speed of 10 cm / min, an EP current of 110 A, an EP current of 220 A, an EN-EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 °C; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; Immerse the aluminum alloy mold with an aluminum-based cladding on its surface in boiling deionized water for 3 min, take it out, and anneal it at 170 °C for 1 h in a nitrogen atmosphere to obtain a pretreated aluminum alloy mold; Place the pretreated aluminum alloy mold in a reaction vessel, introduce a hydrogen mixed gas containing 1% HSiCl3, react at room temperature for 1 h, evacuate, purge with nitrogen to remove unreacted gases, and then perform a plasma electrolytic oxidation process, wash ultrasonically in deionized water, and dry in vacuum to obtain a corrosion-resistant protective layer and a corrosion-resistant aluminum alloy mold. Among them, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92; The plasma electrolytic oxidation process parameters include: a pulse frequency of 980 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically treating at 400 V for 5 min, 430 V for 2 min, 460 V for 2 min, 480 V for 2 min, 500 V for 2 min, 520 V for 2 min, 540 V for 2 min, 560 V for 2 min, 580 V for 2 min, and 600 V for 2 min.

[0022] Comparative Example 1: A processing process for a corrosion-resistant aluminum alloy mold, including the following steps: S1: Under an argon atmosphere, add aluminum powder, vanadium powder, and 1.5 wt% stearate to a ball mill, perform ball milling with a ball-to-material ratio of 16:1, cold press the ball-milled mixed powder at a pressure of 5 GPa for 10 min, polish it with 1200-mesh SiC sandpaper, and heat-treat it at 250 °C to obtain an aluminum alloy mold; Among them, the mass ratio of aluminum powder to vanadium powder is 97:3; S2: After ultrasonically washing the surface of the aluminum alloy mold with ethanol, dry it with nitrogen for standby; Under an argon atmosphere, use an arc-directed energy deposition process on the surface of the aluminum alloy mold to obtain an aluminum-based cladding; Among them, the wire parameters for the arc-directed energy deposition process include: a diameter of 1.2 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and a mass ratio of TiC nanoparticles to AA2024 aluminum alloy of 2:98; The arc-directed energy deposition process parameters include: a wire feeding speed of 130 cm / min, a deposition speed of 10 cm / min, an EP current of 110 A, an EP current of 220 A, an EN-EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 °C; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; Immerse the aluminum alloy mold with an aluminum-based cladding on its surface in boiling deionized water for 3 min, take it out, and anneal it at 170 °C for 1 h in a nitrogen atmosphere to obtain a pretreated aluminum alloy mold; Place the pretreated aluminum alloy mold in a reaction vessel, introduce a hydrogen mixed gas containing 1% HSiCl3, react at room temperature for 1 h, evacuate the air, purge with nitrogen to remove unreacted gases, and then carry out the plasma electrolytic oxidation process, wash it ultrasonically in deionized water, and dry it in vacuum to obtain a corrosion-resistant protective layer, thus obtaining a corrosion-resistant aluminum alloy mold. Among them, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92; The parameters for the plasma electrolytic oxidation process include: a pulse frequency of 980 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically, it is processed at 400 V for 5 min, 430 V for 2 min, 460 V for 2 min, 480 V for 2 min, 500 V for 2 min, 520 V for 2 min, 540 V for 2 min, 560 V for 2 min, 580 V for 2 min, and 600 V for 2 min.

[0023] Comparative Example 2: A processing technology for a corrosion-resistant aluminum alloy mold, comprising the following steps: S1: Under an argon atmosphere, add aluminum powder, vanadium powder, and 1.5 wt% stearate to a ball mill, and carry out ball milling with a ball-to-material ratio of 16:1. Cold press the ball-milled mixed powder at a pressure of 5 GPa for 10 min, polish it with 1200-mesh SiC sandpaper, and heat-treat it at 150 °C to obtain an aluminum alloy mold; Among them, the mass ratio of aluminum powder to vanadium powder is 97:3; S2: After ultrasonically washing the surface of the aluminum alloy mold with ethanol, dry it with nitrogen for standby; Under an argon atmosphere, use the arc-directed energy deposition process on the surface of the aluminum alloy mold to obtain an aluminum-based cladding; Among them, the wire parameters for the arc-directed energy deposition process include: a diameter of 1.2 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and a mass ratio of TiC nanoparticles to AA2024 aluminum alloy of 2:98; The parameters for the arc-directed energy deposition process include: a wire feeding speed of 130 cm / min, a deposition speed of 10 cm / min, an EP current of 110 A, an EP current of 220 A, an EN-EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 °C; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; Immerse the aluminum alloy mold with an aluminum-based cladding on its surface in boiling deionized water for 3 min, take it out, and anneal it at 170 °C for 1 h in a nitrogen atmosphere to obtain a pretreated aluminum alloy mold; Perform a plasma electrolytic oxidation process on the pretreated aluminum alloy mold, wash it ultrasonically in deionized water, and dry it in vacuum to obtain a corrosion-resistant protective layer and a corrosion-resistant aluminum alloy mold. Among them, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92; The plasma electrolytic oxidation process parameters include: a pulse frequency of 980 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically 5 min at 400 V, 2 min at 430 V, 2 min at 460 V, 2 min at 480 V, 2 min at 500 V, 2 min at 520 V, 2 min at 540 V, 2 min at 560 V, 2 min at 580 V, and 2 min at 600 V.

[0024] Comparative Example 3: A processing technology for a corrosion-resistant aluminum alloy mold, comprising the following steps: S1: Under an argon atmosphere, add aluminum powder, vanadium powder, and 1.5 wt% stearate to a ball mill, and perform ball milling with a ball-to-material ratio of 16:1. Cold-press the ball-milled mixed powder at a pressure of 5 GPa for 10 min, polish it with 1200-mesh SiC sandpaper, and perform heat treatment at 150 °C to obtain an aluminum alloy mold; Among them, the mass ratio of aluminum powder to vanadium powder is 97:3; S2: After ultrasonically washing the surface of the aluminum alloy mold with ethanol, dry it with nitrogen for standby; Under an argon atmosphere, perform an arc-directed energy deposition process on the surface of the aluminum alloy mold to obtain an aluminum-based cladding; Among them, the wire parameters for the arc-directed energy deposition process include: a diameter of 1.2 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and a mass ratio of TiC nanoparticles to AA2024 aluminum alloy of 2:98; The arc-directed energy deposition process parameters include: a wire feeding speed of 130 cm / min, a deposition speed of 10 cm / min, an EP current of 110 A, an EP current of 220 A, an EN-EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 °C; S3: Polish the surface of the aluminum alloy mold with an aluminum-based cladding, wash it ultrasonically with ethanol, and dry it with nitrogen for standby; place the aluminum alloy mold with an aluminum-based cladding on the surface in a reaction vessel, introduce a hydrogen mixed gas containing 1% HSiCl3, react at room temperature for 1 h, evacuate, purge with nitrogen to remove unreacted gases, then perform a plasma electrolytic oxidation process, wash ultrasonically in deionized water, and dry in vacuum to obtain a corrosion-resistant protective layer and a corrosion-resistant aluminum alloy mold. Among them, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:92; the plasma electrolytic oxidation process parameters include: a pulse frequency of 980 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically, treat at 400 V for 5 min, 430 V for 2 min, 460 V for 2 min, 480 V for 2 min, 500 V for 2 min, 520 V for 2 min, 540 V for 2 min, 560 V for 2 min, 580 V for 2 min, and 600 V for 2 min.

[0025] Experiment: Wear resistance test: A friction and wear test was carried out on the corrosion-resistant aluminum alloy mold using a friction and wear testing machine. A Si3N4 ball with a diameter of 3 mm and a hardness of 1300 was used as the relative friction ball. The rotation speed was 300 revolutions per minute, and the friction track radius was 3 mm. The load was 5 N, the frequency was 5 Hz, and the time was 30 min for reciprocating friction.

[0026] Corrosion resistance test: The electrochemical test was carried out in a sodium chloride solution with a mass fraction of 3.5% at room temperature using an electrochemical workstation equipped with a standard three-electrode cell system. A sample with an exposed area of 1 square centimeter was selected as the working electrode; a platinum sheet was used as the counter electrode, and a saturated calomel electrode was used as the reference electrode. The applied scanning rate was 2 mV per second.

[0027] The experimental results are shown in Table 1 below.

[0028] Table 1 Performance test data table of corrosion-resistant aluminum alloy mold

[0029] Conclusion: The corrosion-resistant aluminum alloy prepared by the present invention has excellent wear resistance and corrosion resistance.

[0030] In Comparative Example 1, the aging heat treatment temperature was too high, resulting in an increase in the grain size and a decrease in the wear and corrosion resistance.

[0031] In Comparative Example 2, the pre-passivation treatment was missing, resulting in a decrease in the bonding force of the corrosion-resistant protective layer and a decrease in the wear and corrosion resistance.

[0032] In Comparative Example 3, the hydroxylation treatment is lacking, resulting in a decrease in the bonding strength of the corrosion-resistant protective layer and a decrease in the wear and corrosion resistance.

[0033] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention.

Claims

1. A processing technology for a corrosion-resistant aluminum alloy mold, characterized in that: It includes the following steps: S1: Under an argon atmosphere, add aluminum powder, vanadium powder, and hard stearate into a ball mill for ball milling. Cold press, polish, and heat-treat the ball-milled mixed powder to obtain an aluminum alloy mold. S2: After ultrasonic washing the surface of the aluminum alloy mold with ethanol, dry it with nitrogen for standby. Under an argon atmosphere, use the arc-directed energy deposition process on the surface of the aluminum alloy mold to obtain an aluminum-based cladding layer. S3: Polish, ultrasonically wash with ethanol, and dry with nitrogen the surface of the aluminum alloy mold with an aluminum-based cladding layer for standby. Hydroxylate the aluminum alloy mold with an aluminum-based cladding layer on its surface to obtain a pretreated aluminum alloy mold. Place the pretreated aluminum alloy mold in a reaction vessel for pre-passivation treatment, then carry out the plasma electrolytic oxidation process, ultrasonically wash in deionized water, and vacuum dry to obtain a corrosion-resistant protective layer and a corrosion-resistant aluminum alloy mold.

2. The processing technology of a corrosion-resistant aluminum alloy mold according to claim 1, characterized in that: During the preparation process of the aluminum alloy mold, the mass ratio of aluminum powder to vanadium powder is (95 - 97):(3 - 5); the cold pressing pressure is 3 - 5 GPa, the cold pressing time is 10 - 15 min; the heat treatment temperature is 150 - 200 °C.

3. The processing technology of a corrosion-resistant aluminum alloy mold according to claim 1, characterized in that: During the preparation process of the aluminum-based cladding layer, the wire parameters for the arc-directed energy deposition process include: a diameter of 1.2 - 1.25 mm, a material of AA2024 aluminum alloy added with TiC nanoparticles, and the mass ratio of TiC nanoparticles to AA2024 aluminum alloy is (2 - 3):(97 - 98).

4. The processing technology of a corrosion-resistant aluminum alloy mold according to claim 1, characterized in that: During the preparation process of the aluminum-based cladding layer, the arc-directed energy deposition process parameters include: a wire feeding speed of 130 - 135 cm / min, a deposition speed of 10 - 10.1 cm / min, an EP current of 110 A, an EP current of 220 A, an EN - EP balance of 80%, an AC frequency of 100 Hz, a voltage of 12.5 V, and an interlayer temperature of 80 - 82 °C.

5. The processing technology of a corrosion-resistant aluminum alloy mold according to claim 1, characterized in that: During the preparation process of the pretreated aluminum alloy mold, the hydroxylation treatment step is to immerse the aluminum alloy mold with an aluminum-based cladding layer on its surface in boiling deionized water for 2 - 3 min, take it out, and anneal it at 170 - 175 °C for 1 - 1.5 h under a nitrogen atmosphere.

6. The processing technology of a corrosion-resistant aluminum alloy mold according to claim 1, characterized in that: During the preparation process of the corrosion-resistant protective layer, the pre-passivation treatment step is to place the pretreated aluminum alloy mold in a reaction vessel, introduce a hydrogen mixed gas containing 1 - 1.2% HSiCl3, react at room temperature for 1 - 3 h, evacuate, and purge with nitrogen to remove unreacted gases.

7. The processing technology of a corrosion-resistant aluminum alloy mold according to claim 1, characterized in that: During the preparation process of the corrosion-resistant protective layer, the electrolyte parameters for the plasma electrolytic oxidation process include: a mixed solution of sodium hydroxide, tetraethyl orthosilicate, and deionized water with a molar ratio of 1.06:1:

92.

8. The processing technology of a corrosion-resistant aluminum alloy mold according to claim 1, characterized in that: During the preparation process of the corrosion-resistant protective layer, the plasma electrolytic oxidation process parameters include: a pulse frequency of 980 - 1000 Hz, a duty cycle of 5%, and stepwise constant voltage control, specifically treating at 400 V for 5 min, 430 V for 2 min, 460 V for 2 min, 480 V for 2 min, 500 V for 2 min, 520 V for 2 min, 540 V for 2 min, 560 V for 2 min, 580 V for 2 min, and 600 V for 2 min.

9. A corrosion-resistant aluminum alloy mold prepared by the processing technology of a corrosion-resistant aluminum alloy mold according to any one of claims 1-8.

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