CN114290609A - High-strength wear-resistant aluminum mobile phone middle frame and machining process thereof - Google Patents
High-strength wear-resistant aluminum mobile phone middle frame and machining process thereof Download PDFInfo
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Abstract
The invention discloses a high-strength wear-resistant aluminum mobile phone middle frame and a processing technology thereof. The method comprises the following steps: step 1: melting, die-casting and forging the aluminum alloy raw material, and carrying out CNC rough milling and polishing to obtain an aluminum mobile phone middle frame A; step 2: sequentially carrying out alkali washing, acid washing and ultrasonic hot water treatment on the aluminum mobile phone middle frame A to carry out surface treatment; nano injection molding and annealing; CNC finish milling; obtaining an aluminum mobile phone middle frame B; and step 3: placing the aluminum mobile phone middle frame B in electrolyte for hard anodizing; sealing holes on the surface; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame. Has the advantages that: in the technical scheme, the bonding strength of the polymer after injection molding is enhanced and the yield is increased by combined treatment of alkali washing, acid washing and ultrasonic hot water treatment. Titanium sol is added into electrolyte in the hard anodizing process to increase the uniformity of surface reaction, and the surface hardness and the wear resistance are enhanced in cooperation with other components and an ozone pre-dissolving step.
Description
Technical Field
The invention relates to the technical field of mobile phone middle frames, in particular to a high-strength wear-resistant aluminum mobile phone middle frame and a processing technology thereof.
Background
In recent years, with the acceleration of the technological innovation of electronic products, the requirements of people on mobile phones are gradually increased; because of the advantages of high strength, good texture, good heat dissipation and the like of metal, the traditional mobile phone made of plastic materials is gradually replaced by the mobile phone made of metal such as aluminum alloy and the like. Among them, the middle frame of the cellular phone is also being metallized as an important member for engaging the front panel and the rear cover. The general metallized mobile phone middle frame needs to be subjected to processing steps such as die casting, CNC (computer numerical control) processing, injection molding, anodic oxidation and the like, and because the processing steps are more, compared with other metal materials, the aluminum alloy is more applied to the mobile phone middle frame due to the advantages of light weight, moderate hardness, strong processability and the like; however, when the wear-resistant and corrosion-resistant rubber is applied to the middle frame of the mobile phone, the wear-resistant and corrosion-resistant rubber has the defects of poor wear resistance, poor corrosion resistance, low hardness and the like.
In the prior art, the thickness of a surface-formed oxide film is adjusted by adjusting electrolyte and process parameters in the anodic oxidation process, so that the surface hardness, the wear resistance and the corrosion resistance of the middle frame of the mobile phone are enhanced. However, the conventional electrolyte has the problem that the oxide film formation rate is lower than the dissolution rate, so that the formed oxide film is thin and the performance is reduced; when the rate of oxide film formation is much greater than the dissolution rate, the surface is likely to form a powdery oxide film, and the surface roughness is too high. Meanwhile, because the aluminum alloy contains other metals, the surface has higher porosity and low compactness due to the uneven anodic oxidation of the surface caused by different metal activities, so that the wear resistance and the corrosion resistance are reduced; the surface cracks are generated and the yield is reduced under the promotion of long-time oxidation. In addition, in the injection molding process, the quality problems such as poor bonding property between the polymer and the plastic surface, low bonding strength, easy generation of cracks and the like result in reduction of yield. Meanwhile, the problem of acid production exists in the subsequent anodic oxidation process, and the quality and yield of the middle frame of the mobile phone are reduced.
In conclusion, the preparation of the high-strength wear-resistant aluminum mobile phone is of great significance in solving the problems.
Disclosure of Invention
The invention aims to provide a high-strength wear-resistant aluminum mobile phone middle frame and a processing technology thereof, and aims to solve the problems in the background technology.
In order to solve the technical problems, the invention provides the following technical scheme:
a processing technology of a high-strength wear-resistant aluminum mobile phone middle frame comprises the following steps:
step 1: melting, die-casting and forging the aluminum alloy raw material, and carrying out CNC rough milling and polishing to obtain an aluminum mobile phone middle frame A;
step 2: sequentially carrying out alkali washing, acid washing and ultrasonic hot water treatment on the aluminum mobile phone middle frame A to carry out surface treatment; nano injection molding and annealing; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: placing the aluminum mobile phone middle frame B in electrolyte for hard anodizing; sealing holes on the surface; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
The aluminum alloy raw material comprises the following components: according to weight percentage, 0.65 percent of Cu, 0.6 to 0.7 percent of Si, 0.05 to 0.10 percent of Mn, 0.98 percent of Mg, 0.005 percent of Ti, 0.08 percent of Fe, 0.02 percent of Zn, and the balance of Al and inevitable impurities, wherein the single impurity is less than or equal to 0.01 percent, and the total impurities are less than or equal to 0.05 percent. Including but not limited to the aluminum alloy feedstock.
Preferably, in the step 1, the die-casting temperature is 560-580 ℃; the forging temperature is 350-450 ℃.
Optimally, in the step 1, in the surface treatment process, 4-6% of sodium hydroxide solution is used for soaking for 1-3 minutes in alkaline washing; pickling and soaking for 1-3 minutes by using a 28-32% nitric acid solution; the ultrasonic hot water treatment is carried out for 2-8 minutes at the temperature of 60-70 ℃ and the ultrasonic frequency of 35-50 kHz.
Preferably, in the step 2, the raw material of the nano injection molding is a mixture of 60-70% of polymer and 30-40% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of (7-9) to 1; the other resin comprises one or more of polymethyl methacrylate, polycarbonate, polyamide resin and polyhydroxyacrylic resin; the melting temperature of the raw materials is 240-280 ℃.
Preferably, in the step 2, in the nano injection molding process, the injection molding temperature is 70-90 ℃, and the injection molding pressure is 100-120 MPa; the injection molding speed is 100-300 mm/s; the annealing temperature is 130-180 ℃, and the annealing time is 2-4 hours.
Preferably, in the step 3, the temperature is-1 to 8 ℃ and the current is 2.5 to 3.5A/dm in the hard anodic oxidation process2The voltage is 40-50V, and the time is 40-60 minutes.
Preferably, in the step 3, the raw materials of the electrolyte comprise 45-55 g/L sulfuric acid, 8-15 g/L citric acid and 5-8 g/L glycolic acid.
Preferably, in the step 3, the raw material of the electrolyte further comprises 4-6 mL/L of titanium sol.
The preparation method of the titanium sol comprises the following steps: (1) adding 80mL of ethanolamine into a reaction bottle, setting the temperature to be 10 ℃, adding 10mL of hydrogen peroxide, stirring for 20 minutes, adding 20mL of purified water and 8mL of glycerol, and stirring for reacting for 20 minutes to obtain a solution A; (2) stirring 30mL of absolute ethyl alcohol and 6mL of glycerol uniformly at 6 ℃, and adding 70mL of titanium tetrachloride for reacting for 30 minutes; setting the temperature to be-5 ℃, slowly dripping the solution A, regulating the pH value to be 3.5 within 120 minutes, and then regulating the pH value to be 9.0 within 20 minutes; heating to 70 ℃ and reacting for 30 minutes; removing chloride ions through anion exchange resin, and performing ultrafiltration concentration to 50% to obtain the titanium sol. In the titanium sol, the particle size of the titanium dioxide nano particles is about 10-15 nm.
Preferably, the electrolyte is prepared by dissolving ozone for 30-40 minutes at the temperature of-2-3 ℃.
The high-strength wear-resistant aluminum mobile phone is prepared by the processing technology of the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the bonding strength of the polymer after injection molding is enhanced and the yield is increased by combined treatment of alkali washing, acid washing and ultrasonic hot water treatment. The surface hardness and the wear resistance are enhanced by the proportion of the components in the electrolyte in the hard anodizing process.
The specific process is as follows:
(1) in the nanometer injection molding process, firstly, a passivation layer and pollutants on the surface of the aluminum alloy are removed through alkali washing and acid washing to generate nanometer pores, then the nanometer pores are subjected to ultrasonic hot water treatment, aluminum hydroxide and boehmite with different proportions are generated on the surface of the aluminum oxide in water at a certain temperature, the nanometer pores on the surface are further increased, the depth of the pores is enhanced, the bonding strength of the polymer after injection molding is enhanced, and the yield is increased. Meanwhile, residual acid is further cleaned in the ultrasonic hot water treatment process, so that the damage of acid production in the subsequent anodic oxidation process to the middle frame of the mobile phone is reduced, and the yield is increased.
Wherein the optimized ultrasonic treatment temperature is 60-70 ℃. Generally, boehmite increases in proportion to the increase in processing temperature, and the bond strength increases. However, since the boehmite particles formed are small, the particles are unstable after the temperature exceeds 70 ℃, and the surface weakly bonded ions are aggregated to the surface strongly bonded particles, so that the surface nanopores become large, the porosity is reduced, and the bonding strength is reduced. Therefore, the adhesive strength tends to decrease when the temperature exceeds 70 ℃. Meanwhile, the treatment time needs to be limited, also because the increase of the treatment time causes the surface porosity to decrease, and the pores to become large, causing the bonding strength to decrease.
In addition, the polymer in the technical scheme comprises polybutylene terephthalate and other resins containing polar groups; so that intermolecular force is generated between hydroxyl and polar groups generated by decomposing the surface aluminum hydroxide, and the bonding strength is further promoted. The injection speed limit is also set according to the hot water treatment. Because of the difference of the surface pore structure, the polymer has different embedding types under different injection molding speeds.
(2) In the scheme, the hard anodic oxidation treatment is adopted, and compared with the common anodic oxidation treatment, the oxide film formed on the surface is thicker, so that the surface hardness is higher and the wear resistance is better.
Wherein glycolic acid is added to the electrolyte in order to reduce the dissolution of the surface oxide layer and increase the thickness, thereby enhancing the wear resistance and surface hardness.
In addition, the electrolyte is subjected to ozone treatment in advance, and since the titanium sol in the scheme can reduce the anodic oxidation rate, ozone is used in advance, and the complementary titanium sol is added to cause the oxidation rate to be reduced. Meanwhile, the addition of ozone can increase the crystallization component in the oxide layer, further improve the thickness of the oxide layer and increase the performance. But the instability of ozone in acid and low dissolution rate; thus, citric acid was used as the organic acid in the protocol; because citric acid can increase the stability of ozone in acid; the dissolved amount of ozone is increased to the maximum extent.
Meanwhile, because the cathode oxidation process is a highly exothermic process, if the oxidation process is not uniform, local heat concentration can be caused, local defects (such as cracks) can be caused, and the yield is reduced; and makes the pore structure uneven, resulting in a decrease in performance. Therefore, a certain content of titanium sol is added into the electrolyte, so that the reaction uniformity in the oxidation process and the pore uniformity and compactness of the oxide film are promoted. The titanium sol is adsorbed on the surface of the middle frame, and oxygen and hydrogen ions react with the surface of the middle frame by taking the titanium sol as a medium. The sol does not affect the thickness of the oxide layer, but reduces the reaction rate due to the presence of migration resistance of oxygen and hydrogen ions. It should be noted that: the addition amount of the titanium sol needs to be certain, because too much titanium sol contains ethanol and other substances, and the titanium sol is added into the electrolyte, the conductivity is influenced, the migration of oxygen and hydrogen ions is influenced, and the film forming process of the surface oxide film is hindered. If the addition amount is too small, the surface coverage is localized, the reaction uniformity and the pore structure are affected, and the performance is reduced. Moreover, titanium nanoparticles in the titanium sol are not too large, which causes the sol layer to be too thick and not tightly arranged, reduces the compactness and uniformity of the surface oxide film, and reduces the wear resistance and corrosion resistance.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
step 1: melting and die-casting an aluminum alloy raw material at the die-casting temperature of 580 ℃, forging and pressing at the temperature of 400 ℃, and carrying out CNC rough milling and grinding to obtain an aluminum mobile phone middle frame A;
step 2: firstly, soaking an aluminum mobile phone middle frame A in a 5% sodium hydroxide solution for 2 minutes, and transferring the aluminum mobile phone middle frame A to a 30% nitric acid solution for 1 minute; washing, placing in hot water with the temperature of 65 ℃, and setting the ultrasonic frequency to be 45kHz for processing for 6 minutes; the process parameters are set as follows: the injection molding temperature is 85 ℃, and the injection molding pressure is 110 MPa; the injection molding speed is 200mm/s, nano injection molding is carried out, and annealing is carried out for 2 hours at the temperature of 150 ℃; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: (1) 50g/L of sulfuric acid, 12g/L of citric acid and 6g/L of ethanolAcid and 4.5mL/L titanium sol are sequentially added and uniformly mixed; introducing ozone for 30 minutes at 0 ℃ to obtain electrolyte; (2) placing the middle frame B of the aluminum mobile phone in electrolyte at 5 ℃ and 3.0A/dm of current2Hard anodizing for 45 minutes under the voltage of 45V; placing the mixture in hot water at the temperature of 95 ℃ and sealing the surface for 30 minutes; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the raw material of the nano injection molding is a mixture of 65% of polymer and 35% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of 8: 1; the other resin includes polymethyl methacrylate; the melting temperature of the raw materials was 260 ℃.
Example 2:
step 1: melting and die-casting an aluminum alloy raw material at the die-casting temperature of 560 ℃, forging and pressing at the temperature of 350 ℃, and carrying out CNC rough milling and grinding to obtain an aluminum mobile phone middle frame A;
step 2: firstly, soaking an aluminum mobile phone middle frame A in a 4% sodium hydroxide solution for 3 minutes, and transferring the aluminum mobile phone middle frame A to a 28% nitric acid solution for 3 minutes; washing, placing in hot water with the temperature of 60 ℃, and setting the ultrasonic frequency to be 35kHz for processing for 2 minutes; the process parameters are set as follows: the injection molding temperature is 70 ℃, and the injection molding pressure is 100 MPa; the injection molding speed is 100mm/s, nano injection molding is carried out, and annealing is carried out for 4 hours at the temperature of 130 ℃; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: (1) sequentially adding 45g/L sulfuric acid, 8g/L citric acid, 5g/L glycolic acid and 4mL/L titanium sol, and uniformly mixing; introducing ozone for 30 minutes at the temperature of minus 2 ℃ to obtain electrolyte; (2) placing the middle frame B of the aluminum mobile phone in electrolyte at the temperature of-1 ℃ and the current of 2.5A/dm2Hard anodizing for 40 minutes under the voltage of 40V; placing the mixture in hot water at the temperature of 90 ℃ and sealing the surface of the mixture for 30 minutes; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the raw material of the nano injection molding is a mixture of 60% of polymer and 40% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of 7: 1; the other resin comprises one or more of polymethyl methacrylate, polycarbonate, polyamide resin and polyhydroxyacrylic resin; the melting temperature of the raw materials was 240 ℃.
Example 3:
step 1: melting and die-casting an aluminum alloy raw material at the die-casting temperature of 580 ℃, forging and pressing at the temperature of 450 ℃, and carrying out CNC rough milling and polishing to obtain an aluminum mobile phone middle frame A;
step 2: firstly, soaking an aluminum mobile phone middle frame A in a 6% sodium hydroxide solution for 1 minute, and transferring the aluminum mobile phone middle frame A to a 32% nitric acid solution for soaking for 1 minute; washing, placing in hot water at 70 ℃, and processing for 8 minutes by setting the ultrasonic frequency at 50 kHz; the process parameters are set as follows: the injection molding temperature is 90 ℃, and the injection molding pressure is 120 MPa; the injection molding speed is 300mm/s, nano injection molding is carried out, and annealing is carried out for 2 hours at 180 ℃; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: (1) sequentially adding 55g/L sulfuric acid, 15g/L citric acid, 8g/L glycolic acid and 6mL/L titanium sol, and uniformly mixing; introducing ozone at 3 ℃ for 40 minutes to obtain electrolyte; (2) placing the middle frame B of the aluminum mobile phone in electrolyte at the temperature of 8 ℃ and the current of 3.5A/dm2Hard anodizing for 60 minutes under the voltage of 50V; placing the mixture in hot water at the temperature of 95 ℃ and sealing the surface for 30 minutes; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the raw material of the nano injection molding is a mixture of 70% of polymer and 30% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of 9: 1; the other resin comprises one or more of polymethyl methacrylate, polycarbonate, polyamide resin and polyhydroxyacrylic resin; the melting temperature of the raw materials was 280 ℃.
Comparative example 1: the hot water treatment was not performed, and the rest was the same as in example 1.
Step 1: melting and die-casting an aluminum alloy raw material at the die-casting temperature of 580 ℃, forging and pressing at the temperature of 400 ℃, and carrying out CNC rough milling and grinding to obtain an aluminum mobile phone middle frame A;
step 2: firstly, soaking an aluminum mobile phone middle frame A in a 5% sodium hydroxide solution for 2 minutes, and transferring the aluminum mobile phone middle frame A to a 30% nitric acid solution for 1 minute; washing; the process parameters are set as follows: the injection molding temperature is 85 ℃, and the injection molding pressure is 110 MPa; the injection molding speed is 200mm/s, nano injection molding is carried out, and annealing is carried out for 2 hours at the temperature of 150 ℃; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: (1) sequentially adding 50g/L sulfuric acid, 12g/L citric acid, 6g/L glycolic acid and 4.5mL/L titanium sol, and uniformly mixing; introducing ozone for 30 minutes at 0 ℃ to obtain electrolyte; (2) placing the middle frame B of the aluminum mobile phone in electrolyte at 5 ℃ and 3.0A/dm of current2Hard anodizing for 45 minutes under the voltage of 45V; placing the mixture in hot water at the temperature of 95 ℃ and sealing the surface for 30 minutes; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the raw material of the nano injection molding is a mixture of 65% of polymer and 35% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of 8: 1; the other resin includes polymethyl methacrylate; the melting temperature of the raw materials was 260 ℃.
Comparative example 2: the hot water temperature was raised to 85 ℃ and the rest was the same as in example 1.
Step 1: melting and die-casting an aluminum alloy raw material at the die-casting temperature of 580 ℃, forging and pressing at the temperature of 400 ℃, and carrying out CNC rough milling and grinding to obtain an aluminum mobile phone middle frame A;
step 2: firstly, soaking an aluminum mobile phone middle frame A in a 5% sodium hydroxide solution for 2 minutes, and transferring the aluminum mobile phone middle frame A to a 30% nitric acid solution for 1 minute; washing, placing in hot water at 85 ℃, and treating for 6 minutes by setting the ultrasonic frequency at 45 kHz; the process parameters are set as follows: the injection molding temperature is 85 ℃, and the injection molding pressure is 110 MPa; the injection molding speed is 200mm/s, nano injection molding is carried out, and annealing is carried out for 2 hours at the temperature of 150 ℃; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: (1) sequentially adding 50g/L sulfuric acid, 12g/L citric acid, 6g/L glycolic acid and 4.5mL/L titanium sol, and uniformly mixing; introducing ozone for 30 minutes at 0 ℃ to obtain electrolyte; (2) placing the middle frame B of the aluminum mobile phone in electrolyte at 5 ℃ and 3.0A/dm of current2Hard anodizing for 45 minutes under the voltage of 45V; placing the mixture in hot water at the temperature of 95 ℃ and sealing the surface for 30 minutes; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the raw material of the nano injection molding is a mixture of 65% of polymer and 35% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of 8: 1; the other resin includes polymethyl methacrylate; the melting temperature of the raw materials was 260 ℃.
Comparative example 3: the procedure of example 1 was repeated except that no other resin was added.
Step 1: melting and die-casting an aluminum alloy raw material at the die-casting temperature of 580 ℃, forging and pressing at the temperature of 400 ℃, and carrying out CNC rough milling and grinding to obtain an aluminum mobile phone middle frame A;
step 2: firstly, soaking an aluminum mobile phone middle frame A in a 5% sodium hydroxide solution for 2 minutes, and transferring the aluminum mobile phone middle frame A to a 30% nitric acid solution for 1 minute; washing, placing in hot water with the temperature of 65 ℃, and setting the ultrasonic frequency to be 45kHz for processing for 6 minutes; the process parameters are set as follows: the injection molding temperature is 85 ℃, and the injection molding pressure is 110 MPa; the injection molding speed is 200mm/s, nano injection molding is carried out, and annealing is carried out for 2 hours at the temperature of 150 ℃; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: (1) sequentially adding 50g/L sulfuric acid, 12g/L citric acid, 6g/L glycolic acid and 4.5mL/L titanium sol, and uniformly mixing; introducing ozone for 30 minutes at 0 ℃ to obtain electrolyte; (2) placing the middle frame B of the aluminum mobile phone in electrolyte at 5 ℃ and 3.0A/dm of current2Hard anodizing for 45 minutes under the voltage of 45V; placing the mixture in hot water at the temperature of 95 ℃ and sealing the surface for 30 minutes; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the raw material of the nano injection molding is a mixture of 65% of polymer and 35% of glass fiber; the polymer is polybutylene terephthalate; the melting temperature of the raw materials was 260 ℃.
Comparative example 4: the procedure of example 1 was repeated except that no titanium sol was added.
Comparative example 5: 8mL/L of titanium sol was added, and the procedure was repeated as in example 1.
Comparative example 6: 2mL/L of titanium sol was added, and the procedure was as in example 1.
Comparative example 7: the procedure of example 1 was repeated except that the titanium sol was changed to one having an average particle diameter of 30 nm.
Comparative example 8: the procedure of example 1 was repeated except that the citric acid was replaced with oxalic acid.
Comparative example 9: no ozone pretreatment is performed; the rest is the same as in example 1.
Step 1: melting and die-casting an aluminum alloy raw material at the die-casting temperature of 580 ℃, forging and pressing at the temperature of 400 ℃, and carrying out CNC rough milling and grinding to obtain an aluminum mobile phone middle frame A;
step 2: firstly, soaking an aluminum mobile phone middle frame A in a 5% sodium hydroxide solution for 2 minutes, and transferring the aluminum mobile phone middle frame A to a 30% nitric acid solution for 1 minute; washing, placing in hot water with the temperature of 65 ℃, and setting the ultrasonic frequency to be 45kHz for processing for 6 minutes; the process parameters are set as follows: the injection molding temperature is 85 ℃, and the injection molding pressure is 110 MPa; the injection molding speed is 200mm/s, nano injection molding is carried out, and annealing is carried out for 2 hours at the temperature of 150 ℃; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: (1) sequentially adding 50g/L sulfuric acid, 12g/L citric acid, 6g/L glycolic acid and 4.5mL/L titanium sol, and uniformly mixing; obtaining electrolyte; (2) placing the middle frame B of the aluminum mobile phone in electrolyte at 5 ℃ and 3.0A/dm of current2Hard anodizing for 45 minutes under the voltage of 45V; placing the mixture in hot water at the temperature of 95 ℃ and sealing the surface for 30 minutes; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
In the technical scheme, the raw material of the nano injection molding is a mixture of 65% of polymer and 35% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of 8: 1; the other resin includes polymethyl methacrylate; the melting temperature of the raw materials was 260 ℃.
Experiment: the mobile phone middle frames prepared in the embodiment and the comparative example are characterized, and comprise the peel strength of an injection molding section, the thickness of an oxide layer detected by referring to GB/T6462, the surface hardness detected by referring to GB9790 and the wear resistance detected by referring to GB/T12967.2; and calculating the reject ratio of the mobile phone middle frames prepared in one batch.
And (4) conclusion: the data from examples 1-3 show that: the mobile phone middle frame prepared by the scheme has high microhardness and high strength and wear resistance. Meanwhile, the reject ratio is as low as about 10%. The technical scheme is proved to have the realizability of industrialization.
Comparing the data for comparative examples 1-3 with the data for example 1, it is shown that: in examples 1 to 2, the peeling strength was reduced and the defective rate was increased without using the ultrasonic hot water treatment or increasing the temperature of the hot water, thereby reducing the performance. The reason is that: the ultrasonic hot water treatment process reduces the residual acid in the metal and increases the yield. While the hot water temperature relates to the ratio of the two substances of aluminum hydroxide and boehmite on the surface, different porosities and void depths are generated, the nano-boehmite rises when the temperature is increased, and unstable boehmite is gathered on stable boehmite due to higher water temperature, so that the porosity is reduced, the connection strength is reduced, and the fraction defective is increased. Meanwhile, in the embodiment 3, as other resins are not added, the polarity of the whole injection molding material is reduced, the connection strength with the surface is reduced, and the peeling strength is reduced.
Comparing the data for comparative examples 4-7 with the data for example 1, it is shown that: in the embodiment 4, the titanium sol is not added, so that the uniformity of the surface reaction is poor, defects are easy to generate, and the reject ratio is increased; and also the surface hardness is lowered due to the deterioration of uniformity. In examples 5 and 6, since the titanium sol is added too much and the titanium sol is also added with ethanol and the like, the titanium sol can affect the conductivity and further affect the migration of oxygen and hydrogen ions when being added into the electrolyte, thereby hindering the film forming process of the surface oxide film. Because the addition amount of the titanium glue is low, the surface coverage is localized, the reaction uniformity and the pore structure are influenced, and the performance is reduced. In example 7, the titanium sol had a large particle size, so that the sol layer on the surface was too thick and not tightly arranged, and the surface oxide film was less dense and less uniform, resulting in reduced wear resistance.
The data for comparative examples 8-9, compared to the data for example 1, show that: the citric acid is replaced by oxalic acid, and because the citric acid has better stability to ozone, the dissolved ozone amount is more, the reaction rate is increased, and an oxidation film is thicker and the hardness and the wear resistance are increased after the reaction is carried out in the same time; the performance was deteriorated due to the decrease in the amount of ozone in comparative example 8 and due to the absence of ozone in comparative example 9.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A processing technology of a high-strength wear-resistant aluminum mobile phone middle frame is characterized by comprising the following steps: the method comprises the following steps:
step 1: melting, die-casting and forging the aluminum alloy raw material, and carrying out CNC rough milling and polishing to obtain an aluminum mobile phone middle frame A;
step 2: sequentially carrying out alkali washing, acid washing and ultrasonic hot water treatment on the aluminum mobile phone middle frame A to carry out surface treatment; nano injection molding and annealing; CNC finish milling; obtaining an aluminum mobile phone middle frame B;
and step 3: placing the aluminum mobile phone middle frame B in electrolyte for hard anodizing; sealing holes on the surface; and obtaining the high-strength wear-resistant aluminum mobile phone middle frame.
2. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 1, is characterized in that: in the step 1, the die-casting temperature is 560-580 ℃; the forging temperature is 350-450 ℃.
3. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 1, is characterized in that: in the step 2, in the surface treatment process, soaking in an alkali washing solution of 4-6% of sodium hydroxide for 1-3 minutes; pickling and soaking for 1-3 minutes by using a 28-32% nitric acid solution; the ultrasonic hot water treatment is carried out for 2-8 minutes at the temperature of 60-70 ℃ and the ultrasonic frequency of 35-50 kHz.
4. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 1, is characterized in that: in the step 2, the raw material of the nano injection molding is a mixture of 60-70% of polymer and 30-40% of glass fiber; the polymer comprises polybutylene terephthalate and other resins in a mass ratio of (7-9) to 1; the other resin comprises one or more of polymethyl methacrylate, polycarbonate, polyamide resin and polyhydroxyacrylic resin; the melting temperature of the raw materials is 240-280 ℃.
5. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 1, is characterized in that: in the step 2, in the nano injection molding process, the injection molding temperature is 70-90 ℃, and the injection molding pressure is 100-120 MPa; the injection molding speed is 100-300 mm/s; the annealing temperature is 130-180 ℃, and the annealing time is 2-4 hours.
6. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 1, is characterized in that: in the step 3, in the hard anodic oxidation process, the temperature is-1-8 ℃, and the current is 2.5-3.5A/dm2The voltage is 40-50V, and the time is 40-60 minutes.
7. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 1, is characterized in that: in the step 3, the raw materials of the electrolyte comprise 45-55 g/L sulfuric acid, 8-15 g/L citric acid and 5-8 g/L glycolic acid.
8. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 7, is characterized in that: in the step 3, the raw material of the electrolyte also comprises 4-6 mL/L of titanium sol.
9. The processing technology of the high-strength wear-resistant aluminum mobile phone middle frame as claimed in claim 7, is characterized in that: the electrolyte is prepared by dissolving ozone for 30-40 minutes at a temperature of-2-3 ℃.
10. The high-strength wear-resistant aluminum mobile phone prepared by the processing technology of the high-strength wear-resistant aluminum mobile phone middle frame according to any one of claims 1 to 9.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115961282A (en) * | 2022-12-29 | 2023-04-14 | 东莞富盛发智能科技有限公司 | High-strength wear-resistant aluminum mobile phone middle frame and preparation method thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007320839A (en) * | 2006-06-05 | 2007-12-13 | Taki Chem Co Ltd | Alkali-type titanium oxide sol and method for producing the same |
| US20100148135A1 (en) * | 2007-04-17 | 2010-06-17 | Tayca Corporation | Surface-Coated Titanium Dioxide Sol, Process for Producing the Same and Coating Compositions Containing the Same |
| TW201402871A (en) * | 2012-07-06 | 2014-01-16 | Metal Ind Res & Dev Ct | An electrolyte for processing the surface of a metal implant and its surface treatment method by using the electrolyte |
| CN104294250A (en) * | 2014-09-04 | 2015-01-21 | 安徽华东光电技术研究所 | Solution formula and surface treatment method for conductive oxidation on aluminum alloy matrix |
| CN104607884A (en) * | 2015-02-13 | 2015-05-13 | 广东欧珀移动通信有限公司 | Processing technique of cellphone shell with metal luster |
| CN107142400A (en) * | 2017-06-02 | 2017-09-08 | 东莞宜安科技股份有限公司 | A kind of anode oxidation method of pack alloy |
| CN110219031A (en) * | 2019-06-06 | 2019-09-10 | 北京航空航天大学 | Anodic oxidation electrolyte and method, the aluminum or aluminum alloy with anode oxide film |
| CN110777415A (en) * | 2019-10-29 | 2020-02-11 | 武汉风帆电化科技股份有限公司 | Preparation method of high-temperature-resistant corrosion-resistant anodic oxide film |
| CN113423872A (en) * | 2019-02-15 | 2021-09-21 | 富士胶片株式会社 | Anodizing method and method for manufacturing anisotropic conductive member |
-
2021
- 2021-12-30 CN CN202111660539.6A patent/CN114290609B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007320839A (en) * | 2006-06-05 | 2007-12-13 | Taki Chem Co Ltd | Alkali-type titanium oxide sol and method for producing the same |
| US20100148135A1 (en) * | 2007-04-17 | 2010-06-17 | Tayca Corporation | Surface-Coated Titanium Dioxide Sol, Process for Producing the Same and Coating Compositions Containing the Same |
| TW201402871A (en) * | 2012-07-06 | 2014-01-16 | Metal Ind Res & Dev Ct | An electrolyte for processing the surface of a metal implant and its surface treatment method by using the electrolyte |
| CN104294250A (en) * | 2014-09-04 | 2015-01-21 | 安徽华东光电技术研究所 | Solution formula and surface treatment method for conductive oxidation on aluminum alloy matrix |
| CN104607884A (en) * | 2015-02-13 | 2015-05-13 | 广东欧珀移动通信有限公司 | Processing technique of cellphone shell with metal luster |
| CN107142400A (en) * | 2017-06-02 | 2017-09-08 | 东莞宜安科技股份有限公司 | A kind of anode oxidation method of pack alloy |
| CN113423872A (en) * | 2019-02-15 | 2021-09-21 | 富士胶片株式会社 | Anodizing method and method for manufacturing anisotropic conductive member |
| CN110219031A (en) * | 2019-06-06 | 2019-09-10 | 北京航空航天大学 | Anodic oxidation electrolyte and method, the aluminum or aluminum alloy with anode oxide film |
| CN110777415A (en) * | 2019-10-29 | 2020-02-11 | 武汉风帆电化科技股份有限公司 | Preparation method of high-temperature-resistant corrosion-resistant anodic oxide film |
Non-Patent Citations (1)
| Title |
|---|
| 周静: "纳米TiO_2的制备及表面改性的研究", 《科技信息(学术研究)》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115961282A (en) * | 2022-12-29 | 2023-04-14 | 东莞富盛发智能科技有限公司 | High-strength wear-resistant aluminum mobile phone middle frame and preparation method thereof |
| CN115961282B (en) * | 2022-12-29 | 2023-11-14 | 东莞富盛发智能科技有限公司 | High-strength wear-resistant aluminum mobile phone middle frame and preparation method thereof |
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|---|---|
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