TWI477621B - Housing and method for making the same - Google Patents

Description

Housing and method of manufacturing same

The present invention relates to a housing and a method of manufacturing the same, and more particularly to a housing of aluminum or aluminum alloy and a method of manufacturing the same.

Aluminum or aluminum alloys are currently widely used in the aerospace, aerospace, automotive and microelectronics industries. However, the standard electrode potential of aluminum or aluminum alloy is very low, and the corrosion resistance is poor, and exposure to the natural environment causes rapid surface corrosion.

Methods for improving the corrosion resistance of aluminum or aluminum alloys generally result in a protective coating on the surface. Conventional anodizing, electrodeposition, chemical conversion film technology, and surface treatment methods for aluminum or aluminum alloys such as electroplating have disadvantages such as complicated production process, low efficiency, and serious environmental pollution.

Vacuum coating (PVD) is a clean film forming technique. However, since the standard electrode potential of aluminum or aluminum alloy is very low, and the PVD coating itself inevitably has minute pores, the PVD coating formed on the surface of the aluminum or aluminum alloy is prone to electrochemical corrosion, resulting in the PVD coating. The corrosion resistance of the layer is lowered, and the improvement of the corrosion resistance of the aluminum or aluminum alloy is limited.

In view of this, a housing of aluminum or aluminum alloy having better corrosion resistance is provided.

In addition, a method of manufacturing the above casing is also provided.

A casing comprising an aluminum or aluminum alloy substrate, the casing further comprising an aluminum film and an anti-corrosion film sequentially formed on the aluminum or aluminum alloy substrate, the anti-corrosion film being an alumina gradient film doped with a ruthenium metal ion The atomic percentage of oxygen in the alumina gradient film is gradually increased from a direction close to the aluminum or aluminum alloy matrix to a direction away from the aluminum or aluminum alloy matrix, and the doping metal ion is doped by ion implantation.

A method of manufacturing a housing, comprising the steps of:

Providing an aluminum or aluminum alloy substrate;

Magnetron sputtering an aluminum film on the surface of the aluminum or aluminum alloy substrate;

Magnetron sputtering an alumina gradient film on an aluminum film, the atomic percentage of oxygen in the gradient film of the aluminum oxide is increased from a direction close to the aluminum or aluminum alloy matrix to a direction away from the aluminum or aluminum alloy matrix;

The ruthenium metal ions are ion-implanted into the alumina gradient film to form an anti-corrosion film.

In the method for manufacturing a casing according to the present invention, an aluminum film and an anti-corrosion film are sequentially formed on an aluminum or aluminum alloy substrate, and the anti-corrosion film is an alumina gradient film doped with yttrium (Gd) metal ions by ion implantation. The composite film layer of the aluminum film and the anti-corrosion film can significantly improve the corrosion resistance of the casing, and the manufacturing process of the casing is simple and almost no environmental pollution.

Referring to FIG. 1 , a housing 10 according to a preferred embodiment of the present invention includes an aluminum or aluminum alloy substrate 11 , an aluminum film 13 sequentially formed on the surface of the aluminum or aluminum alloy substrate 11 , and an anti-corrosion film 15 . The aluminum oxide gradient film is doped with cerium metal ions, and the cerium metal ions are doped by ion implantation.

The anti-corrosion film 15 has a thickness of 0.5 to 2.0 μm. The anticorrosive film 15 is formed by a magnetron sputtering coating method.

The aluminum film 13 is formed to enhance the bonding force between the anti-corrosion film 15 and the aluminum or aluminum alloy substrate 11. The aluminum film 13 has a thickness of 100 to 300 nm.

The manufacturing method of the housing 10 mainly includes the following steps:

An aluminum or aluminum alloy substrate 11 is provided which can be obtained by press forming having the structure of the casing 10 to be produced.

The aluminum or aluminum alloy substrate 11 is placed in an ultrasonic cleaner containing an ethanol or acetone solution for vibration cleaning to remove impurities and oil stains on the surface of the aluminum or aluminum alloy substrate 11. After cleaning, dry and set aside.

The surface of the aluminum or aluminum alloy substrate 11 subjected to the above treatment is subjected to argon plasma cleaning to further remove the oil stain on the surface of the aluminum or aluminum alloy substrate 11 to improve the adhesion of the surface of the aluminum or aluminum alloy substrate 11 to the subsequent coating.

A coating machine 100 is provided. The vacuum coating machine 100 includes a coating chamber 20 and a vacuum pump 30 connected to the coating chamber 20. The vacuum pump 30 is used to evacuate the coating chamber 20. The coating chamber 20 is provided with a turret (not shown) and a relatively disposed two-aluminum target 22, and the turret drives the aluminum or aluminum alloy base 11 to revolve along a circular trajectory 21, and the aluminum or aluminum alloy substrate 11 is along the trajectory. It also rotates when it is 21 revolutions.

The specific operation and process parameters of the plasma cleaning may be: vacuuming the coating chamber 20 to a background vacuum of 8.0×10 ⁻³ Pa, and applying a flow rate of 300 to 500 sccm (standard state ML/min). An argon gas (working gas) having a purity of 99.999% is introduced into the chamber 20, and a bias voltage of -300 to -800 V is applied to the aluminum or aluminum alloy substrate 11, and a high-frequency voltage is formed in the coating chamber 20, so that The argon gas produces an argon plasma to physically bombard the surface of the aluminum or aluminum alloy substrate 11 to achieve the purpose of cleaning the surface of the aluminum or aluminum alloy substrate 11. The argon plasma cleaning time is 3 to 10 minutes.

An aluminum film 13 and an anti-corrosion film 15 are sequentially formed on the surface of the aluminum or aluminum alloy substrate 11 by magnetron sputtering. The process parameter for forming the aluminum film 13 is: after the plasma cleaning is completed, high-purity argon gas (99.999%) is passed through 100~300sccm, the aluminum target 22 is turned on, and the power of the aluminum target 22 is set to 2~8kw, and the aluminum or aluminum is adjusted. The aluminum alloy substrate 11 has a bias voltage of -300 to -500 V, and an aluminum film 13 is deposited on the surface of the aluminum or aluminum alloy substrate 11 for 5 to 10 minutes.

An anti-corrosion film 15 is prepared. The anti-corrosion film 15 is an aluminum oxide gradient film doped with yttrium (Gd) metal ions, and the doping metal ion is doped by ion implantation.

The preparation process of the alumina gradient film: using argon gas as the working gas, introducing a reaction gas oxygen having an initial flow rate of 10-20 sccm into the coating chamber, and applying a bias of -150 to -500 V on the aluminum or aluminum alloy substrate 11. In the process of depositing the alumina gradient film, the flow rate of oxygen is increased by 10-20 sccm every 10-15 min, so that the atomic percentage of O atom in the anti-corrosion film 15 is close to the aluminum or aluminum alloy substrate 11 The direction increases away from the direction of the aluminum or aluminum alloy substrate 11. The deposition time is 30~90min.

The alumina gradient film may form an Al-O phase during its formation, enhancing the density of the alumina gradient film to improve the corrosion resistance of the casing 10.

The atomic percentage of O in the alumina gradient film is increased in a gradient from the aluminum or aluminum alloy substrate 11 to the direction away from the aluminum or aluminum alloy substrate 11, which can reduce the lattice between the anti-corrosion film 15 and the aluminum film 13. The degree of matching facilitates the transfer of residual stress generated during the sputtering of the alumina gradient film toward the aluminum or aluminum alloy substrate 11; and because of the plasticity deposited between the alumina gradient film and the aluminum or aluminum alloy substrate 11 The good aluminum film 13 can improve the interface mismatch between the alumina gradient film and the aluminum or aluminum alloy substrate 11. When the residual stress in the alumina gradient film is large, the aluminum film 13 and aluminum or The local plastic deformation of the aluminum alloy base 11 realizes the release of residual stress, thereby reducing the residual stress in the alumina gradient film, making the casing 10 less susceptible to stress corrosion, thereby improving the corrosion resistance of the casing 10. The stress corrosion refers to a metal failure phenomenon caused by residual or/and external stress and corrosive medium.

After the deposition of the alumina gradient film is completed, the base metal ions are implanted on the surface of the alumina-resistant gradient film. The process of implanting the base metal ions is: placing the aluminum or aluminum alloy substrate 11 plated with the aluminum film 13 and the aluminum oxide gradient film in a high-current metal ion implanter (MEVVA) (not shown). The ion implanter uses a base metal target, which first ionizes the base metal to generate a base metal ion vapor, and accelerates the high pressure electric field to form the base metal ion vapor with tens of thousands or even millions of electrons. The strontium metal ion beam of volt energy is injected into the surface of the alumina gradient film, and physically reacts with atoms or molecules in the surface of the alumina gradient film and the surface thereof, so that the aluminum oxide gradient film is implanted with bismuth metal ions to form The anti-corrosion layer 15.

The parameters for injecting bismuth metal ions are: the vacuum degree of the ion implanter is 1×10 ^-4 Pa, the ion source voltage is 30~100kV, the ion beam current intensity is 0.1~5mA, and the control cesium metal ion implantation dose is 1×10 ¹⁶ Ion/cm ² to 1 × 10 ¹⁸ ions/cm ² .

The ruthenium (Gd) metal ions are metallurgically bonded to atoms in the alumina gradient film, and therefore, the implanted ruthenium metal ions are not easily detached, and since they are formed under high energy ion implantation conditions, the ruthenium (Gd) is formed. After the metal is implanted into the alumina gradient film, it is formed into an amorphous layer. Since the amorphous structure has the characteristics of isotropy, no grain boundary at the surface, no dislocation, segregation, homogeneous system, etc., ion implantation (Gd) The alumina gradient film after the metal ions makes the casing 10 less likely to form a corrosive microbattery in the corrosive medium, and the possibility of electrochemical corrosion is small, and the corrosion resistance of the casing 10 is greatly improved.

The method for preparing the housing 10 and the housing 10 will be described below in conjunction with specific embodiments:

Example 1

Plasma cleaning: argon gas flow rate is 280sccm, aluminum or aluminum alloy substrate 11 has a bias voltage of -300V, and plasma cleaning time is 9 minutes;

Sputtering aluminum film 13: using aluminum target 22 as a target, argon gas is introduced into 100 sccm, the power of the aluminum target 22 is set to 2 kw, and the bias of the aluminum or aluminum alloy substrate 11 is set to -500 V, and deposition is performed for 5 minutes;

The anti-corrosion layer 15 is prepared: a sputtering alumina gradient film, argon gas as a working gas, a flow rate of 100 sccm, oxygen as a reaction gas, and an initial flow rate of oxygen of 10 sccm, respectively, is applied on the aluminum or aluminum alloy substrate 11 - 500V bias; the flow rate of oxygen is increased by 10sccm every 10min, and the deposition time is controlled to 30min;

Injecting ruthenium metal ions into the alumina gradient film: setting the vacuum degree to 1×10 ^-4 Pa, the ion source voltage to 30 kV, the ion beam current intensity to 0.1 mA, and controlling the ruthenium metal ion implantation dose to be 1×10 ¹⁶ ions/cm ² .

Example 2

Plasma cleaning: argon gas flow rate is 230sccm, metal aluminum or aluminum alloy substrate 11 has a bias voltage of -480V, and plasma cleaning time is 7 minutes;

Sputtering aluminum film 13: using aluminum target 22 as a target, argon gas 200sccm, aluminum target 22 power is set to 5kw, aluminum or aluminum alloy substrate 11 is set to -400V, deposition for 7 minutes;

The anti-corrosion layer 15 is prepared: a sputtering alumina gradient film, argon gas as a working gas, a flow rate of 200 sccm, oxygen as a reaction gas, and an initial flow rate of oxygen of 15 sccm, respectively, is applied on the aluminum or aluminum alloy substrate 11 - 300V bias; the flow rate of oxygen is increased by 15sccm every 12min, and the deposition time is controlled to 60min;

The ruthenium metal ions were implanted into the alumina gradient film: the degree of vacuum was set to 1 × 10 ^-4 Pa, the ion source voltage was 60 kV, the ion beam current intensity was 2 mA, and the ruthenium metal ion implantation dose was controlled at 1 × 10 ¹⁷ ions/cm ² .

Example 3

Plasma cleaning: argon gas flow rate is 160sccm, aluminum or aluminum alloy substrate 11 has a bias voltage of -400V, and plasma cleaning time is 6 minutes;

Sputtered aluminum film 13: with aluminum target 22 as a target, argon gas 300sccm, set aluminum target 22 power is 8kw, set aluminum or aluminum alloy substrate 11 bias is -300V, deposition 10 minutes;

The anti-corrosion layer 15 is prepared: a sputtering alumina gradient film, argon gas as a working gas, a flow rate of 300 sccm, oxygen as a reaction gas, and an initial flow rate of oxygen of 20 sccm, respectively, is applied on the aluminum or aluminum alloy substrate 11 - 150V bias; the flow rate of oxygen is increased by 20sccm every 15min, and the deposition time is controlled to 90min;

The process parameters for injecting ruthenium metal ions into the alumina gradient film are: setting the vacuum degree to 1×10 ^-4 Pa, the ion source voltage to 100 kV, the ion beam current intensity to 5 mA, and controlling the bismuth metal ion implantation dose to 1×10 ¹⁸ ions/ Cm ² .

In the manufacturing method of the casing 10 according to the preferred embodiment of the present invention, an aluminum film 13 and an anti-corrosion film 15 are sequentially formed on the aluminum or aluminum alloy substrate 11, and the anti-corrosion film 15 is an alumina gradient film, and the ion implantation is performed by ruthenium ( Gd) metal ions. The composite film layer composed of the aluminum film 13 and the anti-corrosion film 15 remarkably improves the corrosion resistance of the casing 10, and the manufacturing process is simple and almost free from environmental pollution.

10. . . case

11. . . Aluminum or aluminum alloy substrate

13. . . Aluminum film

15. . . Anti-corrosion film

100. . . Coating machine

20. . . Coating chamber

twenty one. . . Trajectory

twenty two. . . Aluminum target

30. . . Vacuum pump

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view showing a housing of a preferred embodiment of the present invention.

2 is a top plan view of the coating machine used in the manufacturing process of the housing of FIG. 1.

10. . . case

11. . . Aluminum or aluminum alloy substrate

13. . . Aluminum film

15. . . Anti-corrosion film

Claims (8)

A casing comprising an aluminum or aluminum alloy substrate, the improvement comprising: the casing further comprising an aluminum film and an anti-corrosion film sequentially formed on the aluminum or aluminum alloy substrate, the anti-corrosion film being an alumina gradient film, which is doped a heterogeneous metal ion having an atomic percentage of oxygen in the gradient film of the alumina increasing from a direction close to the aluminum or aluminum alloy matrix to a direction away from the aluminum or aluminum alloy matrix, wherein the doping metal ion is doped by ion implantation . The casing of claim 1, wherein the corrosion-resistant film has a thickness of 0.5 to 2.0 μm. The casing of claim 1, wherein the aluminum film has a thickness of 100 to 300 nm. A method of manufacturing a housing, comprising the steps of:
Providing an aluminum or aluminum alloy substrate;
Magnetron sputtering an aluminum film on the surface of the aluminum or aluminum alloy substrate;
Magnetron sputtering an alumina gradient film on an aluminum film, the atomic percentage of oxygen in the gradient film of the aluminum oxide is increased from a direction close to the aluminum or aluminum alloy matrix to a direction away from the aluminum or aluminum alloy matrix;
The ruthenium metal ions are ion-implanted into the alumina gradient film to form an anti-corrosion film. The method for manufacturing a casing according to claim 4, wherein the process parameter of the magnetron sputtering the alumina gradient film is: using argon as a working gas, the flow rate is 100-300 sccm, and reacting with oxygen Gas, set the initial flow rate of oxygen to 10~20sccm, apply a bias voltage of -150~-500V on the aluminum or aluminum alloy substrate, increase the flow rate of oxygen by 10~20sccm every deposition for 10~15min, and control the deposition time to 30~ 90min. The method for manufacturing a casing according to claim 4, wherein the process parameter for injecting the base metal ion into the alumina gradient film is: setting the degree of vacuum to be 1×10 ^-4 Pa, and the ion source voltage is 30 to 100 kV, The ion beam current intensity is 0.1 to 5 mA, and the ruthenium metal ion implantation dose is controlled to be between 1 × 10 ¹⁶ ions/cm ² and 1 × 10 ¹⁸ ions/cm ² . The method for manufacturing a casing according to claim 4, wherein the process parameter for depositing the aluminum film is: taking an aluminum target as a target, and vacuuming the coating chamber to set a vacuum of 8.0×10 ^{− 3} Pa, argon gas 100~300sccm, open the aluminum target, set the aluminum target power to 2~8kw, set the aluminum or aluminum alloy substrate bias voltage to -300~-500V, deposit 5~10 minutes. The method of manufacturing a casing according to claim 4, wherein the method of manufacturing the casing further comprises the step of plasma-cleaning the aluminum or aluminum alloy substrate before depositing the aluminum film.