TWI388423B - Surface hardening substrate and method making the same - Google Patents

Description

Surface strengthening matrix and preparation method thereof

The invention relates to a surface strengthening substrate and a method for preparing the surface strengthening substrate.

In order to protect some substrates, such as watch cases, frames, mobile phones, computers, etc., a reinforced film is often placed on the surface of these substrates to form a surface-strengthening substrate. Transition metal nitrogen compounds such as chromium nitride or transition metal carbides such as chromium carbide have a high hardness, high friction and wear resistance and good chemical stability, and are usually provided directly on the surface of the substrate to form the reinforced film. However, in practical applications, the reinforced film such as a chromium nitride film or a chromium carbide film has disadvantages such as high brittleness, high residual stress, and poor adhesion to a substrate, and both are elemental reinforced films. Therefore, as the film thickness increases and the temperature increases, these elemental strengthening films will have a large columnar crystal structure, which is prone to brittle cracking and shedding, and the surface strengthening fails.

In view of the above, it is necessary to provide a surface-strengthening substrate in which a reinforcing film is bonded to a substrate and a preparation method thereof.

A surface strengthening substrate comprising a substrate and a reinforcing film disposed on a surface of the substrate. The reinforced film includes a transition layer and a hard layer. The transition layer includes an alloy layer formed of at least two transition metals, the hard layer including a composite layer formed by compounding an alloy material containing a non-metal material and the at least two transition metals with a chromium compound material.

A method for preparing a surface-strengthened substrate, comprising the steps of: providing a substrate; and sequentially forming a transition layer and a hard layer on one surface of the substrate by sputtering, the transition layer comprising at least two transition metals The alloy layer is formed, and the hard layer comprises a composite layer formed by compounding an alloy material containing a non-metal material and the at least two transition metals with a chromium compound material.

Compared with the prior art, the transition layer formed by the two transition metals in the reinforced membrane has good chemical stability and good affinity with the matrix, can alleviate the internal stress change of the reinforced membrane under stress, and improve the film. The bonding force with the substrate; and the composite layer or the hard layer formed by combining the alloy material containing the non-metal and the at least two transition metals with the chromium compound material has a higher hardness. Therefore, the reinforced film can be well bonded to the substrate and has a certain degree of abrasion resistance.

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , an embodiment of the present invention provides a surface strengthening substrate 100 . The surface strengthening substrate 100 includes a substrate 10 and a reinforcing film 20 disposed on a surface of the substrate 10 .

The substrate 10 can be a body or a casing of various products, such as a mold, a blade, an outer casing of various electronic products, and the like. The base 10 includes a metal matrix such as a magnesium matrix, an aluminum matrix, a steel matrix, and the like, and also includes a composite matrix containing a metal material. In this embodiment, the base 10 is a steel base.

The reinforcing film 20 is used to cover the surface of the substrate 10 to isolate the surface of the substrate 10 from the environment while increasing the hardness of the surface of the substrate 10, thereby effectively protecting the substrate 10. The thickness of the reinforced film 20 can be set according to actual needs. For the general product, the thickness of the reinforced film 20 is between 500 nm and 5 microns. The reinforced film 20 is a multi-layered structure including a transition layer 21 and a hard layer 22 which are sequentially disposed on the surface of the substrate 10.

The transition layer 21 is disposed between the surface of the substrate 10 and the hard layer 22 to bond the substrate 10 and the hard layer 22 well. The transition layer 21 is a nickel-chromium (Ni-Gr) alloy layer which is bonded to the substrate 10 and has a certain hardness. The nickel in the nickel-chromium alloy layer has good toughness and high temperature stability, and has good bonding property with the metal matrix. The chromium element in the nichrome layer is used to increase the hardness of the transition layer 21. The mass percentage of nickel in the nichrome layer is approximately between 20% and 80%. The nichrome layer has a thickness between 100 nm and 3000 nm. In the present embodiment, the nickel-chromium alloy layer has a better bonding property with the substrate 10 and the hard layer 22 and has a certain hardness when the thickness is approximately 150 nm and the mass percentage of nickel is approximately 30%.

The hard layer 22 is disposed on a surface of the transition layer 21 away from the substrate 10 as a protective layer to increase the hardness of the reinforced film 20. The hard layer 22 may be an alloy material such as nickel-chromium carbon nitride (Ni-Gr-CN), nickel-chromium carbon (Ni-Gr-C), or nickel-chromium-nitrogen (Ni-Gr-N) and chromium carbide (Gr- C) or a composite layer formed by combining a chromium oxide material such as chromium nitride (Gr-N). Preferably, the hard layer 22 is a composite layer formed by combining a nickel-chromium-carbon alloy material and a chromium carbide material. The nickel-chromium carbon alloy material in the hard layer 22 has a good bonding property with the nickel-chromium alloy, and the chromium compounds in the hard layer 22 such as chromium carbide and chromium nitride have higher hardness. Therefore, the hard layer 22 formed by the combination of the nickel-chromium-carbon alloy material and the chromium compound not only has high hardness and wear resistance, but also has good bonding ability with the transition layer 21. The thickness of the hard layer 22 is not limited and may be set according to practical applications. Typically, the hard layer 22 has a thickness between 100 nanometers and 3000 nanometers. The mass percentage of the alloy material and the chromium compound in the hard layer 22 is not limited and may be set according to practical applications. Preferably, the mass percentage of the chromium compound in the hard layer 22 is approximately between 1% and 90%. When the mass percentage of the chromium compound is large, the hardness of the hard layer 22 is high, and when the mass percentage of the chromium compound is small, the affinity of the hard layer 22 to the transition layer 21 is good. Specifically, the mass percentage of the non-metallic elements such as carbon and nitrogen in the hard layer 22 is not limited, and may be set according to practical applications. In this embodiment, the mass percentage of the carbon element in the hard layer 22 is between 0 and 50%, the mass percentage of the nitrogen element is between 0 and 50%, and the carbon and nitrogen are The total mass percentage is between 1% and 90%.

The transition metal formed in the transition layer 21 and the hard layer 22 is not limited to nickel chromium, and may be an alloy composed of two or more other transition metals as long as the transition metal and the hard layer 22 in the transition layer 21 are satisfied. The transition metals in the at least two are the same to increase the affinity of the transition layer 21 and the hard layer 22, and one of the two transition metals mentioned above has a good bonding ability with the substrate 10 such as nickel or palladium. A transition metal is capable of forming a hard phase such as chromium, tungsten or the like with a non-metallic element such as carbon nitrogen to increase the hardness of the hard layer 22. The transition metal may also be rhodium, cobalt, cobalt, titanium, cadmium or zirconium.

The transition layer 21 (nickel-chromium alloy layer) in the reinforced film 20 has not only good chemical stability but also similarity to the substrate 10 and the hard layer 22 (composite layer formed by combining a nickel-chromium-carbon alloy material and chromium carbide). The coefficient of thermal expansion is such that when the surface-strengthening substrate 100 is heated, the internal stress change when the reinforcing film 20 is stressed can be effectively alleviated, thereby improving the bonding force between the reinforcing film 20 and the substrate 10 and improving the wear resistance of the substrate 10. Please refer to FIG. 2 , which is a graph showing the variation of the element content of the surface strengthening substrate 100 at different positions in the cross section in the embodiment. As can be seen from the figure, the transition of each element in each region is relatively stable, thereby effectively improving the adhesion between the reinforced film 20 and the substrate 10. It can also be seen from the figure that the transition layer 21 and the hard layer 22 in the reinforced film 20 do not have a boundary line in a strict sense, and the reinforced film 20 can be regarded as a composite film as a whole, and the composite film is The content of the nickel-chromium alloy material near one side of the substrate 10 is relatively large, so that it has a good affinity with the substrate 10, and the composite film is gradually increased in content of non-metal elements such as carbon away from the side of the substrate 10, the carbon element. The hard phase may be formed with the nickel-chromium alloy, or the hardened chromium carbide may be formed with pure chromium, so that the composite film has a large hardness away from one side of the substrate 10.

The embodiment of the present invention further provides a method for preparing the surface strengthening substrate 100, which specifically includes the following steps: Step S10, providing a substrate 10; and Step S20, sequentially forming a transition layer 21 on one surface of the substrate 10 by sputtering. And a hard layer 22, the transition layer 21 comprises an alloy layer formed of at least two transition metals, the hard layer 22 comprising a composite material comprising a non-metallic material and the at least two transition metals and a chromium compound material A composite layer formed. In this embodiment, the transition layer 21 is a nickel-chromium alloy layer, and the hard layer 22 is a composite layer formed by combining a nickel-chromium-carbon alloy material and chromium carbide.

In the step S10, the substrate 10 further comprises the following steps: forming a nickel-chromium alloy layer on the surface thereof and a composite layer formed by combining the nickel-chromium-carbon alloy material and the chromium carbide material. Step S11, performing surface chemical ultrasonic cleaning on the substrate 10. In step S12, the substrate 10 is placed in a vacuum environment, and the substrate 10 is ion-washed with a rare gas.

In step S11, the solvent for cleaning the substrate 10 may be an organic solvent such as acetone or absolute ethanol. In step S12, the substrate 10 can be placed in a vacuum metal sputtering machine having a vacuum environment, maintaining a vacuum of about 3.0 x 10 ^-5 Torr, and bombarding the substrate with high purity argon for 3 to 10 minutes.

In step S20, the temperature of the substrate 10 is controlled between 100 degrees Celsius and 200 degrees Celsius to closely bond the nickel-chromium alloy layer and the composite layer formed by the combination of the nickel-chromium-carbon alloy material and the chromium carbide with the substrate 10. In the step S20, the forming method of the transition layer 21 further includes the following steps:

Step S21, providing a magnetron sputtering alloy target formed of the at least two transition metals;

In step S22, the magnetron sputtering alloy target is turned on to sputter the surface of the substrate 10.

In step S21, when the alloy target is a nichrome target, the mass percentage of nickel in the nichrome target is between 20% and 80%.

In step S22, the bias voltage of the vacuum metal sputtering machine is set between -100 volts and -300 volts, and when the magnetron sputtering alloy target is sputtered for 20 minutes to 60 minutes, the substrate 10 is turned on. The surface is formed with a layer of alloy between 100 nm and 3000 nm.

In the step S20, the method for forming the hard layer 22 further includes the following steps:

Step S23, providing a magnetron sputtering alloy target formed by the at least two transition metals and a magnetron sputtering chromium target formed by pure chromium;

Step S24, introducing a carbon-containing gas, a nitrogen-containing gas or simultaneously introducing a carbon-containing gas and a nitrogen-containing gas onto the surface of the substrate 10;

In step S25, the magnetron sputtering alloy target and the magnetron sputtering sputtering target are alternately turned on to sputter the surface of the substrate.

In step S24, the carbon-containing gas includes acetylene or methane or the like, and the nitrogen-containing gas includes nitrogen or ammonia.

In step S25, when the alloy target is turned on, the alloy material is sputtered from the alloy target, and the alloy material reacts with a carbon-containing gas, a nitrogen-containing gas, or a gas containing carbon and nitrogen, thereby forming a blend. An alloy material having carbon, nitrogen or carbon and nitrogen. When the chromium target is turned on, the chromium reacts with a carbon-containing gas, a nitrogen-containing gas, or a gas containing carbon and nitrogen, thereby forming a chromium carbide, a chromium nitride material, or a chromium carbide and chromium nitride material. The magnetron sputtering alloy target and the chromium target are alternately opened, so that the formed alloy material is compounded with the chromium compound material, and a composite layer formed by combining the alloy material and the chromium compound material is formed on the alloy layer.

When the alloy target is a nickel-chromium alloy target, and the gas in step S24 is a carbon-containing gas. At this time, in step S25, the nichrome material is sputtered from the nichrome target and reacted with the carbon-containing gas to form a nickel-chromium carbon alloy material. When the chromium target is turned on, the chromium reacts with a carbon-containing gas to form a chromium carbide material. The magnetron sputtering nickel-chromium alloy target and the chromium target are alternately turned on, so that the formed nickel-chromium-carbon alloy material is combined with the chromium carbide material, and a nickel-chromium-carbon alloy material and a chromium carbide material are formed on the nickel-chromium alloy layer. Composite layer.

When the alloy target is a nickel-chromium alloy target, and a nitrogen-containing gas such as nitrogen or ammonia is simultaneously introduced in step S24. At this time, in step S25, the nickel-chromium alloy material reacts with the carbon-containing gas and the nitrogen-containing gas to form a nickel-chromium carbon-nitrogen alloy material, and the chromium reacts with the carbon-containing gas and the nitrogen-containing gas to form chromium carbide. , chromium nitride materials. Thereby, a composite layer formed by combining a nickel-chromium carbon-nitrogen alloy material with chromium carbide and chromium nitride materials is formed on the nickel-chromium alloy layer.

In the method for preparing the surface strengthening substrate 100, the reinforcing film 20 can be formed by sputtering, and does not require complicated chemical methods such as chemical deposition, and the process is simple and easy to operate, and the surface of the substrate 10 is also cut. There are no special requirements.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by those skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100‧‧‧Surface-strengthened matrix

10‧‧‧ base

20‧‧‧ Strengthening film

21‧‧‧Transition layer

22‧‧‧ Hard layer

FIG. 1 is a schematic structural view of a surface strengthening substrate according to an embodiment of the present invention.

Fig. 2 is a graph showing the change of the element content of the surface-enhanced matrix in different positions of the cross-section in Fig. 1 by Glow Discharge Optical Emission Spectroscopy (GD OES).

100‧‧‧Surface-strengthened matrix

10‧‧‧ base

20‧‧‧ Strengthening film

21‧‧‧Transition layer

22‧‧‧ Hard layer

Claims (13)

A surface reinforced substrate comprising a substrate and a reinforced film disposed on a surface of the substrate, wherein the reinforced film comprises a transition layer and a hard layer, the transition layer comprising a transition metal comprising at least two transition metals An alloy layer comprising a composite layer formed by compounding an alloy material containing a non-metal material and the at least two transition metals with a chromium compound material. The surface-reinforced substrate according to claim 1, wherein the substrate is a metal substrate. The surface-strengthening substrate of claim 1, wherein the transition metal comprises nickel, chromium, ruthenium, cobalt, manganese, titanium, tungsten, palladium, cadmium or zirconium. The surface-reinforced substrate according to claim 1, wherein the mass percentage of the chromium compound material in the hard layer is approximately between 1% and 90%. The surface strengthening substrate according to claim 1, wherein the transition layer comprises a nickel-chromium alloy layer composed of two transition metals of nickel and chromium. The surface-reinforced substrate according to claim 5, wherein the nickel-chromium alloy layer has a thickness of between 100 nm and 3000 nm. The surface-reinforced substrate according to claim 5, wherein the nickel-chromium alloy layer has a mass percentage of nickel of between 20% and 80%. The surface-reinforced substrate of claim 5, wherein the non-metallic material in the hard layer comprises carbon, nitrogen or a combination of carbon and nitrogen. The surface strengthening substrate according to claim 5, wherein the chromium compound comprises chromium nitride, chromium carbide, or a combination of chromium nitride and chromium carbide. The surface strengthening substrate according to claim 5, wherein the hard layer has a mass percentage of carbon elements between 0 and 50%, and the nitrogen element has a mass percentage of 0 to 50%. And the total mass percentage of the carbon and nitrogen is between 1% and 90%. A method for preparing a surface strengthened substrate, comprising the steps of:
Providing a substrate; and sequentially forming a transition layer and a hard layer on one surface of the substrate by sputtering, the transition layer comprising an alloy layer formed of at least two transition metals, the hard layer including A composite layer formed by combining a metal material and an alloy material of the at least two transition metals with a chromium compound material. The method for preparing a surface-strengthening substrate according to claim 11, wherein the method for forming the transition layer further comprises the following steps:
Providing a magnetron sputtering alloy target formed of the at least two transition metals; and opening the magnetron sputtering alloy target to sputter the surface of the substrate. The method for preparing a surface-strengthening substrate according to claim 11, wherein the method for forming the hard layer further comprises the following steps:
Providing a magnetron sputtering alloy target formed of the at least two transition metals and a magnetron sputtering chromium target formed of pure chromium;
A surface of the substrate is subjected to a carbon-containing gas, a nitrogen-containing gas or a carbon-containing gas and a nitrogen-containing gas; and the magnetron sputtering alloy target and the magnetron sputtering chromium target are alternately opened to sputter the surface of the substrate.