TWI400357B - 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 one of a surface disposed on the substrate Strengthen the film. The reinforced film includes a first alloy layer and a second alloy layer, and the first alloy layer is disposed between the surface of the substrate and the second alloy layer. The first alloy layer includes two transition metals, and the second alloy layer includes the two transition metals and carbon nitrogen elements.

A surface-strengthening substrate comprising a substrate and a reinforced film having a multilayer structure on one of the surface surfaces of the substrate. The reinforced film includes at least a transition layer and a hard layer, and the transition layer and the hard layer are sequentially disposed on the surface of the substrate. The transition layer is an alloy layer formed of two transition metals, the hard layer being an alloy layer containing the two transition metals and non-metal elements.

A surface strengthening substrate comprising a substrate and a reinforcing film disposed on a surface of the substrate. The reinforced film is an alloy film containing two transition metals, and the reinforced film includes a carbon-nitrogen element away from one side of the substrate.

A method for preparing a surface-strengthened substrate, comprising the steps of: providing a substrate; and sequentially forming a first alloy layer and a second alloy layer on one surface of the substrate by sputtering, the first alloy layer comprising Two transition metals, the second alloy layer comprising the two transition metals and carbon and nitrogen elements.

Compared with the prior art, the first alloy layer formed by the two transition metals in the reinforced membrane has good chemical stability and good affinity with the matrix, and can alleviate internal stress changes when the reinforced membrane is stressed. The bonding force between the film and the substrate is increased; and the second alloy layer formed by the two transition metals and the carbon nitrogen element has a higher hardness. Therefore, the reinforced film can be well bonded to the substrate and has a certain degree of abrasion resistance.

100‧‧‧Surface-strengthened matrix

10‧‧‧ base

20‧‧‧ Strengthening film

21‧‧‧First alloy layer

22‧‧‧Second alloy layer

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

2 is a graph showing the variation of the element content of the surface-enhanced matrix in different positions of the cross-section in FIG. 1 by Glowd ischarge optical emission spectroscopy (GD OES).

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 comprising a first alloy layer 21, a second alloy layer 22 and a finishing layer (not shown) disposed on the surface of the substrate 10.

The first alloy layer 21 is disposed between the surface of the substrate 10 and the second alloy layer 22 as a transition layer to bond the substrate 10 and the second alloy layer 22 well. The first alloy layer 21 is a nickel-chromium (Ni-Gr) alloy layer which is well 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 first alloy 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 this embodiment, the nickel-chromium alloy layer has a better bonding property with the substrate 10 and the second alloy layer 22 when the thickness is approximately 150 nm and the mass percentage of nickel is approximately 60%. hardness.

The second alloy layer 22 is disposed on a surface of the first alloy layer 21 away from the substrate 10 as a hard layer to increase the hardness of the reinforced film 20. The second alloy layer 22 is an alloy layer containing a nickel-chromium element which is well bonded to the first alloy layer 21 and has a large hardness, such as a nickel-chromium carbon (Ni-Gr-C) alloy, and a nickel-chromium nitride (Ni-Gr). -N) alloy, preferably, the second alloy layer 22 is a nickel chromium carbon nitrogen (Ni-Gr-CN) alloy layer. The chromium in the nickel-chromium carbon-nitrogen alloy layer is easily synthesized with carbon or nitrogen to form a hard chromium carbide or chromium nitride phase, and the nickel in the nickel-chromium carbon-nitrogen alloy layer is mainly used to improve the second alloy layer 22 and the first The bonding ability of the alloy layer 21. The thickness of the nickel-chromium carbon-nitrogen alloy layer is not limited and may be set according to practical applications. Typically, the nichrome layer has a thickness between 100 nanometers and 3000 nanometers. The content of nickel, chromium, carbon and nitrogen in the nickel-chromium carbon-nitrogen alloy is not limited and may be set according to practical applications. Specifically, the carbon element The mass percentage is between 1% and 50%, the nitrogen content is between 1% and 50% by mass, and the total mass percentage of the carbon nitrogen is from 1% to 90%. between. In this embodiment, when the mass percentage of the nickel element in the nickel-chromium carbon-nitrogen alloy is approximately 62%, the mass percentage of the chromium element is approximately 16%, and the mass percentage of the carbon element is approximately 12%. When the mass percentage of % and nitrogen element is approximately 10%, the second alloy layer 22 has better bonding properties and greater hardness with the first alloy layer 21 and the modified layer.

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

The modifying layer is disposed on a surface of the second alloy layer 22 away from the substrate 10 to give the surface strengthening substrate 100 a desired surface color, such as a paint, an organic layer, or the like. In the present embodiment, the modified layer itself has a large hardness and can improve the abrasion resistance of the reinforced film 20. The material for preparing the modified layer may be a chromium compound, a tungsten compound or the like, and the chromium compound includes chromium nitride, chromium carbide or a combination of chromium nitride and chromium carbide. It can be understood that since the second alloy layer 22 can achieve the purpose of protecting the substrate 10, The modification layer is optional or not selected according to actual needs.

The first alloy layer 21 (nickel-chromium alloy layer) in the reinforcing film 20 not only has good chemical stability but also has a thermal expansion coefficient similar to that of the substrate 10 and the second alloy layer 22 (nickel-chromium carbon-nitrogen alloy layer), 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 is to be noted that although the reinforcing film 20 has a multilayer structure, since the thickness of each layer is generally small, various elements penetrate each other. Therefore, it can be seen from Fig. 2 that the nickel-chromium alloy layer and the nickel-chromium carbon-nitrogen alloy layer are not strictly distributed according to the thickness, that is, the nickel-chromium alloy layer and the nickel-chromium carbon-nitrogen alloy layer do not have a strict boundary. Therefore, the reinforcing film 20 composed only of the nickel-chromium alloy layer and the nickel-chromium carbon-nitrogen alloy layer can also be regarded as a nickel-chromium alloy film as a whole. The reinforced film 20 has a large content of nickel-chromium alloy material away from one side of the substrate 10, and thus has a good affinity with the substrate 10. The reinforcing film 20 is gradually increased in carbon-nitrogen content away from one side of the substrate 10. The carbon-nitrogen element can form a hard phase with the nickel-chromium alloy, so that the reinforcing film 20 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 first alloy on one surface of the substrate 10 by sputtering. Floor 21 and a second alloy layer 22 comprising two transition metals, the second alloy layer 22 comprising the two transition metals and carbon and nitrogen elements. In this embodiment, the first alloy layer 21 is a nickel-chromium alloy layer, and the second alloy layer 22 is a nickel-chromium carbon-nitrogen alloy layer.

In step S10, the substrate 10 further includes the following step S11 before the nickel-chromium alloy layer and the nickel-chromium carbon-nitrogen alloy layer are formed on the surface thereof, and the substrate 10 is subjected to surface chemical ultrasonic cleaning; in step S12, the substrate 10 is placed. The substrate 10 is ion-cleaned with a rare gas in a vacuum environment.

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 tightly bond the nickel-chromium alloy layer and the nickel-chromium carbonitride alloy layer to the substrate 10. In the step S20, the method for forming the nichrome layer and the nichrome carbonitride layer further includes the following steps: step S21, providing a magnetron sputtered nichrome target; and step S22, turning on the magnetron splash The surface of the substrate 10 is sputtered by a nickel-chromium alloy target; and in step S23, a nitrogen-containing gas and a carbon-containing gas are introduced into the surface of the substrate 10.

In step S21, the mass percentage of nickel in the nichrome target is 20% to Between 80%.

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

In step S23, the nitrogen-containing gas is nitrogen or ammonia, and the carbon-containing gas is acetylene or methane. When the nitrogen-containing gas and the carbon-containing gas are introduced to the surface of the substrate 10, the nickel-chromium element is still sputtered from the nickel-chromium alloy target. The nickel, chromium and nitrogen-containing gas sputtered from the nichrome target react with the carbon-containing gas to form a nickel-chromium carbon-nitrogen alloy layer on the nichrome layer. That is, after the nitrogen-containing gas and the carbon-containing gas are introduced, the newly formed nickel-chromium alloy layer is doped with carbon and nitrogen elements.

The method for preparing the surface strengthening substrate 100 may further include a step S30 after the step S20: forming a chromium compound layer on the surface of the nickel-chromium carbonitride layer. The method for forming the chromium compound layer is basically the same as the principle of S20. A chromium compound layer is formed on the surface of the nickel-chromium carbon-nitrogen alloy layer by opening a magnetron sputtering pure chromium target while introducing a desired gas. The gas is selected according to actual needs. For example, if a chromium carbide layer is to be formed, a carbonaceous gas such as acetylene or methane is selected, and if a chromium nitride layer is to be formed, a nitrogen-containing gas such as nitrogen or ammonia is selected.

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. 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‧‧‧First alloy layer

22‧‧‧Second alloy layer

Claims (18)

A surface reinforced substrate comprising a substrate and a reinforced film disposed on a surface of the substrate, wherein the reinforced film comprises a first alloy layer and a second alloy layer, the first alloy layer comprising two a transition metal, the second alloy layer comprising the two transition metals and a carbon nitrogen element, the first alloy layer being disposed between the surface of the substrate and the second alloy layer. The surface strengthening 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 strengthening substrate according to claim 1, wherein the first alloy layer is a nickel-chromium alloy layer, and the second alloy layer is a nickel-chromium carbon-nitrogen alloy layer. The surface-reinforced substrate of claim 4, wherein the nickel-chromium alloy layer has a thickness of between 100 nm and 3000 nm. The surface-reinforced substrate according to claim 4, wherein the nickel-chromium alloy layer has a mass percentage of nickel of between 20% and 80%. The surface strengthening substrate according to claim 4, wherein the nickel-chromium carbon-nitrogen alloy layer has a mass percentage of carbon elements between 1% and 50%, and the nitrogen element has a mass percentage of 1%. Between 50% and the total mass percentage of carbon and nitrogen is between 1% and 90%. The surface strengthening substrate according to claim 1, wherein the reinforcing film has a thickness of between 500 nm and 5 μm. The surface strengthening substrate according to claim 4, wherein the reinforcing film further comprises a chromium compound layer disposed on a surface of the nickel chromium carbon nitride layer away from the substrate. The surface strengthening substrate according to claim 9, wherein the chromium compound comprises chromium nitride, chromium carbide or a combination of chromium nitride and chromium carbide. A surface reinforced substrate comprising a substrate and a reinforced film having a multilayer structure on one surface of the substrate, wherein the reinforced film comprises at least a transition layer and a hard layer, and the transition layer and the hard layer are sequentially disposed On the surface of the substrate; the transition layer is an alloy layer formed of two transition metals, and the hard layer is an alloy layer containing the two transition metals and non-metal elements. The surface-reinforced substrate according to claim 11, wherein the reinforcing film further comprises a modified layer containing a chromium compound disposed on a surface of the hard layer away from the substrate. A surface reinforced substrate comprising a substrate and a reinforced film disposed on a surface of the substrate, wherein the reinforced film is an alloy film containing two transition metals, and the reinforced film includes carbon away from one side of the substrate Nitrogen element. A method for preparing a surface-strengthened substrate, comprising the steps of: providing a substrate; and sequentially forming a first alloy layer and a second alloy layer on one surface of the substrate by sputtering, the first alloy layer comprising Two transition metals, the second alloy layer comprising the two transition metals and carbon and nitrogen elements. The method of producing a surface-strengthening substrate according to claim 14, wherein the first alloy layer is a nickel-chromium alloy layer, and the second alloy layer is a nickel-chromium carbon-nitrogen alloy layer. The method for preparing a surface-strengthening substrate according to claim 15, wherein the substrate further comprises the following steps: performing surface chemical ultrasonic cleaning on the substrate before forming the first alloy layer and the second alloy layer; In a vacuum environment, the substrate is ion cleaned with a rare gas. The method of producing a surface-strengthening substrate according to claim 15, wherein the temperature of the substrate is maintained between 100 degrees Celsius and 200 degrees Celsius. The method for preparing a surface-strengthened substrate according to claim 15, wherein the method for forming the nickel-chromium alloy layer and the nickel-chromium carbon-nitrogen alloy layer further comprises the steps of: providing a magnetron sputtering nickel-chromium alloy target; The surface of the substrate is sputtered by a magnetron sputtering nickel-chromium alloy target; and a nitrogen-containing gas and a carbon-containing gas are introduced into the surface of the substrate.