CN109440069B

CN109440069B - Multi-arc ion plating for preparing Ti/TiN superhard nano multilayer film with small modulation period

Info

Publication number: CN109440069B
Application number: CN201910043083.5A
Authority: CN
Inventors: 孙珲; 郑小龙; 宋淑梅; 杨田林; 王宝铭; 王昆仑; 杨波波
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2019-01-17
Filing date: 2019-01-17
Publication date: 2021-01-26
Anticipated expiration: 2039-01-17
Also published as: CN109440069A

Abstract

The invention discloses a method for preparing a small modulation period Ti/TiN superhard nano multilayer film by multi-arc ion plating. The preparation method of the film comprises the following steps: placing a titanium metal deposition target in the cavity in a one-way manner; taking the hard alloy and the single-side polished monocrystalline silicon wafer as sample substrates for film growth; extracting air in the cavity to enable the interior of the cavity to be in a vacuum state; heating the interior of the cavity in a vacuum state, introducing argon gas with the purity higher than an argon gas threshold value, and performing glow discharge cleaning for a first time period; reducing the flow of argon to a first flow rate; starting a titanium metal deposition target, and carrying out bombardment cleaning on the sample substrate under negative bias for a second time period; depositing a titanium layer with a first deposition thickness in advance as a transition layer; argon and nitrogen are respectively and periodically introduced into the cavity, and titanium sublayers and titanium nitride sublayers are alternately deposited to form the multi-arc ion plating preparation of the Ti/TiN superhard nano multilayer film with small modulation period, so that the service life of a product prepared based on the TiN film is prolonged.

Description

Multi-arc ion plating for preparing Ti/TiN superhard nano multilayer film with small modulation period

Technical Field

The invention relates to the field of titanium nitride film preparation, in particular to a small modulation period Ti/TiN superhard nano multilayer film prepared by multi-arc ion plating.

Background

Titanium Nitride (TiN) hard films have the advantages of high hardness, small friction coefficient, good wear resistance, light gold color and the like, and are commonly used as protective films, decorative films and the like; for example, the TiN film plated on the surface of the high-speed steel drill bit can obviously improve the service life of the drill bit; the surface of a daily stainless steel article is plated with a TiN golden decorative coating film. The preparation of TiN single-layer films by utilizing the multi-arc ion plating technology is a common and mature technology and is widely applied at present, however, with the development of modern industry, the properties of the TiN single-layer films in the aspects of hardness, adhesive force, wear resistance and the like gradually cannot meet the use requirements, and the service life of the TiN single-layer films is short, so that the service life of products made of the TiN films is short.

Disclosure of Invention

The invention aims to provide a multi-arc ion plating preparation method of a small modulation period Ti/TiN superhard nano multilayer film, so as to solve the problem of short service life of a product made of a TiN film.

In order to achieve the purpose, the invention provides the following scheme:

a preparation device for preparing a small modulation period Ti/TiN superhard nano-multilayer film by multi-arc ion plating comprises: a chamber, a cylindrical device and a titanium metal deposition target;

the cylindrical device and the titanium metal deposition target are vertically arranged in the cavity in a one-way mode, and the cylindrical device corresponds to the titanium metal deposition target; the cylindrical device is provided with a sample substrate outside, can rotate and is used for periodically concentrating the retention process of residual gas in a space away from the target surface of the sample substrate during the film coating process; the titanium metal deposition target is used for bombard cleaning the sample substrate.

A preparation method for preparing small modulation period Ti/TiN superhard nano-multilayer films by multi-arc ion plating is applied to a preparation device for preparing small modulation period Ti/TiN superhard nano-multilayer films by multi-arc ion plating, the preparation device for preparing small modulation period Ti/TiN superhard nano-multilayer films by multi-arc ion plating comprises a cavity, a cylindrical device and a titanium metal deposition target, and the cylindrical device and the titanium metal deposition target are arranged inside the cavity;

the cylindrical device and the titanium metal deposition target are vertically arranged in the cavity in a one-way mode, and the cylindrical device corresponds to the titanium metal deposition target; the cylindrical device is provided with a sample substrate outside, can rotate and is used for periodically concentrating the retention process of residual gas in a space away from the target surface of the sample substrate during the film coating process; the titanium metal deposition target is used for bombard cleaning the sample substrate;

the preparation method for preparing the small modulation period Ti/TiN superhard nano-multilayer film by multi-arc ion plating comprises the following steps:

placing a titanium metal deposition target in the cavity in a one-way mode;

taking the hard alloy and the single-side polished monocrystalline silicon wafer as sample substrates for film growth;

extracting air in the cavity to enable the interior of the cavity to be in a vacuum state;

heating the interior of the cavity in a vacuum state, introducing argon gas with the purity higher than an argon gas threshold value, and performing glow discharge cleaning for a first time period;

reducing the flow of argon to a first flow rate;

starting the titanium metal deposition target, and carrying out bombardment cleaning on the sample substrate under negative bias for a second time period;

depositing a titanium layer with a first deposition thickness in advance as a transition layer;

and respectively and periodically introducing argon and nitrogen into the cavity, and alternately depositing titanium sublayers and titanium nitride sublayers to form the multi-arc ion plating to prepare the Ti/TiN superhard nano multilayer film with the small modulation period.

Optionally, the center distance between the upper target and the lower target of the titanium metal deposition target is 250mm, and the arc current range is 70-75A.

Optionally, the vacuum degree in the vacuum state is 2.0-3.0 × 10^-2Pa; the flow velocity of the argon introduced into the reactor is 150cm higher than the argon purity threshold³Min; the first time period is 10-15 min.

Optionally, the first flow rate is 100cm³/min。

Optionally, the negative bias range is 400-600V, and the second time period is 10-15 min.

Optionally, the first deposition thickness is 50-70 nm.

Optionally, argon and nitrogen are respectively and periodically introduced into the cavity, and the flow velocity of the argon is 100cm³Min, flow rate of said nitrogen gasAt a speed of 90cm³/min。

Optionally, during the process of respectively and periodically introducing argon and nitrogen into the cavity and alternately depositing the titanium sub-layer and the titanium nitride sub-layer, the negative bias voltage of the deposition substrate is 200-300V; the duty cycle is 40%; the vacuum degree during the titanium layer plating is 2.3-2.7 multiplied by 10 < -1 > Pa; the vacuum degree during the titanium nitride layer plating is 1.2-1.5 multiplied by 10-1 Pa.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects: the invention provides a device and a method for preparing a small modulation period Ti/TiN superhard nano multilayer film by multi-arc ion plating.

Meanwhile, compared with a TiN single-layer film, the multi-arc ion plating preparation of the small modulation period Ti/TiN superhard nano-multilayer film greatly improves the performances in the aspects of hardness, adhesive force, wear resistance and the like, prolongs the service life of the multi-arc ion plating preparation of the small modulation period Ti/TiN superhard nano-multilayer film, and further improves the service life of products made of the TiN film.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a structural diagram of a device for preparing a small modulation period Ti/TiN superhard nano-multilayer film by multi-arc ion plating provided by the invention;

FIG. 2 is a flow chart of a method for preparing a small modulation period Ti/TiN superhard nano-multilayer film by multi-arc ion plating provided by the invention;

FIG. 3 is a comparative electron microscope image of TiN single-layer film and Ti/TiN nano-multilayer film provided by the present invention; wherein, fig. 3 (a) is an electron microscope image of the TiN single-layer film provided by the invention, and fig. 3 (b) is an electron microscope image of the Ti/TiN nano-multilayer film provided by the invention;

FIG. 4 is an electron microscope image of Ti/TiN nano-multilayer films with different modulation periods provided by the present invention; wherein, fig. 4 (a) is an electron microscope image of the Ti/TiN nano-multilayer film with the modulation period of 39.2nm provided by the present invention, fig. 4 (b) is an electron microscope image of the Ti/TiN nano-multilayer film with the modulation period of 20.3nm provided by the present invention, fig. 4 (c) is an electron microscope image of the Ti/TiN nano-multilayer film with the modulation period of 13.2nm provided by the present invention, fig. 4 (d) is an electron microscope image of the Ti/TiN nano-multilayer film with the modulation period of 7.5nm provided by the present invention, and fig. 4 (e) is an electron microscope image of the Ti/TiN nano-multilayer film with the modulation period of 5.2nm (theoretical value) provided by the present invention;

FIG. 5 is a schematic diagram of the film-based bonding force of the Ti/TiN nano-multilayer film provided by the present invention;

FIG. 6 is a structural diagram of a Ti/TiN multilayer nano-film provided by the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

In recent years, the research of preparing Ti/TiN nano-multilayer films by utilizing the multi-arc ion plating technology mainly focuses on the influence of the modulation period size on the performance of the films, and the minimum modulation period of the preparation is 34 nm. Researches show that the reduction of the modulation period obviously improves other mechanical properties of the film except the hardness, so that the ultrahard film with excellent comprehensive performance can be obtained by preparing the Ti/TiN nano multilayer film with the small modulation period by utilizing the multi-arc ion plating technology; however, the multi-arc ion plating technology has high plating rate and residual gas cannot be pumped out of the cavity in time, so that the preparation of the nano multilayer film with a small modulation period by using the technology is difficult; at present, the research of preparing the nano multilayer film with a small modulation period (less than or equal to 20 nm) by utilizing the multi-arc ion plating technology is not seen.

According to the invention, the sample holder of the cavity is improved, so that the problem of large interface mixing layer caused by excessive residual gas and plating rate is avoided to a certain extent. The side view of the coating apparatus and the configuration of the sample holder (cylindrical apparatus) are shown in FIG. 1.

The coating process is mainly concentrated in a sector area right in front of the target due to the constraint of the magnetic field. The target position is placed in one direction, the self-made cylindrical device is installed, the coating area can be effectively restrained, the coating process is reasonably controlled, the retention process of residual gas is periodically concentrated in the space of the sample far away from the target surface, and the rotating speed is reasonably controlled according to the retention time of the measured gas, so that the uniform and compact Ti/TiN nano multilayer film with the small modulation period is obtained.

Fig. 2 is a flow chart of a preparation method for preparing a small modulation period Ti/TiN ultra-hard nano-multilayer film by multi-arc ion plating, and as shown in fig. 2, the preparation method for preparing the small modulation period Ti/TiN ultra-hard nano-multilayer film by multi-arc ion plating comprises the following steps:

step 201: and placing the titanium metal deposition target in the cavity in a unidirectional mode.

The invention adopts the multi-arc ion plating technology to prepare Ti/TiN nano multilayer films with different modulation periods. Two round Ti metal deposition targets with the purity of 99.99 percent are adopted and are placed in a single direction, the center distance between the upper target and the lower target is 250mm, and the arc current is 70-75A.

Step 202: the hard alloy and the single-side polished monocrystalline silicon wafer are used as sample substrates for film growth.

Selecting a hard alloy and a single-side polished monocrystalline silicon (100) sheet as a sample substrate for film growth, wherein the hard alloy substrate is a block of 15 multiplied by 4mm, and grinding and polishing the hard alloy substrate on an LCZMP-2 automatic metallographic specimen grinding and polishing machine until the surface roughness is R_aAbout 0.8 μm; and ultrasonically cleaning the sample substrate in deionized water, acetone and absolute ethyl alcohol for 10-15min in sequence, drying and then putting into a cavity.

In the preparation process, the revolution of the worktable is 10 r/min.

Step 203: and extracting air in the cavity to ensure that the interior of the cavity is in a vacuum state.

Firstly, the vacuum degree of the cavity is pumped to 2.0-3.0 multiplied by 10^-2Pa, preheating to 200-300 ℃, introducing high-purity argon at 150cm3/min, and performing glow discharge cleaning for 10-15 min.

Step 204: and heating the interior of the cavity in a vacuum state, introducing argon gas with the purity higher than an argon gas threshold value, and performing glow discharge cleaning for a first time period.

Step 205: the flow of argon is reduced to a first flow rate.

The flow of argon is reduced to 100cm³The Ti target is turned on, and the sample is bombarded and cleaned for 10-15 minutes under the negative bias of 400-600V.

Step 206: and starting the titanium metal deposition target, and performing bombardment cleaning on the sample substrate under negative bias for a second time period.

Step 207: a titanium layer of a first deposition thickness is previously deposited as a transition layer.

And a Ti layer with the thickness of 50-70nm is deposited in advance to serve as a transition layer so as to improve the film-substrate bonding force.

Step 208: and respectively and periodically introducing argon and nitrogen into the cavity, and alternately depositing titanium sublayers and titanium nitride sublayers to form the multi-arc ion plating to prepare the Ti/TiN superhard nano multilayer film with the small modulation period.

Alternately depositing Ti and TiN sublayers by periodically switching on and off argon and nitrogen flows, wherein the flow of the argon gas is 100cm³Min, nitrogen flow 90cm³And/min. In the experiment, a substrate was depositedNegative bias voltage of 200-300V, duty ratio of 40%, vacuum degree of Ti plating of 2.3-2.7 × 10^-1Pa, vacuum degree of TiN plating of 1.2-1.5 × 10^-1Pa。

By adjusting the coating time, 5 Ti/TiN nano-multilayer films with different cycles were prepared, and table 1 is a comparison table of the 5 Ti/TiN nano-multilayer films with different cycles provided by the present invention, as shown in table 1.

TABLE 1

Sample numbering	Ti/TiN Single layer coating time(s)	Single layer thickness (nm) of Ti/TiN	Modulation period (nm)	Number of cycles	Total thickness of film (mum)
						1#	Ti48/TiN144	10.9/28.3	39.2	30	1.34
2#	Ti24/TiN72	5.4/14.9	20.3	60	1.35
						3#	Ti12/TiN36	3.2/10.0	13.2	120	1.32
4#	Ti9/TiN21	1.7/5.8	7.5	180	1.33
						5#	Ti6/TiN18	--	5.2	240	1.27

The device and the method for preparing the small modulation period Ti/TiN superhard nano-multilayer film based on the multi-arc ion plating are further explained by specific embodiments.

Example one

Two circular surface deposition targets with the purity of 99.99 percent are adopted and are arranged in a single direction, the center distance between the upper target and the lower target is 250mm, and the arc current is 70A. Selecting a hard alloy and a single-side polished monocrystalline silicon (100) sheet as a substrate for film growth, wherein the hard alloy substrate is a block with the thickness of 15 multiplied by 4mm, and grinding and polishing the block on an LCZMP-2 automatic metallographic specimen grinding and polishing machine until the surface roughness is R_a0.8 μm. And ultrasonically cleaning the sample in deionized water, acetone and absolute ethyl alcohol for 10min in sequence, drying and then putting the sample into a cavity. In the preparation process, the revolution of the worktable is 10 r/min. Before the experimentFirstly, the vacuum degree of the cavity is pumped to 2 multiplied by 10^-2Pa, preheating to 300 ℃, introducing high-purity argon 150cm3/min, cleaning the substrate by glow discharge for 10-15min, and reducing the argon flow to 100cm³The Ti target was turned on and the sample was bombarded at a negative bias of 600V for ten minutes. A50 nm Ti layer is deposited in advance to serve as a transition layer to improve the film-substrate binding force, and a Ti sublayer and a TiN sublayer are alternately deposited by periodically switching on and off argon and nitrogen gas flows, wherein the Ti plating time is 48S, and the TiN plating time is 144S. In the experiment, the negative bias voltage of the deposition substrate is 200V, the duty ratio is 40%, and the vacuum degree of Ti plating is 2.3-2.7 multiplied by 10^- ¹Pa, vacuum degree of TiN plating of 1.2-1.5 × 10^-1Pa. Finally, the nano-multilayer film with the cycle number of 30 and the single cycle thickness of 39.2nm is prepared.

Example two

Two circular surface deposition targets with the purity of 99.99 percent are adopted and are arranged in a single direction, the center distance between the upper target and the lower target is 250mm, and the arc current is 70A. Selecting a hard alloy and a single-side polished monocrystalline silicon (100) sheet as a substrate for film growth, wherein the hard alloy substrate is a block with the thickness of 15 multiplied by 4mm, and grinding and polishing the block on an LCZMP-2 automatic metallographic specimen grinding and polishing machine until the surface roughness is R_a0.8 μm. And ultrasonically cleaning the sample in deionized water, acetone and absolute ethyl alcohol for 10min in sequence, drying and then putting the sample into a cavity. In the preparation process, the revolution of the worktable is 10 r/min. Before the experiment, the vacuum degree of the cavity is firstly pumped to 2 multiplied by 10^-2Pa, preheating to 300 ℃, and introducing high-purity argon for 150cm³A/min, glow discharge cleaning the substrate for 10-15min, and reducing the argon flow to 100cm³The Ti target was turned on and the sample was bombarded at a negative bias of 600V for ten minutes. A50 nm Ti layer is deposited in advance to serve as a transition layer to improve the film-substrate binding force, and a Ti sublayer and a TiN sublayer are alternately deposited by periodically switching on and off argon and nitrogen gas flows, wherein the Ti plating time is 24S, and the TiN plating time is 72S. In the experiment, the negative bias voltage of the deposition substrate is 200V, the duty ratio is 40%, and the vacuum degree of Ti plating is 2.3-2.7 multiplied by 10^-1Pa, vacuum degree of TiN plating of 1.2-1.5 × 10^-1Pa. Finally, the nano multilayer film with the cycle number of 60 and the single cycle thickness of 20.3nm is prepared.

EXAMPLE III

Adopts two purities of99.99% of the round surface deposition targets are arranged in a single direction, the center distance between the upper target and the lower target is 250mm, and the arc current is 70A. Selecting a hard alloy and a single-side polished monocrystalline silicon (100) sheet as a substrate for film growth, wherein the hard alloy substrate is a block with the thickness of 15 multiplied by 4mm, and grinding and polishing the block on an LCZMP-2 automatic metallographic specimen grinding and polishing machine until the surface roughness is R_a0.8 μm. And ultrasonically cleaning the sample in deionized water, acetone and absolute ethyl alcohol for 10min in sequence, drying and then putting the sample into a cavity. In the preparation process, the revolution of the worktable is 10 r/min. Before the experiment, the vacuum degree of the cavity is firstly pumped to 2 multiplied by 10^-2Pa, preheating to 300 ℃, introducing high-purity argon 150cm3/min, cleaning the substrate by glow discharge for 10-15min, and reducing the argon flow to 100cm³The Ti target was turned on and the sample was bombarded at a negative bias of 600V for ten minutes. A50 nm Ti layer is deposited in advance to serve as a transition layer to improve the film-substrate binding force, and a Ti sublayer and a TiN sublayer are alternately deposited by periodically switching on and off argon and nitrogen gas flows, wherein the Ti plating time is 12S, and the TiN plating time is 36S. In the experiment, the negative bias voltage of the deposition substrate is 200V, the duty ratio is 40%, and the vacuum degree of Ti plating is 2.3-2.7 multiplied by 10^-1Pa, vacuum degree of TiN plating of 1.2-1.5 × 10^-1Pa. Finally, the nano-multilayer film with the cycle number of 120 and the single cycle thickness of 13.2nm is prepared.

Example four

Two circular surface deposition targets with the purity of 99.99 percent are adopted and are arranged in a single direction, the center distance between the upper target and the lower target is 250mm, and the arc current is 70A. Selecting a hard alloy and a single-side polished monocrystalline silicon (100) sheet as a substrate for film growth, wherein the hard alloy substrate is a block with the thickness of 15 multiplied by 4mm, and grinding and polishing the block on an LCZMP-2 automatic metallographic specimen grinding and polishing machine until the surface roughness is R_a0.8 μm. And ultrasonically cleaning the sample in deionized water, acetone and absolute ethyl alcohol for 10min in sequence, drying and then putting the sample into a cavity. In the preparation process, the revolution of the worktable is 10 r/min. Before the experiment, the vacuum degree of the cavity is firstly pumped to 2 multiplied by 10^-2Pa, preheating to 300 ℃, introducing high-purity argon 150cm3/min, cleaning the substrate by glow discharge for 10-15min, and reducing the argon flow to 100cm³The Ti target was turned on and the sample was bombarded at a negative bias of 600V for ten minutes. Pre-depositing 50nm Ti layer as transition layer to raise the film-base binding forceAnd (3) switching argon and nitrogen flows to alternately deposit a Ti sublayer and a TiN sublayer, wherein the Ti plating time is 9S, and the TiN plating time is 21S. In the experiment, the negative bias voltage of the deposition substrate is 200V, the duty ratio is 40%, and the vacuum degree of Ti plating is 2.3-2.7 multiplied by 10^-1Pa, vacuum degree of TiN plating of 1.2-1.5 × 10^-1Pa. Finally, the nano multilayer film with the cycle number of 180 and the single cycle thickness of 7.5nm is prepared.

EXAMPLE five

Two circular surface deposition targets with the purity of 99.99 percent are adopted and are placed in a single direction, the center distance between an upper target and a lower target is 250mm, and the arc current is 70A; selecting a hard alloy and a single-side polished monocrystalline silicon (100) sheet as a substrate for film growth, wherein the hard alloy substrate is a block with the thickness of 15 multiplied by 4mm, and grinding and polishing the block on an LCZMP-2 automatic metallographic specimen grinding and polishing machine until the surface roughness is R_aAbout 0.8 μm; ultrasonically cleaning a sample in deionized water, acetone and absolute ethyl alcohol for 10min in sequence, drying and then putting the sample into a cavity; in the preparation process, the revolution of the worktable is 10 r/min; before the experiment, the vacuum degree of the cavity is firstly pumped to 2 multiplied by 10^-2Pa, preheating to 300 ℃, introducing high-purity argon 150cm3/min, cleaning the substrate by glow discharge for 10-15min, and reducing the argon flow to 100cm³Starting a Ti target, and bombarding the sample for ten minutes under the negative bias of 600V; a50 nm Ti layer is deposited in advance to serve as a transition layer to improve the film-substrate binding force, and a Ti sublayer and a TiN sublayer are alternately deposited by periodically switching on and off argon and nitrogen gas flows, wherein the Ti plating time is 6S, and the TiN plating time is 18S. In the experiment, the negative bias voltage of the deposition substrate is 200V, the duty ratio is 40%, and the vacuum degree of Ti plating is 2.3-2.7 multiplied by 10^-1Pa, vacuum degree of TiN plating of 1.2-1.5 × 10^-1Pa. Finally, the nano-multilayer film with the cycle number of 240 and the single cycle thickness of 5.2nm is prepared.

For comparison, the conventional TiN single-layer film is prepared by the multi-arc ion plating technology, which comprises the following steps:

two round surface Ti metal deposition targets with the purity of 99.99 percent are adopted, and the arc current is 70A; selecting a hard alloy and a single-side polished monocrystalline silicon (100) sheet as a substrate for film growth, wherein the hard alloy substrate is a block with the thickness of 15 multiplied by 4mm, and grinding and polishing the block on an LCZMP-2 automatic metallographic specimen grinding and polishing machine until the surface roughness is R_aAbout 0.8 μm; sequentially ultrasonically cleaning the sample in deionized water, acetone and absolute ethyl alcohol for 10min, drying and then placing the sample into a cavity; in the preparation process, the revolution of the worktable is 10 r/min. Before the experiment, the vacuum degree of the cavity is firstly pumped to 2.0 multiplied by 10^-2Pa, preheating to 300 ℃, and introducing high-purity Ar of 100cm³Performing bombardment cleaning on the sample for 10 minutes under the negative bias of 600V; a Ti layer with the thickness of 50nm is deposited in advance to be used as a transition layer so as to improve the film-substrate binding force; after the deposition of the transition layer, the introduction of Ar gas was stopped, and the introduction was stopped for 90cm³N of/min₂Depositing TiN; the negative bias voltage of the deposition substrate in the experimental process is 200V, and the duty ratio is 40%.

FIG. 3 is an electron microscope image comparison diagram of the TiN monolayer film and the Ti/TiN nano-multilayer film provided by the invention, as shown in FIG. 3, the performance test and comparison of the Ti/TiN nano-multilayer film and the TiN film are as follows:

the WS-2005 coating adhesion automatic scratch tester is adopted to test the coating adhesion, the loading load is 70N, the loading rate is 70N/min, and the scratch length is 7 mm.

(1) Hardness, modulus and H/E comparison

The hardness and modulus of the coating are tested by adopting a TTX-NHT2 type nano indenter produced by Antopab Switzerland, a pressure head is a Berkovich triangular pyramid, the loading load is 5mN, the loading rate is 2000nm/min, the pressing depth is controlled to be 10% of the coating thickness, 5 points are measured, the average value is taken, and a table 2 is a nano multilayer film hardness change table with different modulation periods provided by the invention and is shown in a table 2.

TABLE 2

FIG. 4 is an electron microscope image of Ti/TiN nano-multilayer films with different modulation periods provided by the invention, as shown in FIG. 4, the hardness of 5 nano-multilayer films gradually increases and then decreases with the reduction of the modulation period, the hardness reaches 42.9GPa at the highest and 26.9GPa at the lowest, both of which are higher than 25.5GPa of a single-layer TiN film, and the modulus gradually increases and then decreases with the reduction of the modulation period, and is 357.88GPa at the highest and 294.52GPa at the lowest. The H/E value is increased and then decreased, the maximum is 0.1198, the minimum is 0.0921, and the hardness and the wear resistance of the Ti/TiN nano multilayer film are all obviously improved compared with the single-layer TiN film, which is 0.084.

Compared with a TiN film, the Ti/TiN nano multilayer film provided by the invention has obviously improved hardness, wear resistance and the like, the maximum hardness reaches 42.9GPa, and is far greater than 25.5GPa of a TiN single-layer film; the adhesive force, the wear resistance and the like are also obviously improved.

The Ti/TiN nano multilayer film provided by the invention has the advantages that the film hardness is improved to different degrees according to different modulation periods, the maximum hardness reaches 42.9GPa which is far higher than 25.5GPa of a TiN single-layer film, and the hardness is improved by 68.23%.

The H/E value is the ratio of hardness to modulus, the ratio reflects the wear resistance of the film to a certain extent, and the higher the ratio is, the better the wear resistance is; the H/E value of the TiN single-layer film is 0.084, the H/E value of the Ti/TiN nano multilayer film is 0.1198 to the maximum extent, and compared with the TiN single-layer film, the H/E value is improved by 42.62 percent.

The existence of multiple interfaces and the addition of soft Ti layers can effectively release the stress of the film, and in addition, the pinning effect of energy-carrying ions on a substrate in the multi-arc ion plating technology plays a positive role in improving the film-substrate binding force of the Ti/TiN nano multilayer film, so that the film can still maintain larger film-substrate binding force (58 +/-0.9) N while obtaining ultrahigh hardness.

(2) Adhesion testing and comparison

FIG. 5 is a schematic diagram of the film-based bonding force of the Ti/TiN nano-multilayer film provided by the present invention, as shown in FIG. 5, the adhesion force of the Ti/TiN nano-multilayer film with a multilayer structure is significantly greater than the adhesion force of a single layer of TiN by 29N; when the modulation period is 39.2nm, the film has the maximum film-based bonding force value (62 +/-1) N; however, when the modulation period is reduced to 20.3nm, the actual thickness of the Ti sublayer is reduced due to the shortened deposition time of the Ti sublayer and the increased proportion of the mixed layer, the stress capable of bearing is reduced, and the film-substrate bonding force is reduced; however, as the modulation period was reduced from 20.3nm to 7.5nm, the film-based bonding force of the thin film was increased to (58. + -. 0.9) N.

FIG. 6 is a structural diagram of a Ti/TiN nano-multilayer film provided by the present invention, as shown in FIG. 6, the minimum modulation period of the Ti/TiN nano-superhard film prepared by the present invention reaches 7.5nm, and the thickness of single period Ti/TiN is 1.7nm/5.8nm, respectively.

The invention relates to a Ti/TiN superhard nano multilayer film. The Ti/TiN nano multilayer film has obviously better performances of hardness, toughness, adhesive force and the like than TiN single-layer films, can replace the TiN single-layer films, is used in the fields of high-speed cutting tools and the like, has better performances of hardness, wear resistance and the like compared with the traditional TiN films, and can further prolong the service life of the high-speed cutting tools.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for those skilled in the art, according to the idea of the present invention, any modification, equivalent replacement, improvement, etc. made in the specific embodiments and application ranges, such as using multi-arc ion plating, magnetron sputtering, evaporation, chemical vapor deposition, atomic layer deposition, electroplating, etc. to prepare metal titanium, iron, nickel, chromium, manganese, zinc, copper, aluminum, magnesium, calcium, cobalt, silver, zirconium, niobium, hafnium, tantalum, lead, antimony, tungsten, rubidium, molybdenum, gallium, indium, silicon, ytterbium, germanium, rhenium, europium, etc. and metal oxide, nitride, carbide, oxynitride, carbonitride, etc. alternating multilayer films thereof, and the implementation cases for improving the hardness, adhesion, toughness, wear resistance, and product service life of the film shall be included in the protection scope of the present invention. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. A preparation method for preparing small modulation period Ti/TiN superhard nano-multilayer films by multi-arc ion plating is characterized in that the preparation method for preparing the small modulation period Ti/TiN superhard nano-multilayer films by multi-arc ion plating is applied to a preparation device for preparing the small modulation period Ti/TiN superhard nano-multilayer films by multi-arc ion plating, the preparation device for preparing the small modulation period Ti/TiN superhard nano-multilayer films by multi-arc ion plating comprises a cavity, a cylindrical device and a titanium metal deposition target, and the cylindrical device and the titanium metal deposition target are arranged in the cavity;

the cylindrical device and the titanium metal deposition target are vertically arranged in the cavity in a one-way mode, and the cylindrical device corresponds to the titanium metal deposition target; the cylindrical device is provided with a sample substrate outside, can rotate and is used for periodically concentrating the retention process of residual gas in a space of the sample substrate away from a target surface in the film coating process, and reasonably controlling the rotating speed according to the retention time of the measured gas so as to obtain a uniform and compact Ti/TiN superhard nano-multilayer film with a small modulation period; the titanium metal deposition target is used for bombard cleaning the sample substrate;

placing a titanium metal deposition target in the cavity in a one-way mode;

heating the interior of the cavity in a vacuum state, introducing high-purity argon, and performing glow discharge cleaning for a first time period;

reducing the flow of argon to a first flow rate;

respectively and periodically introducing argon and nitrogen into the cavity, and alternately depositing titanium sublayers and titanium nitride sublayers, wherein the flow velocity of the argon is 100cm³Min, the flow velocity of the nitrogen is 90cm³Min, the negative bias of the deposition substrate is 200-300V; the duty cycle is 40%; the degree of vacuum in the titanium plating was 2.3X 10^-1-2.7×10^-1Pa; the degree of vacuum during the titanium nitride layer plating was 1.2X 10^-1-1.5×10^-1Pa, forming the Ti/TiN superhard nano multilayer film with small modulation period prepared by multi-arc ion plating.

2. The method for preparing a small modulation period Ti/TiN superhard nano-multilayer film by multi-arc ion plating according to claim 1, wherein the center distance between an upper target and a lower target of the titanium metal deposition target is 250mm, and the arc current ranges from 70A to 75A.

3. The method for preparing Ti/TiN superhard nano-multilayer film with small modulation period by multi-arc ion plating according to claim 1, wherein the vacuum degree in the vacuum state is 2.0 x 10^-2-3.0×10^-2Pa; the flow velocity of the high-purity argon is 150cm³Min; the first time period is 10-15 min.

4. The method for preparing Ti/TiN superhard nano-multilayer film with small modulation period by multi-arc ion plating according to claim 1, wherein the first flow velocity is 100cm³/min。

5. The method for preparing a small modulation period Ti/TiN superhard nano-multilayer film by multi-arc ion plating according to claim 1, wherein the negative bias voltage in the second time period for bombardment cleaning of the sample substrate is within the range of 400-600V, and the second time period is 10-15 min.

6. The method of claim 1, wherein the first deposition thickness is 50-70 nm.