Method and device for preparing titanium nitride coating on TC4 alloy surface

Abstract

The invention relates to a method and device for preparing a titanium nitride coating on a TC4 alloy surface, and the method comprises the following steps: firstly, enabling TiCl4 to react with NH3 at 1500-2000 DEG C to generate TiN; secondly, under the condition of 1500-2000 DEG C, the gasified Si and the TiN generated in the first step are subjected to a replacement reaction, and Ti is generated; the method comprises the following steps: preparing a TC4 alloy from Ti and NH3, then reacting the generated Ti with NH3 at a low temperature of 400-700 DEG C to generate TiN and H2, and realizing adhesion and combination of TiN and H2 on the surface of the TC4 alloy, and in the deposition process, promoting adhesion of TiN and realizing grain refinement on the surface of the TC4 alloy by utilizing a spinning roller 9 and hydrogenation reaction; according to the scheme, high-temperature treatment at the temperature of 4000 DEG C or above is avoided, the mode that Ti is replaced from TiN is indirectly adopted, the subsequent process that TiN is attached to and combined with the surface of the TC4 alloy is carried out at the low temperature, energy is saved through the design of the method, the process difficulty and the complexity of a device are reduced, and the situation that the performance structure of a TC4 alloy body is damaged is avoided.

Description

Technical Field

[0001] The invention discloses a method and a device for preparing a titanium nitride coating on the surface of a TC4 alloy, belonging to the technical field of thermal processing. Background Art

[0002] Titanium nitride is a common titanium alloy surface strengthening layer that can improve the strength and wear resistance of the titanium alloy surface. Titanium nitride on the titanium alloy surface can be achieved by ion nitriding technology, but ion nitriding technology requires special equipment, and the temperature of the entire process is high, which can easily destroy the overall mechanical properties of the titanium alloy. While strengthening the surface, it reduces the strength and fatigue life of the titanium alloy. Therefore, ion nitriding technology has certain limitations. At the same time, as a non-stress heat treatment strengthening method, ion nitriding technology requires time to adjust the thickness and density of the nitriding layer, resulting in a waste of resources and low economic efficiency. Summary of the invention

[0003] The present invention is designed to address the above-mentioned existing technical situation and provides a method and device for preparing a titanium nitride coating on the surface of a TC4 alloy. The purpose of the present invention is to avoid the high-temperature heat treatment strengthening method of more than 4000°C in the ion nitriding technology, so that the titanium nitride coating on the surface of the TC4 alloy can be prepared under low temperature conditions. At the same time, energy is saved and the process difficulty and device complexity are reduced.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] The technical solution of the present invention proposes a method for preparing a titanium nitride coating on the surface of a TC4 alloy, characterized in that the steps of the method are as follows:

[0006] Step 1: At 1500-2000℃, TiCl 4 With NH 3 Reaction occurs to generate TiN;

[0007] Step 2: Under the condition of 1500-2000° C., the vaporized Si undergoes a substitution reaction with the TiN generated in step 1 to generate Ti;

[0008] Step 3: At 400-700°C, the Ti generated in step 2 is reacted with NH 3 Reaction occurs to generate TiN and H 2 , and realize TiN and H 2 Adhesion and bonding on the surface of TC4 alloy;

[0009] Step 4: Apply pressure to the surface of the TC4 alloy to cause it to undergo plastic deformation, thereby completing surface strengthening of the TC4 alloy.

[0010] Technical solution of the present invention

[0011] The technical solution of the present invention also provides a device for realizing the method of preparing titanium nitride coating on the surface of TC4 alloy, characterized in that: the device comprises a Si raw material tank 1, a TiCl 4 Raw material tank 3 and NH 3 Raw material tank 5, Si raw material tank 1 and NH 3 The raw material tank 5 is connected to the TiCl 4 Raw material tank 3 is connected, TiCl 4 The raw material tank 3 is connected to one end of the low temperature reaction box 7 through a one-way valve 2. 3 The raw material tank 5 is also connected to the above-mentioned end of the low-temperature reaction box 7 through the one-way valve 2 and the pipeline 6. The other end of the low-temperature reaction box 7 is connected to the deposition box 4. A heating sleeve 8 is arranged on the periphery of the low-temperature reaction box 7 and the deposition box 4. A TC4 alloy billet 10 is placed in the deposition box 4. The TC4 alloy billet 10 can rotate along its own central axis. A rotating wheel 9 is arranged on the inner wall of the deposition box 4. The lower end of the rotating wheel 9 acts on the surface of the TC4 alloy billet 10 to cause it to undergo plastic deformation.

[0012] In addition, the rotating wheels 9 are evenly distributed along the central axis of the TC4 alloy billet 10 , and the circular surface formed by the track of the rotating wheels 9 acting on the surface of the TC4 alloy billet 10 is perpendicular to the central axis of the TC4 alloy billet 10 .

[0013] In practice, the steps for preparing the titanium nitride coating on the surface of the TC4 alloy are as follows:

[0014] Step 1: Preparation of TiN

[0015] NH 3 NH in raw material tank 5 3 Enter TiCl through check valve 2 4 In the raw material tank 3, the two react at 1500-2000°C to generate TiN. At this time, TiCl 4 There are two phases of TiCl4 and TiN in the raw material tank 3;

[0016] Step 2: Replace Ti

[0017] The Si in the Si raw material tank 1 is heated and vaporized, and TiCl is input through the one-way valve 2. 4 In the raw material tank 3, Si is used to replace Ti in TiN at 1500-2000°C. At this time, TiCl 4 There are three phases of TiCl4, Ti and SiN in the raw material tank 3;

[0018] Step 3: Generate TiN

[0019] TiCl 4Ti in the raw material tank 3 is fed into the low temperature reaction box 7 through the one-way valve 2, and NH 3 The low temperature reaction box 7 is input through the one-way valve 2 and the pipeline 6. At this time, the heating jacket 8 is started to make Ti and NH 3 A reaction occurs in the low temperature reaction box 7 to generate TiN and H 2 ;

[0020] Step 4: Plastic deformation

[0021] The generated products TiN and H in the low temperature reaction box 7 are 2 The TC4 alloy billet 10 is input into the deposition box 4 and rotated along its own central axis to carry out TiN and H 2 The TC4 alloy billet 10 is attached and combined with the surface thereof. Meanwhile, the rotating wheel 9 is started so that its lower end acts on the surface of the TC4 alloy billet 10 to cause plastic deformation, thereby strengthening the surface of the TC4 alloy billet 10 .

[0022] The technical solution of the present invention has the following characteristics and beneficial effects:

[0023] First, the present invention proposes a method and a corresponding device for strengthening the surface of titanium alloy with titanium nitride at a relatively low temperature. By means of the device, TiCl 4 With NH 3 Then, at 1500-2000°C, the vaporized Si undergoes a substitution reaction with the TiN generated in step 1 to generate Ti; then, in a low temperature reaction box 7, at 400-700°C, the generated Ti reacts with NH 3 Reaction occurs to generate TiN and H 2 , and realize TiN and H 2 Adhesion and bonding on the surface of TC4 alloy. During the deposition process, the wheel 9 and hydrogenation reaction are used to promote the adhesion of TiN and achieve grain refinement on the surface of TC4 alloy.

[0024] Second, in TiN and H 2 During the process of attaching and bonding with the surface of TC4 alloy, the action of the rotating wheel 9 causes micro cracks on the surface of TC4 alloy. 2 Infiltration causes hydrogenation reaction on the surface of TC4 alloy, resulting in grain refinement. In addition, since hydrogenation reaction is an exothermic reaction, it also promotes the bonding between TiN and the surface matrix of TC4 alloy.

[0025] Third, the scheme of the present invention avoids high-temperature treatment above 4000°C, and indirectly adopts the method of replacing Ti from TiN. The subsequent process of TiN adhering and bonding to the surface of TC4 alloy is carried out at a lower temperature. The design of this method saves energy, reduces the difficulty of the process and the complexity of the device, and also avoids the damage to the performance structure of the TC4 alloy body. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the device described in the technical solution of the present invention DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments:

[0028] See attached Figure 1 As shown in the embodiment, the device for preparing the titanium nitride coating on the surface of the TC4 alloy includes a Si raw material tank 1, a TiCl 4 Raw material tank 3 and NH 3 Raw material tank 5, Si raw material tank 1 and NH 3 The raw material tank 5 is connected to the TiCl 4 Raw material tank 3 is connected, TiCl 4 The raw material tank 3 is connected to one end of the low temperature reaction box 7 through a one-way valve 2. 3 The raw material tank 5 is also connected to the above-mentioned end of the low-temperature reaction box 7 through the one-way valve 2 and the pipeline 6. The other end of the low-temperature reaction box 7 is connected to the deposition box 4. A heating sleeve 8 is arranged on the periphery of the low-temperature reaction box 7 and the deposition box 4. A TC4 alloy billet 10 is placed in the deposition box 4. The TC4 alloy billet 10 can rotate along its own central axis. A rotating wheel 9 is arranged on the inner wall of the deposition box 4. The lower end of the rotating wheel 9 acts on the surface of the TC4 alloy billet 10 to cause it to produce plastic deformation. The rotating wheels 9 are evenly distributed along the central axis of the TC4 alloy billet 10. The circular surface formed by the track of the rotating wheels 9 acting on the surface of the TC4 alloy billet 10 is perpendicular to the central axis of the TC4 alloy billet 10.

[0029] The steps of preparing a titanium nitride coating on the surface of TC4 alloy using the above device are as follows:

[0030] Step 1: Preparation of TiN

[0031] NH 3 NH in raw material tank 5 3 Enter TiCl through check valve 2 4 In the raw material tank 3, the two react at 1500-2000°C to generate TiN. At this time, TiCl 4 There are two phases of TiCl4 and TiN in the raw material tank 3;

[0032] Step 2: Replace Ti

[0033] The Si in the Si raw material tank 1 is heated and vaporized, and TiCl is input through the one-way valve 2. 4 In the raw material tank 3, Si is used to replace Ti in TiN at 1500-2000°C. At this time, TiCl 4 There are three phases of TiCl4, Ti and SiN in the raw material tank 3;

[0034] Step 3: Generate TiN

[0035] TiCl 4 Ti in the raw material tank 3 is fed into the low temperature reaction box 7 through the one-way valve 2, and NH 3 Through the one-way valve 2 and the pipeline 6, the low-temperature reaction box 7 is input, and the heating jacket 8 is started at 400-700℃ to make Ti and NH 3 A reaction occurs in the low temperature reaction box 7 to generate TiN and H 2 ;

[0036] Step 4: Plastic deformation

[0037] The generated products TiN and H in the low temperature reaction box 7 are 2 The TC4 alloy billet 10 is input into the deposition box 4 and rotated along its own central axis to carry out TiN and H 2 The TC4 alloy billet 10 is attached and combined with the surface thereof. Meanwhile, the rotating wheel 9 is started so that its lower end acts on the surface of the TC4 alloy billet 10 to cause plastic deformation, thereby strengthening the surface of the TC4 alloy billet 10 .

Claims

1. A method for preparing a titanium nitride coating on a TC4 alloy surface, characterized in that: The steps of this method are as follows: Step 1: At 1500-2000°C, TiCl4 and NH3 react to generate TiN; Step 2: Under the condition of 1500-2000° C., the vaporized Si undergoes a substitution reaction with the TiN generated in step 1 to generate Ti; Step 3: Under the condition of 400-700° C., the Ti generated in step 2 reacts with NH 3 to generate TiN and H 2 , and the TiN and H 2 are attached and combined on the surface of the TC4 alloy; Step 4: Apply pressure to the surface of the TC4 alloy to cause it to undergo plastic deformation, thereby completing surface strengthening of the TC4 alloy.

2. A device for implementing the method for preparing a titanium nitride coating on a TC4 alloy surface as claimed in claim 1, characterized in that: The device comprises a Si raw material tank (1), a TiCl4 raw material tank (3) and an NH3 raw material tank (5). The Si raw material tank (1) and the NH3 raw material tank (5) are respectively connected to the TiCl4 raw material tank (3) through a one-way valve (2). The TiCl4 raw material tank (3) is connected to one end of a low-temperature reaction box (7) through the one-way valve (2). The NH3 raw material tank (5) is also connected to the above-mentioned end of the low-temperature reaction box (7) through the one-way valve (2) and a pipeline (6). The other end of the low-temperature reaction box (7) is connected to a deposition box (4). A heating sleeve (8) is arranged on the periphery of the low-temperature reaction box (7) and the deposition box (4). A TC4 alloy billet (10) is placed in the deposition box (4). The TC4 alloy billet (10) can rotate along its own central axis. A rotating wheel (9) is arranged on the inner wall of the deposition box (4). The lower end of the rotating wheel (9) acts on the surface of the TC4 alloy billet (10) to cause it to undergo plastic deformation.

3. The device for realizing the method of preparing titanium nitride coating on the surface of TC4 alloy according to claim 2, characterized in that: The rotating wheels (9) are evenly distributed along the central axis of the TC4 alloy billet (10), and the circular surface formed by the track of the rotating wheels acting on the surface of the TC4 alloy billet (10) is perpendicular to the central axis of the TC4 alloy billet (10).

4. According to the device of claim 2 or 3, the steps of preparing the titanium nitride coating on the surface of the TC4 alloy are as follows: Step 1: Preparation of TiN The NH3 in the NH3 raw material tank (5) is input into the TiCl4 raw material tank (3) through the one-way valve (2), so that the two react at 1500-2000° C. to generate TiN. At this time, two physical phases, TiCl4 and TiN, exist in the TiCl4 raw material tank (3); Step 2: Replace Ti The Si in the Si raw material tank (1) is heated and gasified, and then fed into the TiCl4 raw material tank (3) through a one-way valve (2), so that the Si replaces the Ti in the TiN at 1500-2000°C. At this time, three phases of TiCl4, Ti and SiN exist in the TiCl4 raw material tank (3); Step 3: Generate TiN The Ti in the TiCl4 raw material tank (3) is input into the low temperature reaction box (7) through the one-way valve (2), and the NH3 in the raw material tank (5) is input into the low temperature reaction box (7) through the one-way valve (2) and the pipeline (6). At this time, the heating jacket (8) is started to react with Ti and NH3 in the low temperature reaction box (7) at 400-700°C to generate TiN and H2; Step 4: Plastic deformation The generated products TiN and H2 in the low-temperature reaction box (7) are input into the deposition box (4), and the TC4 alloy billet (10) is rotated along its own central axis to attach and combine TiN and H2 on the surface of the TC4 alloy billet (10). At the same time, the rotating wheel (9) is started so that its lower end acts on the surface of the TC4 alloy billet (10) to cause plastic deformation, thereby strengthening the surface of the TC4 alloy billet (10).

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