An insulating hard structure suitable for a threaded member surface and a method of making the same

Abstract

The application discloses an insulating hard structure suitable for a threaded part surface and a preparation method thereof, which comprises a metal transition layer arranged on a base body and an insulating hard coating arranged on the metal transition layer. The insulating hard structure can endow the threaded part surface with the insulating characteristic, so that no current passes when the threaded part surface contacts with another threaded part. Compared with directly installing an insulating gasket between the two threaded parts, the insulating hard structure is simpler and more reliable. The insulating hard structure is composed of aluminum oxide, titanium oxide and zirconium oxide with excellent stability, and is stable, reliable and long in service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating preparation, and more particularly to an insulating hard structure suitable for the surface of a threaded part and a preparation method thereof. BACKGROUND

[0002] There is a requirement for mutual insulation between some metal threaded parts of a hydroelectric generator set. Currently, an insulating sleeve and an insulating pad are used between two threaded parts. However, the material of the insulating sleeve and the insulating pad is mostly phenolic cloth. The strength of the material is not enough, and the insulating sleeve and the insulating pad are easily crushed during installation and maintenance of the threaded parts, thereby losing the insulating effect. In addition, the service life of the insulating sleeve and the insulating pad is limited, thereby limiting the long-term use of the special threaded parts. Therefore, in order to solve the above problems, a new type of insulating facility is needed to obtain the insulating properties of the surface of the metal threaded parts and to prolong the service life of the threaded parts. SUMMARY

[0003] The present application aims to provide an insulating hard structure suitable for the surface of a threaded part and a preparation method thereof, so as to solve the technical problems in the background art.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] An insulating hard structure suitable for the surface of a threaded part, comprising:

[0006] a metal transition layer, which is arranged on the substrate;

[0007] an insulating hard coating layer, which is arranged on the metal transition layer.

[0008] In some embodiments, the insulating hard coating layer comprises three sub-coating layers, each of which is one of an Al2O3 coating layer, a TiO2 coating layer or a ZrO2 coating layer; and the materials of adjacent two sub-coating layers are different.

[0009] In some embodiments, the thickness of the metal transition layer is 50-250 nm.

[0010] In some embodiments, the material of the metal transition layer is one of metal Ti, Zr or Cr.

[0011] In some embodiments, the overall hardness of the insulating hard structure is 3.5-27.5 GPa, the film-substrate bonding strength with different metal substrate materials is 5-45 N, and the overall resistivity is 0.00004-0.005 Ωm.

[0012] In some embodiments, the thickness of each sub-coating layer is controlled to be 0.1-2.5 μm.

[0013] The embodiment also provides a preparation method of the insulating hard structure suitable for the surface of the threaded part, comprising the following steps:

[0014] (1) inert gas is introduced into the cavity, a bias power supply is turned on and a bias range of -235 to -50 V is set, ion surface etching of the threaded part substrate is performed for a set time, and the etching time is 2.5 to 10 min;

[0015] (2) inert gas is introduced into the cavity, the vacuum degree of the cavity is kept at 0.55 to 1.35 Pa, a direct current voltage is loaded on a Ti, Zr or Cr metal target, the loading power is 150 to 455 W, a metal transition layer is deposited on the threaded part, and the deposition time is controlled to be 2 to 35 min;

[0016] (3) inert gas is introduced into the cavity, the gas flow rate is kept at 40 to 75 sccm, the vacuum degree of the cavity is kept at 0.75 to 1.65 Pa, a radio frequency voltage is loaded on one of three Al2O3, TiO2 and ZrO2 ceramic targets, a first layer of sub-coating is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min;

[0017] (4) inert gas is introduced into the cavity, the gas flow rate is kept at 40 to 75 sccm, the vacuum degree of the cavity is kept at 0.75 to 1.65 Pa, a radio frequency voltage is loaded on a target different from the target in the step (3) of the three Al2O3, TiO2 and ZrO2 ceramic targets, a second layer of sub-coating is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min;

[0018] (5) inert gas is introduced into the cavity, the gas flow rate is kept at 40 to 75 sccm, the vacuum degree of the cavity is kept at 0.75 to 1.65 Pa, a radio frequency voltage is loaded on a target different from the target in the step (3) and the step (4) of the three Al2O3, TiO2 and ZrO2 ceramic targets, the loading power is 50 to 155 W, the frequency of the radio frequency is fixed at 65 to 95 MHz, a second layer of sub-coating is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min;

[0019] (6) the threaded part with the deposited coating is heated to 250 to 650 DEG C in the cavity, and is kept for 35 to 155 min, so as to obtain the insulating hard coating suitable for the surface of the threaded part.

[0020] In some embodiments, in the step (2), the gas flow rate is kept at 44 to 85 sccm.

[0021] In some embodiments, in the step (3), the loading power is 50 to 155 W, and the frequency of the radio frequency is fixed at 65 to 95 MHz.

[0022] In some embodiments, the loading power in step (4) is 50-155 W, and the frequency of the radio frequency is fixed at 65-95 MHz.

[0023] The present application has the following beneficial effects compared with the prior art:

[0024] (1) The insulating hard structure can impart the surface of the threaded part with the characteristic of insulation, so that no current passes when it is in contact with another threaded part, which is simpler and more reliable than directly installing an insulating gasket between the two threaded parts.

[0025] (2) The insulating hard structure is composed of alumina, titania and zirconia with excellent stability, and has stable and reliable performance and long service life.

[0026] (3) The insulating hard structure has high hardness and high film-substrate bonding strength, can bear the threaded contact stress, and is not easy to be damaged during threaded installation.

[0027] (4) The insulating hard structure has good universality and significant industry promotion value on the surface of parts under similar working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Schematic diagram of the hard insulating coating structure suitable for threaded parts;

[0029] Figure 2 Scanning electron microscope morphology diagram of the hard insulating coating structure suitable for threaded parts; DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiments of the present application will be described in more detail below in combination with the drawings of the preferred embodiments of the present application. In the drawings, the same or similar reference numerals represent the same or similar components or components with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, not all embodiments. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] The embodiments of the present application will be described in detail below in combination with the drawings.

[0032] In the description of the application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connect" should be understood in a broad sense, for example, it can be fixedly connected, it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0033] In the description of the application, it is necessary to understand that the terms "up", "down", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the application.

[0034] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or display including a series of steps or units need not be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or displays.

[0035] The following will be combined with Figure 1 A kind of insulating hard structure suitable for the surface of threaded part and its preparation method related to the embodiment of the application will be described in detail.It is worth noting that the following embodiments are only used to explain the application and do not constitute a limitation on the application.

[0036] Example 1:

[0037] Referring to Figure 1 As shown in a kind of insulating hard structure suitable for the surface of threaded part, it includes: metal transition layer 5, the metal transition layer is arranged on base body 4;Insulating hard coating, the insulating hard coating is arranged on metal transition layer.The coating contains three layers of sub-coating, the thickness of each layer of sub-coating is controlled at 0.1 ~ 2.5 μm, each layer of sub-coating is one of Al2O3 coating 1, TiO2 coating 2 or ZrO2 coating 3;Each layer of sub-coating material is one of Al2O3, TiO2 or ZrO2, and the materials of adjacent two coatings are not same.The structure diagram of coating is as shown in Figure 1 Metal transition layer with the thickness of 50 ~ 250 nm is arranged between coating and base body, the material of transition layer is one of metal Ti, Zr or Cr.The overall hardness of the coating is 3.5 ~ 27.5 GPa, the film base bonding strength with different metal base body materials is 5 ~ 45 N, and the overall resistivity is 0.00004 ~ 0.005 Ωm.

[0038] The application is prepared by using magnetron sputtering deposition technology. The magnetron sputtering coating machine used comprises at least four anode target heads, a bias power source can be used to perform ion etching on the surface of the substrate and assist the deposition of the coating, and at least one radio frequency power source on the target head can be used to load the ceramic target. In the preparation process, Al2O3, TiO2 and ZrO2 ceramic targets and Ti, Zr or Cr metal targets are used to deposit a coating with a set thickness on the surface of the threaded part after ion etching treatment. The coating preparation comprises the following steps:

[0039] (1) inert gas is introduced into the cavity, the bias power source is turned on and the bias voltage range is set to -235 to -50 V, the threaded part substrate is subjected to ion surface etching for a set time, and the etching time is 2.5 to 10 min;

[0040] (2) inert gas is introduced into the cavity, the gas flow rate is maintained at 44 to 85 sccm, the vacuum degree of the cavity is maintained at 0.55 to 1.35 Pa, a direct current voltage is loaded on the Ti, Zr or Cr metal target, the loading power is 150 to 455 W, a metal transition layer is deposited on the threaded part, and the deposition time is controlled to be 2 to 35 min;

[0041] (3) inert gas is introduced into the cavity, the gas flow rate is maintained at 40 to 75 sccm, the vacuum degree of the cavity is maintained at 0.75 to 1.65 Pa, a radio frequency voltage is loaded on one of the three Al2O3, TiO2 and ZrO2 ceramic targets, the loading power is 50 to 155 W, the frequency of the radio frequency is fixed at 65 to 95 MHz, a first layer of sub-coating is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min;

[0042] (4) inert gas is introduced into the cavity, the gas flow rate is maintained at 40 to 75 sccm, the vacuum degree of the cavity is maintained at 0.75 to 1.65 Pa, a radio frequency voltage is loaded on the target different from the target in step (3) of the three Al2O3, TiO2 and ZrO2 ceramic targets, the loading power is 50 to 155 W, the frequency of the radio frequency is fixed at 65 to 95 MHz, a second layer of sub-coating is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min;

[0043] (5) inert gas is introduced into the cavity, the gas flow rate is maintained at 40 to 75 sccm, the vacuum degree of the cavity is maintained at 0.75 to 1.65 Pa, a radio frequency voltage is loaded on the target different from the target in steps (3) and (4) of the three Al2O3, TiO2 and ZrO2 ceramic targets, the loading power is 50 to 155 W, the frequency of the radio frequency is fixed at 65 to 95 MHz, a second layer of sub-coating is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min;

[0044] (6) Heat the deposited threaded part in the cavity to 250-650°C and keep it at that temperature for 35-155 minutes to obtain an insulating hard coating suitable for the surface of the threaded part.

[0045] The cross-sectional morphology of the coating was observed using a scanning electron microscope as follows: Figure 2 As shown, the insulating hard coating consists of three sub-coatings: an Al₂O₃ sub-coating with a thickness of 0.44 μm, a TiO₂ sub-coating with a thickness of 1.73 μm, and a ZrO₂ sub-coating with a thickness of 0.45 μm. The hardness of the coating was measured to be 23.4 GPa using a nanoindenter, and the adhesion between the coating and the 45# steel substrate was measured to be 28.7 N using a scratch analyzer. The resistivity of the coating at room temperature (25°C) was measured to be 0.00024 Ωm using the four-probe method.

[0046] The above description is merely a preferred embodiment of the present invention and is intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing an insulating rigid structure suitable for the surface of threaded parts, characterized in that, Includes the following steps: (1) Inert gas is introduced into the cavity, the bias power supply is turned on and the bias range is set to -235~-50V, and the threaded substrate is subjected to ion surface etching for a set time of 2.5~10min. (2) Inert gas is introduced into the cavity to maintain the vacuum degree of the cavity between 0.55 and 1.35 Pa. A DC voltage is applied to the Ti, Zr or Cr metal target with a loading power of 150 to 455 W. A metal transition layer is deposited on the threaded part, and the deposition time is controlled to be 2 to 35 min. (3) Inert gas is introduced into the cavity, and the gas flow rate is maintained between 40 and 75 sccm. The vacuum degree of the cavity is maintained between 0.75 and 1.65 Pa. An RF voltage is applied to one of the three Al2O3, TiO2, and ZrO2 ceramic targets. The first sub-coating layer is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min. (4) Inert gas is introduced into the cavity, and the gas flow rate is maintained between 40 and 75 sccm. The vacuum degree of the cavity is maintained between 0.75 and 1.65 Pa. Radio frequency voltage is applied to the three Al2O3, TiO2 and ZrO2 ceramic targets that are different from those in step (3). A second sub-coating layer is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min. (5) Inert gas is introduced into the cavity, and the gas flow rate is maintained between 40 and 75 sccm. The vacuum degree of the cavity is maintained between 0.75 and 1.65 Pa. Radio frequency voltage is applied to three Al2O3, TiO2 and ZrO2 ceramic targets that are different from those in steps (3) and (4). The applied power is 50 to 155 W, and the radio frequency is fixed at 65 to 95 MHz. A second sub-coating layer is deposited on the threaded part, and the deposition time is controlled to be 150 to 450 min. (6) Heat the threaded part after deposition coating in the cavity to 250~650℃ and keep it at that temperature for 35~155min to obtain an insulating hard coating suitable for the surface of the threaded part.

2. The method for preparing an insulating rigid structure suitable for the surface of threaded parts according to claim 1, characterized in that... In step (2), the gas flow rate is maintained between 44 and 85 sccm.

3. The method for preparing an insulating rigid structure suitable for the surface of threaded parts according to claim 1, characterized in that... In step (3), the applied power is 50~155W and the radio frequency is fixed at 65~95MHz.

4. The method for preparing an insulating hard structure suitable for the surface of threaded parts according to claim 1, characterized in that... In step (4), the applied power is 50~155W and the radio frequency is fixed at 65~95MHz.

5. An insulating rigid structure suitable for the surface of threaded parts, characterized in that, The insulating rigid structure applicable to the surface of the threaded component is prepared by a method for preparing an insulating rigid structure applicable to the surface of a threaded component as described in any one of claims 1 to 4, and includes: A metal transition layer disposed on a substrate; An insulating hard coating is disposed on a metal transition layer.

6. An insulating rigid structure suitable for the surface of threaded parts according to claim 5, characterized in that, The insulating hard coating comprises three sub-coatings, each of which is one of Al2O3, TiO2, or ZrO2; and the materials of adjacent sub-coatings are different.

7. An insulating rigid structure suitable for the surface of threaded parts according to claim 5, characterized in that, The thickness of the metal transition layer is 50~250nm.

8. An insulating rigid structure suitable for the surface of threaded parts according to claim 5, characterized in that, The material of the metal transition layer is one of the metals Ti, Zr, or Cr.

9. An insulating rigid structure suitable for the surface of threaded parts according to claim 5, characterized in that, The overall hardness of the insulating rigid structure is 3.5~27.5GPa, the bonding strength with film substrates of different metal matrix materials is 5~45N, and the overall resistivity is 0.00004~0.005Ωm.

10. An insulating rigid structure suitable for the surface of threaded parts according to claim 6, characterized in that, The thickness of each sub-coating layer is controlled between 0.1 and 2.5 μm.

Images