Preparation method of metal rhodium coating with characteristic of low adhesion with pure gold

Abstract

The invention discloses a preparation method of a metal rhodium coating with the characteristic of low adhesion with pure gold. The preparation method comprises the following steps: carrying out mechanical polishing and electrolytic polishing pretreatment on a titanium material to obtain a base material; the method comprises the following steps: placing a base material in a chamber of magnetron sputtering equipment, continuously vacuumizing the chamber, vacuumizing the chamber of the magnetron sputtering equipment to 5.0 * 10 <-4 > Pa, heating a titanium material to 25-300 DEG C, introducing argon until the vacuum degree reaches 0.3 Pa, and carrying out magnetron sputtering for 5-40 minutes to obtain the compact rhodium coating. The magnetron sputtering method is adopted to replace a traditional electroplating method, use of a strong-corrosivity heavy metal solution is avoided, and environmental friendliness is remarkably improved.

Description

Technical Field

[0001] The present invention relates to a surface treatment technology for spacecraft materials, and in particular to the preparation of a plating layer at the end of a spacecraft locking and releasing mechanism. The invention aims to provide a method for preparing a rhodium plating layer having low adhesion properties to pure gold by magnetron sputtering technology in a vacuum environment. Background Art

[0002] Each detector in the Tianqin program is equipped with a locking and release mechanism and a test mass. As a key component for gravitational wave detection, the test mass needs to be fixed by the locking and release mechanism before the detector is launched into the predetermined orbit. After reaching the orbit, the locking and release mechanism releases the test mass, putting it in a suspended state for gravitational wave detection. However, the continuous locking state of the locking and release mechanism before the spacecraft is launched may cause cold welding between the push rod and the test mass. The adhesion force generated during release will affect the suspension state of the test mass. Especially in a high vacuum environment, the adhesion effect of clean metal surfaces is particularly significant. Since the surface of the test mass is made of pure gold, the adhesion problem mainly comes from the interaction between gold and the end material of the locking and release mechanism.

[0003] To solve this problem, preparing a coating on the surface of the push rod that has no adhesion to pure gold can effectively prevent cold welding and reduce adhesion. Given that gold and rhodium are incompatible below 500°C, rhodium coating becomes an ideal choice for improving cold welding and adhesion behavior. At present, electroplating is a common technology for preparing rhodium films. For example, Chinese patent CN101985765A introduces a method for electroplating rhodium layers based on rhodium sulfate solution. However, the electroplating process has the risk of environmental pollution due to the leakage of heavy metal ions, and the interface bonding strength between the film substrate and the coating prepared by the electroplating method is insufficient, making it difficult to meet the needs of actual applications. In addition, the literature (Marot L, Covarel G, Tuilier M H. Adhesion of rhodium films on metallic substrates. Thin Solid Films, 2008, 516: 7604–7608) reported the use of magnetron sputtering to prepare rhodium coatings on copper, molybdenum and stainless steel substrates. Although the film bonding strength measured by the scratch test was 8.8-12.6N, it still failed to meet the technical requirements of the spacecraft locking and release mechanism. Summary of the Invention

[0004] The present invention relates to a surface treatment technology for spacecraft materials, and in particular to the preparation of a coating on the end of a spacecraft locking and releasing mechanism. The invention aims to provide a method for preparing a rhodium coating having low adhesion to gold by magnetron sputtering technology in a vacuum environment, so as to solve the adhesion problem between the spacecraft locking and releasing mechanism and the test mass, and to provide a process basis and solution for preparing high-quality rhodium films on the surfaces of substrates such as titanium.

[0005] The technical solutions adopted in the present invention are as follows:

[0006] A method for preparing a metal rhodium plating layer having low adhesion to pure gold comprises the following steps:

[0007] S1: Pre-treating the titanium material by mechanical polishing and electrolytic polishing to obtain a substrate.

[0008] S2: Place the pretreated substrate and rhodium target in the chamber of the magnetron sputtering equipment, and continuously evacuate the chamber to a vacuum of 5.0×10 -4 Pa, heat the titanium material to a temperature within the range of 25°C to 300°C, introduce argon gas until the vacuum degree reaches 0.3 Pa, and perform magnetron sputtering for 5 minutes to 40 minutes to obtain a dense rhodium coating.

[0009] The titanium material in S1 is pure titanium and its alloy products.

[0010] The electrolytic polishing solution for the titanium material in step S1 contains a perchloric acid / methanol ratio of 1:9 by volume, 2.91 g / L citric acid, and 83.33 ml / L glycerol. Polishing parameters are: voltage 25 V, room temperature, and polishing time 18 seconds. After polishing, the sample is ultrasonically cleaned with acetone for 15 minutes, followed by ultrasonic cleaning with ethanol and deionized water for 15 minutes each, and then dried with a hair dryer.

[0011] In S2 , the purity of the rhodium target was 99.99%, and Ar gas with a purity of 99.999% was used as the sputtering gas.

[0012] In S2, the magnetron sputtering parameters are: the chamber vacuum degree during sputtering is 5.0×10 -4 Pa, Ar gas flow rate of 15 sccm, working pressure of 0.3 Pa, sputtering power of 30 W, substrate temperature of 25°C to 300°C, and deposition time of 5 to 40 minutes. Before the actual sputtering, adjust the power to 30 W and pre-sputter for 10 minutes. After the actual sputtering is completed, wait until the substrate temperature drops to room temperature, open the chamber cover and remove the sample.

[0013] The above technical solution of the present invention has the following advantages compared with the prior art:

[0014] 1. The present invention adopts magnetron sputtering to replace the traditional electroplating method, avoiding the use of highly corrosive heavy metal solutions and significantly improving environmental friendliness.

[0015] 2. The present invention achieves precise control of the coating thickness by precisely controlling the sputtering parameters, while ensuring excellent bonding between the substrate and the coating, fully meeting practical application requirements.

[0016] 3. The Rh coating preparation method provided by the present invention is simple to operate, has good repeatability, and has high universality, and is suitable for the surface treatment of various substrate materials.

[0017] 4. Under specific sputtering conditions, the resulting coating thickness is 300nm and has a bonding strength of up to 16N. More importantly, high-temperature diffusion studies have shown that there is no diffusion behavior between the coating and pure gold, demonstrating excellent low-adhesion properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is the X-ray diffraction pattern of the rhodium coating on the titanium surface of the present invention

[0020] Figure 2 This is a scanning electron micrograph of the rhodium coating on the titanium surface of the present invention.

[0021] Figure 3 The bonding strength curve and scratch scanning electron micrograph of the rhodium coating on the titanium surface of the present invention are shown in FIG.

[0022] Figure 4 Energy spectrum of pure gold and rhodium coating after treatment at 400℃ for 3 hours DETAILED DESCRIPTION

[0023] To make the technical solutions and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention:

[0024] Example 1

[0025] A method for preparing a metal rhodium plating layer having low adhesion to pure gold comprises the following steps:

[0026] S1: Pre-treating the titanium material by mechanical polishing and electrolytic polishing to obtain a substrate.

[0027] S2: Place the pretreated titanium material in the chamber of the magnetron sputtering equipment, and continuously evacuate the chamber to a vacuum of 5.0×10 -4 Pa, heat the titanium material to a temperature within the range of 25°C to 300°C, introduce argon gas until the vacuum degree reaches 0.3 Pa, and perform magnetron sputtering for 5 minutes to 40 minutes to obtain a dense rhodium coating.

[0028] The titanium material in S1 is industrial pure titanium TA1.

[0029] The electrolytic polishing solution for titanium in S1 contained a perchloric acid / methanol ratio of 1:9 by volume, 2.91 g / L citric acid, and 83.33 ml / L glycerol. Polishing parameters were: 25 V, room temperature, and 18 seconds. After polishing, the sample was ultrasonically cleaned with acetone for 15 minutes, followed by ultrasonic cleaning with ethanol and deionized water for 15 minutes each, and then dried with a hair dryer.

[0030] In S2 , the target material is a metal rhodium target with a purity of 99.99%, and Ar gas with a purity of 99.999% is used as the sputtering gas.

[0031] In S2, the magnetron sputtering parameters are: the chamber vacuum degree during sputtering is 5.0×10 -4 The conditions were 15 sccm Ar gas flow, 0.3 Pa working pressure, 30 W sputtering power, 100°C substrate temperature, and 20 min deposition time. Before the actual sputtering, the power was adjusted to 30 W and a pre-sputtering period of 10 min was performed. After the actual sputtering was completed, the chamber cover was opened and the sample was removed after the substrate temperature cooled to room temperature.

[0032] Example 2

[0033] A method for preparing a metal rhodium plating layer having low adhesion to pure gold, characterized by comprising the following steps:

[0034] S1: Pre-treating the titanium material by mechanical polishing and electrolytic polishing to obtain a substrate.

[0035] S2: Place the pretreated titanium material in the chamber of the magnetron sputtering equipment, and continuously evacuate the chamber to a vacuum of 5.0×10 -4 Pa, heat the titanium material to a temperature within the range of 25°C to 300°C, introduce argon gas until the vacuum degree reaches 0.3 Pa, and perform magnetron sputtering for 5 minutes to 40 minutes to obtain a dense rhodium coating.

[0036] The titanium material in S1 is industrial pure titanium TA1.

[0037] The electrolytic polishing solution for titanium in S1 contained a perchloric acid / methanol ratio of 1:9 by volume, 2.91 g / L citric acid, and 83.33 ml / L glycerol. Polishing parameters were: 25 V, room temperature, and 18 seconds. After polishing, the sample was ultrasonically cleaned with acetone for 15 minutes, followed by ultrasonic cleaning with ethanol and deionized water for 15 minutes each, and then dried with a hair dryer.

[0038] In S2 , the target material is a metal rhodium target with a purity of 99.99%, and Ar gas with a purity of 99.999% is used as the sputtering gas.

[0039] In S2, the magnetron sputtering parameters are: the chamber vacuum degree during sputtering is 5.0×10 -4 The conditions were 15 sccm Ar gas flow, 0.3 Pa working pressure, 30 W sputtering power, 300°C substrate temperature, and 20 min deposition time. Before the actual sputtering, the power was adjusted to 30 W and a pre-sputtering period of 10 min was performed. After the actual sputtering was completed, the chamber cover was opened and the sample was removed after the substrate temperature cooled to room temperature.

[0040] In S2, the X-ray diffraction pattern of the Rh coating was obtained. Figure 1 As shown in Figure 2, the Rh coating still has a face-centered cubic structure. The surface morphology of the Rh coating is as follows: Figure 2 As shown, the coating is a dense continuous film. The Rh coating adhesion test curve is as follows Figure 3 As shown in the figure, the bonding force is 16 N. After the Au / Rh composite coating is treated at 400℃ for 3 hours, the energy spectrum of the pure gold and rhodium coating is as follows: Figure 4 As shown in the figure, no element diffusion is observed, that is, the adhesion between Au and Rh is weak.

[0041] Example 3

[0042] A method for preparing a metal rhodium plating layer having low adhesion to pure gold comprises the following steps:

[0043] S1 performs mechanical polishing and electrolytic polishing pretreatment on the titanium material to obtain a base material.

[0044] S2 placed the pretreated titanium material in the chamber of the magnetron sputtering equipment and continuously evacuated the chamber to a vacuum of 5.0×10 -4 Pa, heat the titanium material to a temperature within the range of 25°C to 300°C, introduce argon gas until the vacuum degree reaches 0.3 Pa, and perform magnetron sputtering for 5 minutes to 40 minutes to obtain a dense rhodium coating.

[0045] The titanium material in S1 is industrial pure titanium TA1.

[0046] The electrolytic polishing solution for titanium in S1 contained a perchloric acid / methanol ratio of 1:9 by volume, 2.91 g / L citric acid, and 83.33 ml / L glycerol. Polishing parameters were: 25 V, room temperature, and 18 seconds. After polishing, the sample was ultrasonically cleaned with acetone for 15 minutes, followed by ultrasonic cleaning with ethanol and deionized water for 15 minutes each, and then dried with a hair dryer.

[0047] In S2 , the target material is a metal rhodium target with a purity of 99.99%, and Ar gas with a purity of 99.999% is used as the sputtering gas.

[0048] In S2, the magnetron sputtering parameters are: the chamber vacuum degree during sputtering is 5.0×10 -4 The conditions were: 15 sccm Ar gas flow, 0.3 Pa working pressure, 30 W sputtering power, 25°C substrate temperature, and 20 min deposition time. Before the actual sputtering, the power was adjusted to 30 W and a pre-sputtering period of 10 min was performed. After the actual sputtering was completed, the chamber cover was opened and the sample was removed after the substrate temperature cooled to room temperature.

[0049] Example 4

[0050] A method for preparing a metal rhodium plating layer having low adhesion to pure gold comprises the following steps:

[0051] S1: Pre-treating the titanium material by mechanical polishing and electrolytic polishing to obtain a substrate.

[0052] S2: Place the pretreated titanium material in the chamber of the magnetron sputtering equipment, and continuously evacuate the chamber to a vacuum of 5.0×10 -4 Pa, heat the titanium material to a temperature within the range of 25°C to 300°C, introduce argon gas until the vacuum degree reaches 0.3 Pa, and perform magnetron sputtering for 5 minutes to 40 minutes to obtain a dense rhodium coating.

[0053] The titanium material in S1 is industrial pure titanium TA1.

[0054] The electrolytic polishing solution for titanium in S1 contained a perchloric acid / methanol ratio of 1:9 by volume, 2.91 g / L citric acid, and 83.33 ml / L glycerol. Polishing parameters were: 25 V, room temperature, and 18 seconds. After polishing, the sample was ultrasonically cleaned with acetone for 15 minutes, followed by ultrasonic cleaning with ethanol and deionized water for 15 minutes each, and then dried with a hair dryer.

[0055] In S2 , the target material is a metal rhodium target with a purity of 99.99%, and Ar gas with a purity of 99.999% is used as the sputtering gas.

[0056] In S2, the magnetron sputtering parameters are: the chamber vacuum degree during sputtering is 5.0×10 -4 The conditions were 15 sccm Ar gas flow, 0.3 Pa working pressure, 30 W sputtering power, 300°C substrate temperature, and 40 min deposition time. Before the actual sputtering, the power was adjusted to 30 W and a pre-sputtering period of 10 min was performed. After the actual sputtering was completed, the chamber cover was opened and the sample was removed after the substrate temperature cooled to room temperature.

[0057] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a metal rhodium plating layer having low adhesion to pure gold, characterized in that include: The titanium material is subjected to mechanical polishing and electrolytic polishing pretreatment to obtain a base material; The rhodium target and substrate were placed in the chamber of the magnetron sputtering equipment, and the chamber was continuously vacuumed to 5.0×10 -4 Pa, heat the titanium material to a temperature within the range of 25°C to 300°C, introduce argon gas until the vacuum degree reaches 0.3 Pa, and perform magnetron sputtering for 5 minutes to 40 minutes to obtain a dense rhodium coating.

2. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 1, wherein: The titanium material is pure titanium and its alloy products.

3. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 2, wherein: The composition of the electrolytic polishing solution for titanium materials is: the volume ratio of perchloric acid and methanol is 1:9, the citric acid content is 2.91g / L, and the glycerol content is 83.33ml / L.

4. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 2, wherein: When electrolytic polishing titanium materials, the polishing parameters are: voltage 25V, room temperature, and polishing time 18s.

5. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 4, wherein: After polishing, the sample was first ultrasonically cleaned with acetone for 15 min, then ultrasonically cleaned with ethanol and deionized water for 15 min respectively, and then dried with a hair dryer.

6. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 1, wherein: The purity of the rhodium target material is 99.99%, and Ar gas with a purity of 99.999% is used as the sputtering gas.

7. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 1, wherein: Before formal sputtering, adjust the power to 30W and pre-sputter for 10 minutes.

8. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 1, wherein: The chamber vacuum degree during sputtering was 5.0×10 -4 Pa, the Ar gas flow rate is 15 sccm, the working gas pressure is 0.3 Pa, and the sputtering power is 30 W.

9. The method for preparing a metal rhodium plating layer having low adhesion to pure gold according to claim 1, wherein: During sputtering, the substrate temperature is 25°C to 300°C, and the deposition time is 5min to 40min. After the formal sputtering is completed, wait for the substrate temperature to drop to room temperature, open the cavity cover and take out the sample.

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